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GOLD: 


ITS   GEOLOGICAL    OCCURRENCE    AND 
GEOGRAPHICAL   DISTRIBUTION 


BY 

J.  MALCOLM   MACLAREN,  D.Sc. 

*    /// 

Fellow  of  the  Geological  Society  ;    Fellow  of  the  Royal  Geographical  Society 
Member  of  the  Institution  of  Mining  and  Metallurgy 

Late  Mining  Specialist,  Government  of  India  ;  formerly  Assistant 
Government  Geologist,  Queensland  ;  etc. 

Sometime  New  Zealand  Government  Mining  Scholar  ; 

Senior  Scholar,   New  Zealand  University'  ; 

and  1851  Exhibition  Scholar 


With   One   Coloured   Plate  and   278   Illustrations 


LONDON  : 

&be  Wawxa  Journal 


1908 


All  Rights  Reserved 


T/V 

422 

Ms 

C*M 

1 

PREFACE. 


The  writer  who  would  add  one  more  treatise  to  the  litera- 
ture of  the  study  of  ore-deposits  must  needs  show  justification. 
He  must  present  either  new  facts  or  a  new  and  more 
scientific  arrangement  of  already-published  data.  It  is  hoped 
that,  to  some  degree  at  least,  both  these  ends  have  been 
attained  in  the  present  volume.  In  order  that  the  value  of 
the  collected  facts  may  be  in  no  wise  impaired  by 
possibly  erroneous  correlation,  speculative  inferences  have  here 
been  sharply  differentiated  from  the  data  of  observation.  This 
arrangement  of  the  subject  is  presented  with  the  more  con- 
fidence since  it  is  believed  that  absolute  progress  in  the  science 
of  ore -deposits  will,  in  the  future,  be  made  largely,  if  not 
entirely,  by  inductive  reasoning.  A  compilation  of  the  known 
facts  concerning  the  deposition  of  a  single  metal,  and  of 
one  possessing  fairly  well-defined  characters,  both  native  and 
in  combination,  has  therefore  seemed  a  not  unnecessary  contri- 
bution towards  the  foundation  on  which  a  stable  hypothesis 
of  ore-deposition  must  be  erected.  The  correlation  of  the 
data  obtained  has  for  the  present  been  considered  of  minor 
importance,  and  every  effort  has,  on  the  other  hand,  been 
directed  towards  the  presentation  in  readily  accessible  form 
of  the  salient  facts  of  auriferous  deposition. 

Some  apology  may  be  deemed  necessary  for  crudities  of 
style.  The  collection  of  data  was  commenced  without  any 
thought  of  publication,  and  the  book  itself  has  been  written 
during  a  period  snatched  from  professional  work — a  period 
that,  though  long  in  itself,  is  short  when  regard  is  had  to  the 
importance  of  the  subject.  The  literature  of  gold  is  stupendous, 
and  as  all  the  authorities  quoted,  with  hundreds  of  others, 
were  carefully  read,  and  as  the  contents  of  a  single  volume  of 


VI.  PREFACE. 

handy  size  are  limited,  it  has  been  necessary  to  sacrifice  other 
considerations  to  the  essential  claims  of  accuracy  and  brevity. 

Whatever  apologies  may  be  due  in  the  foregoing  respect, 
it  is  felt  that  none  are  necessary  in  respect  of  the  general  incon- 
clusiveness  and  vagueness  of  the  speculative  sections  of  the 
volume.  With  the  facts  at  command  inconclusiveness  is 
unavoidable  in  dealing  with  the  subject,  and  the  writer  or  pro- 
fessor who,  from  the  security  of  the  study  or  the  lecture-room, 
cries  order  where  there  is  no  order,  is  not  materially  advancing 
his  science,  inasmuch  as  the  student  on  passing  to  the  mine  and 
failing  to  observe  there  those  sharp  divisions  of  ores  and  ore- 
deposits  he  had  hitherto  looked  upon  as  fundamental,  is 
disposed  to  ascribe  the  lack  of  correspondence  between  hypo- 
thesis and  observation  to  an  innate  inability  to  grasp  the 
relations  of  the  subject,  and  the  services  of  a  promising  observer 
are  soon  lost  to  science.  Even  the  very  broad  grouping  of  gold- 
deposits  adopted  in  this  volume  must  certainly  be  materially 
modified  when  the  general  principles  underlying  auriferous 
deposition  come  to  be  more  fully  understood. 

In  the  collection  of  the  notes  embodied  herein  I  have 
visited  the  principal  gold-districts  of  Europe,  India,  Eastern 
and  Western  North  America,  Australia,  and  New  Zealand  ; 
the  data  adduced  for  other  regions  is  therefore  derived  entirely 
from  the  authorities  quoted.  Even  for  those  goldfields 
examined,  the  facts  obtained  have  in  the  majority  of  cases 
been  largely  the  result  of  the  observation  of  local  geologists, 
for  it  rarely  happens  that  a  sojourn  of  a  few  days  on  a  goldfield 
results  in  the  acquisition  of  new,  and  at  the  same  time  accurate 
information.  Often  the  sole,  but  by  no  means  unimportant 
result  of  personal  examination  has  been  the  ability  to  dis- 
criminate between  the  essential  and  the  trivial  in  the  published 
literature  of  the  given  field.  It  has  manifestly  been  impossible, 
even  had  it  been  desirable,  to  include  a  complete  bibliography 
of  the  literature  of  gold,  but  it  is  confidently  believed  that 
reference  to  the  authorities  quoted  will  give,  not  only  a  wide 


PREFACE.  Vll. 


conspectus  of  the  geological  knowledge  of  any  goldfield,  but 
also  a  fairly  complete  bibliography  of  its  literature,  since  those 
authorities,  who  follow  the  excellent  practice  of  including  biblio- 
graphies of  the  subject  treated,  have,  wherever  possible,  been 
cited. 

This  opportunity  is  gladly  taken  of  acknowledging  my 
obligation  to  Mr.  W.  Rupert  Jones,  Assistant  Librarian  of  the 
Geological  Society  of  London,  both  for  the  courtesy  with  which 
his  unique  bibliographical  knowledge  has  been  placed  at  my 
disposal,  and  for  his  complete  annual  catalogues  of  geological 
literature,  the  use  of  which  has  materially  lightened  the  labour 
of  research.  Acknowledgments  are  also  due  to  the  various 
mining  engineers  who  have  so  kindly  furnished  either  informa- 
tion or  illustrations ;  it  is  trusted  that  it  may  not  be 
deemed  invidious  to  mention  more  particularly  in  this  respect 
the  name  of  Messrs.  John  Taylor  and  Sons.  Finally,  my  in- 
debtedness must  be  expressed  to  those  scientific  societies  and 
geological  surveys  whose  volumes  have  been  laid  so  freely 
under  contribution  to  furnish  data  and  illustrations. 

Malcolm  Maclaren. 


London, 

November,  1908. 


I 


Abbreviations  of  Principal  Serials  cited. 


Abh.  k.-preuss.  geol.  Landesanst.     Abhandlungen  der  koniglich-preussischen  geologise  hen 

Landesanstalt.     Berlin. 
Amer.  Geol.     American  Geologist.     Minneapolis  (Minn.).     See  Econ.  Geol. 
Amer.  Jour.  Sci.     American  Journal  of  Science.     New  Haven  (Conn.). 
An.  Mus.  Nac.  Salvador.     Anales  del  Museo  Nagional  de  Salvador.     San  Salvador. 
Ann.  Chim.  Phys.     Annales  de  chimie  et  de  physique,  Paris. 
Ann.  des  Mines,  Paris.     Annales  des  Mines.     Paris. 
Ann.  Rep.  Bur.  Mines,  B.C.    Annual  Report  of  the  Bureau  of  Mines,  British  Columbia. 

Victoria  (B.C.). 
Ann.  Rep.  Dep.  Mines,  N.S.W.     Annual  Report  of  the  Department  of  Mines  and  Agri- 
culture, New  South  Wales.     Sydney. 
Ann.  Rep.  Dep.   Mines,  Queensl.     Annual  Report  of  the    Under  Secretary  for  Mines, 

Queensland.     Brisbane. 
Ann.  Rep.   Geol.  Surv.   Canada.     Annual  Report  of  the  Geological  Survey  of  Canada. 

Ottawa. 
Ann.  Rep.  Geol.  Surv.  Natal.    Annual  Report  of  the  Geological  Survey  of  Natal.    Pieter- 

maritzburg. 
Ann.  Rep.   Geol.  Surv.  Queensl.     Annual  Progress  Report  of  the  Geological  Survey  of 

Queensland.      Brisbane. 
Ann.  Rep.   Geol.   Surv.   Transvaal.      Annual  Report  of  the  Geological    Survey    of    the 

Transvaal.     Pretoria. 
Ann.  Rep.  Geol.  Surv.    W.  Austr.     Annual  Progress  Report  of  the  Geological  Survey. 

Perth  (W.  Austr.). 
Ann.  Rep.  Sec.   Mines,   Victoria.     Annual  Report  of  the  Secretary  of  Mines,  Victoria. 

Melbourne. 
Ann.  Rep.  State  Min.  Cal.     Annual  Report  of  the  State  Mineralogist,  California. 
Ann.  Rep.   U.S.  Geol.  Surv.     Annual  Report  of  the  United  States  Geological  Survey. 

Washington  (B.C.). 
Ann.  Sci.  Univ.  Jassy.    Annales  scientifiques  de  l'Universite  de  Jassy.    Jassy  (Rumania). 
Ann.  Soc.  geol.  Belg.     Annales  de  la  Societe  geologique  de  Belgique.     Liege. 
Archiv.  Mus.  Nac.  Rio  de  Janeiro.    Archivos  do  Museu  Nacional  do  Rio  de  Janeiro.    Rio 

de   Janeiro. 
Atti  R.  Ace.  Lincei,  Rendic.    Atti  della  Reale  Accademia  dei  Lincei,  Rendiconti.     Rome. 
Atti  R.  Ace.  Sci.  Torino.     Atti  della  Reale  Accademia  delle  Scienze  di  Torino.     Turin. 
Aust.   Min.  Stand.     Australian  Mining  Standard.     Sydney. 

Berichte  Chem.  Gesell.     Berichte  der  deutschen  chemischen  Gesellschaft.     Berlin. 
Berg-hiitt.  Jahrb.  Wien.     Berg-  und  huttenmannisches  Jahrbuch  der  kaiserlich-koniglichen 

Bergakademien  zu  Leoben  und  Pribram  und  der  koniglich-ungarischen  Bergaka- 
demie  zu  Schemnitz.     Vienna. 
Berg-  u.  Hiitt.  Zeit.     Berg-  und  Huttenmannische  Zeitung,  Freiburg. 
Bol.  Ing.  Minas,  Peril.     Boletin  del  Cuerpo  de  Ingenieros  de  Minas  del  Peru.     Lima. 
Boll.  Soc.  geog.  ital.    Bollettino  della  Societa  geographica  italiana.     Rome. 


X.  ABBREVIATIONS    OF 

Bol.  Soc.  Nac.  Mineria,  Santiago.    Boletin  de  la  Sociedad  Nacional  de  Mineria.    Santiago 

de  Chile. 
Bull.  Col.  State  Mining  Bur.     Bulletin  of  the  Californian  State  Mining  Bureau.     San 

Francisco. 
Bull.  Com.  g'col.  Russie.     Bulletins  du  Comite  geologique.     St.  Petersburg. 
Bull.  Com.  g'col.  Finlande.    Bulletin  de  la  Commission  geologique  de  Finlande.    Helsingfors. 
Bull.  Geol.  Sgc.  Am.     Bulletin  of  the  Geological  Society  of  America.     Rochester  (N.Y.). 
Bull.  Geol.  Surv.  Queensl.     Bulletin  of  the  Geological  Survey  of  Queensland  (Department 

of  Mines).    Brisbane. 
Bull.  Oeol.  Surv.   Victoria.     Bulletin  of  the  Geological  Survey  of  Victoria.     Melbourne. 
Bull.  Geol.  Surv.   W.  Austr.       Bulletin  of  the  Geological  Survey  of  Western  Australia. 

Perth  (W.  Austr.). 
Bull.  Geol.  Univ.  Col.     Bulletin  of  the  Department  of  Geology,  University  of  California. 

Berkeley  (Cal.). 
Bull.   Mus.  Hist.  not.  Paris.     Bulletin  du  Museum  d'Histoire  naturelle.     Palis. 
Bull.  N.Z.  Geol.  Surv.    Bulletin  of  the  New  Zealand  Geological  Survey.    Wellington  (N.Z.). 
Bull.  Soc.  beige  de  Geol.     Bulletin  de  la  Societe  beige  de  Geologie,  de  Paleontologie  et 

d'Hydrologie.     Brussels. 
Bull.  Soc.  franc.  Min.     Bulletin  de  la  Societe  francaise  de  Mineralogie.     Paris. 
Bull.  Soc.  geol.    Bulletin  de  la  Societe  geologique  de  France.     Paris. 
Bull.  Soc  g'cog.  Paris.  Bulletin  de  la  Societe  geographique  de  France.     Paris. 
Bull.  Soc.  a" Hist.  not.  Toulouse.    Bulletin  de  la  Societe  d'Histoire  naturelle  de  Toulouse. 

Toulouse. 
Bull.  Soc.  Indust.  Min.     Bulletin  de  la  Societe  de  l'lndustrie  Minerale.     St.  Etienne. 
Bull.  Soc.  oural.  Sci.  not.     Bulletin  de  la  Societe  ouralienne  d' Amateurs  des  Sciences 

naturelles.     Ekaterinburg. 
Bull.  U.S.  Geol.  Surv.    Bulletin  of  the  United  States  Geological  Survey.    Washington. 
Can.  Min.  Jour.    Canadian  Mining  Journal,  Ottawa. 

Centralbl.  f.  Min.    Centralblatt  fur  Mineralogie,  Geologie  und  Palaontologie.    Stuttgart. 
Chem.  Centralblatt.     Chemisches  Centralblatt,  Leipzig. 
Chem.  News.     Chemical  News.     London. 

Com.  geol.  Buss.     Bulletins  du  Comite  geologique.     St.  Petersburg. 
C.   R.   Acad.   Sci.   Paris.     Comptes-rendus  hebdomadaires  des  Seances  de  l'Academie 

des  Sciences.     Paris. 
C.   B.   Congres  geol.  internal.     Comptes-rendus  du  Congres  geologique  international. 
Cons.  Rep.    Diplomatic  and  Consular  Reports.     London. 
Echo  des  Mines.    Echo  des  Mines,  Paris. 
Econ.  Geol.     Economic  Geology.     Lancaster  (Pa.). 
Eng.  Mag.     Engineering  Magazine.  New  York. 
Eng.  Min.  Jour.    Engineering  and  Mining  Journal.    New  York. 
Expl.  geol.  Reg.  aurij.  Siberie.      Explorations  geologiques  dans  les  Regions  auriferes  de 

la  Siberie.     St.  Petersburg. 
Field  Columbian  Mus.     Field  Columbian  Museum  Publications.     Chicago  (111.). 
Foldt.  Korl.     Foldtani  Kozlony.     [Geological  Magazine.]      Budapest. 
Gen.  Rep.  Geol.  Surv.  India.    General  Report  on  the  Work  carried  on  by  the  Geological 

Survey  of  India.     Calcutta. 
Geogr.  Jour.    Geographical  Journal  (Royal  Geographical  Society).     London. 
Geol.  Foren.  Stockh.  Fdrh.    Geologiska  Foreningens  i  Stockholm  Forhandlingar.  Stockholm. 
Geol.  Mag.     Geological  Magazine.     London. 
Geol.  Surv.  Canada.       Geological  Survey  of  Canada.      Ottawa. 
Geol.  Surv.  Queensl.,  Publ.     Geological  Survey  of  Queensland  :    Publications.     Brisbane 

See  also  Ann.  Rep.  Dep.  Mines,  Queensl. 
Great  Britain  and  Ireland.     Home  Office.     Mines  and  Quarries.     General  Report  and 

Statistics.     London. 


PRINCIPAL    SERIALS    CITED.  XI. 

Jaarb.  Mijnw.  Ned.  O.-Ind.     Jaarboek  van  het  Mijnwezen  in  Nederlandsch  Oost-Indie. 

Amsterdam. 
Jahrb.  f.  Berg-  u.  Hiittenw.  Sachsen.    Jahrbuch  fiir  das  Berg-  und  Hiittenwesen  im  Konig- 

reiche   Sachsen.      Freiberg. 
Jahrb.  k.-Jc.  geol.  Reichsanst.     Jalirbuch  der  kaiserlich-koniglichen  geologischen  Reichs- 

anstalt.     Vienna. 
Jahrb.   k.-preuss.   geol.   Landesanst.     Jahrbuch  der  koniglich-preiissischen  geologischen 

Landesanstalt.     Berlin. 
Jahrb.   k.-unq.   geol.   Anst.     Jahrbuch  der  koniglick-ungarischen  geologischen  Anstalt. 

Budapest. 
Jahresb.  k.-ung.  geol.  Anst.    Jahresbericht  der  koniglich-ungarischen  geologischen  Anstalt. 

Budapest. 
Jour.  Am.  Chem.   Soc.     Journal  of  the  American  Chemical  Society,  Washington. 
Jour.  Asiat.  Soc.  Bengal.     Journal  and  Proceedings  of  the  Asiatic  Society  of  Bengal. 

Calcutta. 
Jour.  Canad.  Mining  Inst.     Journal  of  the  Canadian  Mining  Institute.     Ottawa. 
Jour.  Chem.  Soc.     Journal  of  the  Chemical  Society.     London. 
Jour.  Geol.,  Chicago.     Journal  of  Geology.     Chicago  (111.). 
Jour,  prakt.  Chem.    Journal  fiir  praktische  Chemie.     Leipzig. 
Jour.  Boy.  As.  Soc.    Journal  of  the  Royal  Asiatic  Society.    London. 
Jour.  Boy.  Soc.  N.S.W.     Journal  and  Proceedings  of  the  Royal  Society  of  New  South 

Wales.     Sydney. 
Jour.  Soc.  Arts.    Journal  of  the  Society  of  Arts.     London. 

Mater.  Geol.  Buss.     Materialien  zur  Geologie  Russlands.    Herausgegeben  von  der  kaiser- 
lichen   mineralogischen   Gesellschaft.      St.  Petersburg.      See   also  Materialen   zur 
Mineralogie  Russlands,  von  Kokscharov.    St.  Petersburg. 
Mem.  Com.  geol.  Bussie.     Memoires  du  Comite  geologique.     St.  Petersburg. 
Mem.  Geol.  Surv.  India.     Memoirs  of  the  Geological  Survey  of  India.     Calcutta. 
Mem.  Geol.  Surv.  N.S.  W.  Memoirs  of  the  Geological  Survey  of  New  South  Wales.  Sydney. 
Mem.  Geol.  Surv.  Victoria.    Memoirs  of  the  Geological  Survey  of  Victoria.    Melbourne. 
Mem.  Mysore  Geol.  Dep.     Memoirs  of  the  Mysore  Geological  Department.     Bangalore. 
Mem.  Soc.  cient.  "Ant.  Alzate."    Memorias  y  Revista  de  la  Sociedad  cientifica  "  Antonio 

Alzate."     Mexico. 
Min.   Mag.     The  Mineralogical  Magazine  and  Journal  of  the  Mineralogical  Society. 

London. 
Mines  and  Minerals.     Mines  and  Minerals.     Scran  ton  (Pa.). 
Min.  Mitth.    Mineral ogische  Mittheilungen  ;   von  Tschermak.    Vienna. 
M in.  Jour.     Mining  Journal.     Railway  and  Commercial  Gazette.     London. 
Mining  Mag.     Mining  Magazine.     New  York. 
Min.  Sci.  Press.     Mining  and  Scientific  Press.     San  Francisco. 
Min.   World.  Chic.     Mining  World,  Chicago. 
Monatsb.  deutsch.  geol.  Gesellsch.  Monatsberichte  der  deutschen  geologischen  Gesellschaft. 

Berlin. 
Mon.   U.S.  [Geol.    Surv.       Monographs    of    the     United     States    Geological     Survey. 

Washington  (D.C.). 
Natal  Bep.  Mining.    Natal  Report  on  the  Mining  Industry  of  Natal.    Pietermaritzburg. 
Nature.     Nature.     London. 

N.  J.  f.  Min.    Neues  Jahrbuch  fiir  Mineralogie,  Geologie  und  Palaontologie.  Stuttgart. 
N.S.W.  Dep.  Mines,  Min.  Besources.    New  South  Wales  Department  of  Mines.    Mineral 

Resources.      Sydney. 
N.Z.  Mines  Becord.     New  Zealand  Govt.  Mines  Record.     Wellington. 
Oesterr.  Zeit.  fiir  Berg-  u.  Hiitt.    Oesterreichische  Zeitschrift  fiir  Berg-  und  Hiittenwesen. 
Vienna. 


Xll.  ABBREVIATIONS     OF 

Papers  and  Rep.  Min.  and  Mining,  N.Z.  Papers  and  Reports  relating  to  Minerals  and 
Mining,  N.Z.     Wellington  (N.Z.). 

Perak  Gov.  Gaz.    Perak  Government  Gazette.    Taiping. 

Peterm.  Mitth.    Peterniann's  Mittheilungen.    Gotha. 

Phil.  Mag.     Philosophical  Magazine.     London. 

Pogg.  Ann.     Annalen  von  Poggendorff.     Halle. 

Proc.  Gottesw.  Nat.  F.G.  Proceedings  of  the  Cotteswold  Naturalists'  Field  Club.  Gloucester. 

Proc.  Geol.  Soc.  S.A.  Proceedings  of  the  Geological  Society  of  South  Africa.    Johannesburg. 

Proc.  Inst.  G.E.    Minutes  and  Proceedings  of  the  Institution  of  Civil  Engineers.    London. 

Proc.  Linn.  Soc.  N.  S.  W.    Proceedings  of  the  Linnean  Society  of  New  South  Wales.  Sydney. 

Proc.  Rhodesia  Sci.  Assoc.    Proceedings  of  the  Rhodesia  Scientific  Association.    Bulawayo. 

Proc.  Roy.  Soc.   Victoria.     Proceedings  of  the  Royal  Society  of  Victoria.     Melbourne. 

Proc.  and  Trans.  N.S.  Inst.  Sci.  Proceedings  and  Transactions  of  the  Nova  Scotia  Institute 
of  Science.     Halifax  (N.S.). 

Prof.  Papers,  U.S.  Geol.  Surv.  Professional  Papers.  United  States  Geological  Survey. 
Washington. 

Q.  J.  G.  S.     Quarterly  Journal  of  the  Geological  Society.     London. 

Rec.  Geol.  Surv.  India.     Records  of  the  Geological  Survey  of  India.     Calcutta. 

Rec.  Geol.  Surv.  N.S.  W.    Records  of  the  Geological  Survey  of  New  South  Wales.    Sydney. 

Rec.  Geol.  Surv.  Victoria.     Records  of  the  Geological  Survey  of  Victoria.     Melbourne. 

Rep.  Austral.  Assoc.  Adv.  Sci.  Report  of  the  Australasian  Association  for  the  Advance- 
ment of  Science.     Sydney. 

Rep.  Bur.  Mines,  Canad.     Report  of  the  Bureau  of  Mines,  Canada.     Ottawa. 

Rep.  Dep.  Mines,  Mysore.    Report  of  the  Chief  Inspector  of  Mines  in  Mysore.    Bangalore. 

Rep.  Dep.  Mines,  N.S.    Report  of  the  Department  of  Mines,  Nova  Scotia.    Halifax  (N.S.). 

Rep.  Dep.  Mines,  N.S.  W.    Report  of  the  Secretary  of  the  Department  of  Mines.    Sydney. 

Rep.  Dep.  Mines,  Transvaal.    See  Transvaal  Mines  Dep. 

Rep.  Dep.  Mines,  Vict.     Report  of  the  Department  of  Mines,  Victoria.     Melbourne. 

Rep.  Dep.  Mines,  W.  Austr.  Report  of  the  Department  of  Mines,  Western  Australia. 
Perth   (W.   Austr.). 

Rep.  Geol.  Surv.  Newfoundland.  Report  of  the  Geological  Survey  of  Newfoundland. 
St.  John's  (N.F.). 

Rep.  Geol.  Surv.  Queensland.     Report  of  the  Geological  Survey  of  Queensland.     Brisbane. 

Rep.  Geol.  Surv.  Transvaal.     See  Transvaal  Mines  Dep.,  Rep.  Geol.  Surv. 

Rep.  Inst.  Mines  &  Forests,  Brit.  Guiana.  Report  of  the  Council  of  the  Institute  of  Mines 
and  Forests  on  the  Gold  and  Forest  Industries  of  British  Guiana.  Georgetown 
(Demerara). 

Rep.  Ontario  Bur.  Mines.    Report  of  the  Ontario  Bureau  of  Mines.    Toronto. 

Rep.  Surv.  Dep.  Egypt.     Report  on  the  Work  of  the  Survey  Department.     Cairo. 

Rev.  Sci.     Revue  Scientifique.     Paris. 

Russ.  Min.  Gesell.     See  Verh.  russ.-k.  Min.  Gesellsch. 

St.  Petersburg  Min.  Soc.    See  Verh.  russ.-k.  Min.  Gesellsch. 

Tasm.  Dep.  Mines.     Reports  of  the  Department  of  Mines,  Tasmania.     Hobart. 

Trans.  Am.  Inst.  M.E.  Transactions  of  the  American  Institute  of  Mining  Engineers. 
New  York. 

Trans.  Austr.  Inst.  M.E.  Transactions  of  the  Australasian  Institute  of  Mining  Engineers. 
Melbourne  and  Sydney. 

Trans.  Geol.  Soc.  S.A.  Transactions  of  the  Geological  Society  of  South  Africa.  Johannes- 
burg. 

Trans.  Inst.  Min.  Met.  Transactions  of  the  Institution  of  Mining  and  Metallurgy. 
London. 

Trans.  Inst.  M.E.  Transactions  of  the  Institution  of  Mining  Engineers.  Newcastle- 
upon-Tyne. 


PRINCIPAL    SERIALS    CITED  Xlll. 

Trans.  N.  Engl.  Inst.  Min.  cfc  Mech.  Eng.    Transactions  of  the  North  of  England  Institute 

of  Mining  and  Mechanical  Engineers.    Newcastle-upon-Tyne. 
Trans.  N.Z.  Inst.    Transactions  and  Proceedings  of  the  New  Zealand  Institute.  Wellington 

(N.Z.). 
Trans.  S.  A.  Phil.  Soc.    Transactions  of  the  South  African  Philosophical  Society.    Cape 

Town. 
Transvaal  Mines  Dep.,   Rep.,   Geol.   Surv.     Transvaal   Mines  Department.      Report  of 

the  Geological  Survey.     Pretoria. 
Verh.  deidsch.  wissensch.  Ver.  Santiago.   Verhandlungen  des  deutschen  wissenschaftlicher 

Vereins  zu  Santiago  de  Chile.     Valparaiso. 
Verh.   naturh.    Ver.   preuss.   Rheinl.     Verhandlungen  des  naturhistorischen  Vereins  der 

preussischen    Rheinlande,    Westfalens    und   des    Regierungs-Bezirks    Osnabriick. 

Bonn. 
Verh.  russ.-k.  min.  Gesellsch.     Verhandlungen  der  russisch-kaiserlichen  mineral ogisc hen 

Gesellschaft.      St.    Petersburg. 
Zeit.  angew.  Chem.    Zeitschrift  fur  angewandte  Chemie.     Leipzig. 
Zeit.  anorg.  Chem.     Zeitschrift  fur  anorganische  Chemie.     Hamburg  and  Leipzig. 
Zeit.  deutsch.  geol.  Gesellsch.    Zeitschrift  der  deutschen  geologischen  gesellschaft.    Berlii:. 
Zeit.  Berg-,  Hiitt.-  u.  Salinenw.     Zeitschrift  fiir  das  Berg-,  Hiitten-  und  Salinenwesen  im 

preussischen  Staate.     Berlin. 
Zeit.  fiir  Knjst.    Zeitschrift  fiir  Krystallographie  und  Mineralogie.     Leipzig. 
Zeit.  fiir  praht.  Geol.     Zeitschrift  fiir  praktische  Geologic     Berlin. 


CONTENTS 


Part    I. 

The  General  Relations  of  Auriferous  Deposits. 

page 
Introductory. — Condition  of  the  Interior  of  the  Earth,  Fissures  in 

the  Zone  of  Fracture,  Source  of  Underground  Waters, 
Circulation  of  Underground  Waters,  Filling  of  Fissures, 
Secondary  Enrichment 1 

Physical  and  Chemical  Characters  of  Gold. — Native  Gold,  Pure  Gold ; 
Native  Alloys  of  Gold  :  Electrum,  Maldonite,  Rhodite, 
Porpezite,  Amalgam 13 

Compounds  of  Gold. — Tellurides  of  Gold  :  Calaverite,  Sylvanite, 
Mullerine,  Krennerite,  Hessite,  Nagyagite  ;  Sulphides  of 
Gold,  Selenide  of  Gold,  Chloride  of  Gold,  Silicate  of  Gold, 
Colloidal  Gold,  Ionised  Gold  27 

Classification  of  Auriferous  Deposits. — Auriferous  Provinces 42 

Primary  Deposits. — Archaean  Group :  India,  Western  Australia, 

South  Africa,  Appalachian  Fields,  South  Dakota,  Brazil    . .         47 

Pre-Cambrian    Group  :     India,    Western    Australia,    South 

Africa,  North  America,  South  America 54 

Tertiary   Andesitic    Group :     North  America,   Mexico,    New 

Zealand,  Hungary 59 

Granodioritic    Group :     Western    North    America,    Eastern 

Australia,  Urals,  Other  Fields    67 

General  Considerations 76 

Secondary  Deposits. — Due  to  Chemical  Action  at  Depth,  Due  to 

Chemical  Action  at  the  Earth's  Surface 78 

Arising  from  Mechanical  Action ;  Placers,  Beach  Sands,  Deep 
Leads  ;  Range  in  Geological  Time  of  Placers,  Witwaters- 
rand,  South  Dakota,  Western  Australia 86 

Source  and  Transport  of  Gold. — Source  of  Gold,  Transport  of  Gold, 

Dispersion  of  Gold  in  Nature 100 

Deposition  and  Concentration  of  Gold. — Precipitants  of  Gold,  Con- 
centration of  Gold  in  Nature,  Secondary  Enrichment, 
Shoots      108 


Xvi.  CONTENTS 

Part   II. 

The  Geographical  Distribution  of  Gold. 

page 
Europe. — England,    Wales,    Scotland,    Ireland,    Portugal,    Spain. 

France,  Switzerland,  Italy,  Servia,  Turkey,  Greece,  Rou- 

mania,     Austria-Hungary,     Germany,    Norway,     Sweden, 

Russia      119 

Asia. — Siberia,  Asia  Minor,  Arabia,  Persia,  Baluchistan,  Afghanis- 
tan, Tibet,  Eastern  Turkestan,  India,  Ceylon,  Burma, 
China,  Manchuria,  Korea,  Japan,  Formosa,  French  Indo- 
China,  Siam,  Federated  Malay  States 210 

East  Indian  Archipelago  and  Polynesia. — Philippine  Islands,  Borneo, 

Dutch  East  Indies,  New  Guinea,  New  Caledonia,  Fiji 290 

Australasia. — New  Zealand  ;  Australia  :  Queensland,  New  South 
Wales,  Victoria,  Tasmania,  South  Australia,  Northern 
Territory,  Western  Australia 305 

Africa. — Morocco,  Algeria,  Tunis,  Tripoli,  Egypt,  British  Sudan, 
Eritrea,  Abyssinia,  Italian  Somaliland,  British  Somaliland, 
French  Guinea,  Liberia,  Ivory  Coast,  Gold  Coast,  Togoland, 
Cameroons  (Kamerun),  French  Congo,  Angola,  Congo  Free 
State,  British  East  Africa,  Uganda  Protectorate,  German 
East  Africa,  Nyassaland  Protectorate,  Madagascar,  Portu- 
guese East  Africa,  Rhodesia,  Bechuanaland  Protectorate, 
Transvaal,  Natal,  German  South-West  Africa,  Cape  Colony       407 

North  America. — Newfoundland  ;  Canada  :  Nova  Scotia,  New 
Brunswick,  Quebec,  Ontario,  British  Columbia,  Yukon 
Territory  ;  United  States  of  America  :  Alaska,  Washington, 
Oregon,  Calif  ornia,  Idaho,  Nevada,  Arizona,  Colorado,  Utah, 
Texas,  New  Mexico,  Montana,  Wyoming,  South  Dakota, 
Minnesota,  Maine,  New  Hampshire,  Vermont,  New  York, 
Maryland,  Virginia,  Southern  Appalachian  States 458 

Central  America  and  West  Indies. — Mexico,  Guatemala,  British 
Honduras,  Salvador,  Honduras,  Nicaragua,  Costa  Rica, 
Panama,  Cuba,  Haiti,  Jamaica,  Dutch  West  Indies     597 

South  America. — Colombia,  Ecuador,  Bolivia,  Peru,  Venezuela, 
British  Guiana,  Dutch  Guiana,  French  Guiana,  Brazil. 
Uruguay,  Argentina,  Chile 619 

Index  to  Subjects     665 

Geographical  Index 669 

Index  to  Authors  cited 685 


LIST    OF    PLATES. 


TO    FACE  PAGE 

Crystallized  Gold — The  Latrobe  Nugget Frontispiece 

I.     Crystallized  Gold    22 

II.     Polished  and  Etched  Sections  of  Gold  Nugget 84 

III.  British  Auriferous  Localities    136 

IV.  Val   de   Challant  and  Val  d'Anzasca,  Piedmont,  Italy  154 
V.     Placers  of  the  Imperial  Cabinet..  Chilka  River,  Siberia  220 

VI.     Panoramic  View  of  Kolar  Goldfield,  India 250 

VII.     Dharwar  Schists,  Sangli  ;    Ancient  Rock  Mortars  and 

Grinding  Stones,  Sangli,  India     256 

VIII.     Coromandel,  New  Zealand    308 

IX.     Open-Cut,    Waihi   Lode,    New   Zealand ;    Humphre}^ 

Gully  Beds,  Westland,  New  Zealand    318 

X.     Gold-dredging  Rivers,  New  Zealand    322 

XL     Charters  Towers,  Queensland   330 

XII.     Mount  Morgan,  Queensland 336 

XIII.  Anticlinal     Fold,     Castlemaine,     Victoria ;      Arltunga 

Goldfield,  Central  Australia     372 

XIV.  Kalgoorlie,    Western    Australia    404 

XV.     Views   of  Auriferous   Region,    Egyptian  Desert 408 

XVI.     Ancient  Egyptian  Quartz-crushing  Mills  412 

XVII.     Ashanti   Goldfields   Mines,   West   Africa;   Sheba  Gold 

Mines,  Barberton,  Transvaal   422 

XVIII.     Auriferous  Series,  Rhodesia  (Giant  Mines  of  Rhodesia)  430 

XIX.     Auriferous  Series,  Rhodesia  (Globe  and  Phoenix  Mine)  434 

XX.     Geological  Map  of  the  Southern  Transvaal    440 

XXI.     Johannesburg  from  the  North    446 

XXII.     Penhalonga  Gold  Mines,  Umtali  Goldfield,  Rhodesia  ; 

Glynn's  Lydenburg  Mine,  Transvaal 450 

XXIII.  Theta  Reef,  Clewer  Mine,  Pilgrim's  Rest,  Transvaal . .  452 

XXIV.  Mill  Creek,  Frankfort,  Transvaal 454 

XXV.  Williams     Creek,       Cariboo ;         Hydraulic      Sluicing, 

Cunningham  Creek,  Cariboo 474 

XXVI.  1,500    feet     Level,     Maryland   Vein,     Grass     Valley, 

California;  Vein  Quartz,  De  Lamar  Mine,  Idaho  508 


XV111. 

XXVII. 

XXVIII. 
XXIX. 

XXX. 

XXXI. 

XXXII. 

XXXIII. 

XXXIV. 

XXXV. 

XXXVI. 

XXXVII. 

XXXVIII. 


LIST    OF    PLATES. 

TO    FACE  PAGE 

Trade  Dollar  Mine,  Florida  Mountain ;     De  Lamar 

Mine  and  Mill,  South  Dakota 518 

Tonapah  and  Neighbourhood 530 

Bull  Hill,  from  Squaw  Mount ;    Cripple  Creek  from 

Gold  Hill,  Cripple  Creek,  Colorado 548 

Bassick     Hill     and    Mount     Tyndall ;      Silverton, 

Colorado   554 

Ophir  Pass  and  Potosi  Peak,  near  Telluride,  Colorado       556 

The  Camp  Bird  Mine,   Ouray,   Colorado    558 

Diabase  Dykes  and  Ore-bodies,  Haile  Mine,  South 

Carolina 592 

Panoramic  View  of  El  Oro,  Mexico 606 

Cana,  Darien  ;  Porce  Valley,  Antioquia,  Colombia  614 
Santa    Isabel    Mine,    Colombia ;     Portovelo    Mine, 

Zaruma,  Ecuador 624 

Auriferous  Aplite  Dyke,  and  General  View,   Omai, 

British  Guiana 638 

Panoramic    View    of    Morro    Velho    Mine,    Minas 

Geraes,  Brazil  652 


LIST    OF    ILLUSTRATIONS. 


FIGS.  PAGE 

1-  6     Simple  Forms  of  Gold  Crystals 14 

7-12    Forms  of  Crystallized  Gold 15 

13-23            Do.           do.           do 16 

24-34            Do.           do.           do 17 

35          Filamentary  Gold,  Caledonian  Mine,  New  Zealand 18 

36-38     Incipient  Crystallization  of  Gold,   Verespatak    19 

39-45    Forms  of  Crystallized  Gold    20 

46-48     Crystallized  Gold,   Coromandel,  New  Zealand    21 

49-57     Sylvanite  from  Nagyag  and  Offenbanya   30 

58-61     Krennerite  from  Nagyag  and  Cripple  Creek 33 

62-63     Hessite  from  Botes,   Hungary    34 

64  Nagyagite     36 

65  Sketch  Map  of  the  World,  showing  Distribution  of  the 

Principal  Auriferous  Provinces 46 

66  Shoot  of  Gold  at  Intersection  of  Quartz  Vein  and  Indicator, 

Ballarat    73 

67  Gravels  Deposited  by  a  Meandering  River 89 

68  Ideal  Section  of  Ancient  Deep  Leads   93 

69  Thin  Section  showing  Free  Gold  in  Diorite  from  Mashona- 

land 101 

70-71     Sections  showing  Relations  of  Gold,  Telluride-ore,   and 

Quartz 109 

72  Auriferous  Localities  in  Great  Britain  and  Ireland 120 

73  Geology  of   Auriferous   Area   of  .the   Mawddach   Valley, 

North  Wales    125 

74  Cross-section  of  La  Gardette  Lode,  Isere  Dep 149 

75  Auriferous  Occurrences  of  Piedmont,  Italy     153 

76  Generalised  Sketch  Map  of  the  Geology  of  the  Transyl- 

vanian  Auriferous  Region 170 

77-8      Sections  through  Botesiu  and  Vulkoj 175 

79  Ideal  Cross-section  through  Nagyag  Mountains 177 

80  Glauch  Veins,  Nagyag 178 

81  Enrichment  at  Junction  of  Veins,  Nagyag 179 

82  Glauch  Veins,  Valea  Mori 184 


XX.  LIST    OF 

FIGS.  PAGE 

83  Geological  Sketch  Map  of  the  "  Twelve  Apostles  "  Mine, 

Ruda,  Transylvania    185 

84  Geological  Sketch  Map  of  the  Southern  Urals 200 

85  Geological  Sketch  Map  of  the  Neighbourhood  of  Ekaterin- 

burg    201 

86  Plan  of  Veinlets  in  Beresite  Dykes,  Berezovsk 202 

87  Geological  Sketch  Map  of  the  Neighbourhood  of  Miassk . .  205 

88  Geological  Sketch  Map  of  Auriferous  Area,  Bokhara 212 

89  Sketch  Map  of  Tibet 232 

90  Dharwar  Schist  Bands  in  Southern  India    243 

91  Geological  Sketch  Map  of  the  Kolar  Field,  India    252 

92  "  Rolls  "  in  Champion  Reef,  Kolar,  India    253 

93  Workings,  Pitch  of  Shoots,  and  Basic  Dykes,  Mysore  Mine  254 

94  Geology  of  the  Gadag  Mines,  India 257 

95  Sketch  Map  of  Burma    264 

96  Ore-Shoots  in  Aplitic  Dyke,  Weihaiwei    272 

97  Geological  Map  of  Thames  Goldfield,  New  Zealand    310 

98  Geological  Sketch  Map  of  Waihi  Mine 313 

99  Vertical  Cross-section  through  Martha  Hill 314 

100         Cross-section,  Waihi  Mine,  showing  "  Blind  "  Lodes 315 

101-2     Section  and  Plan  of  Blue  Spur  Gravels,  Otago    322 

103  Geological  Sketch  Map  of  Charters  Towers  Goldfield 330 

104  Geological  Sketch  Map  of  Mount  Morgan  Mine   334 

105  Geological  Sketch  Plan  of  Gympie  Goldfield 338 

106  Part  of  Section  across  Gympie  Goldfield 339 

107  Auriferous  Lead  under  Desert  Sandstone,  Mount  Brown  . .  343 

108  Vertical  Section  through  Deep  Lead,  Kiandra    345 

109  Geological  Map  of  Hillgrove  Goldfield 347 

110-6     Plan  and  Sections  of  Mount  Boppy  Syncline    348 

117  Section  through  Big  Nugget  Hill,  Hargraves 351 

118  Plan  of  Lucknow  Goldfield 352 

119  Details  of  Occurrence  of  Ore-bodies,  Lucknow 353 

120  Sketch  Section  of  Yalwal  Goldfield 357 

121-2     Plan  and  Section  of  Reef,  Panbula  Goldfield 358 

123  Auriferous    Quartz    "  Floors "    in    Morning    Star    Dyke, 

Wood's  Point 362 

124  Sketch  Plan  of  Ballarat  Field    363 

125  Vertical  Section  of  Indicator,  Ballarat 365 

126  Vertical  Section  of  Metropolitan  Lode,  Ballarat 366 

127  Ideal  Section  showing  Main  Reef  Lines,  Bendigo 367 

128  True  Saddle  Reef,  Bendigo 368 


ILLUSTRATIONS.  XXI. 

FIGS.  PAGE 

129  False  Saddle  Reef,  Bendigo 369 

130  Cross-section  through  Lazarus  Mine,  Bendigo    370 

131  Section  of  Eastern  Portion,  Castlemaine  Goldfield 372 

132  The  Loddon,  Avoca,  and  Ballarat  Deep  Leads    374 

133-4     Sections  of  Victorian  Deep  Leads 376 

135-6     Geological  Plan  and  Section  of  Tasmania  Lode,  Beacons- 
field    380 

137  Section  through  New  Golden  Gate  Mine,  Mathinna    382 

138  Sketch  Map  of  Geology  of  Mount  Lyell    383 

139  Geological  Sketch  Map  of  Kalgoorlie    402 

140  Ore-bodies  in  Schisted  Band,  Lake  View  Consols 403 

141  Great  Boulder  Main  Lode,  Kalgoorlie 404 

142  Ancient  Egyptian  Mining  Map.  1300  b.c 409 

143  Geological  Sketch  Map  of  Northern  Atbai  Desert 411 

144  Geology  of  Manicaland  Auriferous  Area 428 

145  Geology  of  the  Witwatersrand,  near  Johannesburg    442 

1 46  Section  through  Syncline,  Witwatersrand  Beds    444 

147  Section  showing  Faulting  of  Main  Reef 445 

148  Enrichment,  Zwartkopje  Mine,  Barberton 449 

149  Diagrammatic    Section    across    the    Central    Lydenburg 

District      452 

150  Distribution  of  Auriferous  Series,  Nova  Scotia 460 

151  Diagrammatic    Section    across    Auriferous    Rocks,    Nova 

Scotia    462 

152  Roll  in  Nigger  Vein,  Tangier 463 

153  Crenulated  Quartz  Vein,  Moose  River  District 464 

154  Section  through  Lightning  Creek,  Cariboo 474 

155  Sketch  Map  showing  Geology  in  the  Vicinity  of  Klondike . .  481 

156-7     Ideal  Sections  across  Bonanza  Valley 485 

158-9     Geological  Plan  of  and  Section  through  Juneau,  Alaska    . .  497 

160  Section  across  Mother  Lode  at  Quartz  Mount 505 

161  Plan  of  Mother  Lode,  near  Coulterville   506 

162  Geological  Map  of  Grass  Valley  and  Nevada  City,  California  507 

163  Cross-section  of  Maryland  Vein  above  1,500ft.  level 508 

164  Auriferous  Gravel  buried  beneath  Lava,  Forest  Hill  Divide, 

American  River 510 

165  Plan  of  Blue  Lead  near  Mokelumne  Hill     511 

166  Cross-section    East    from    Mokelumne    River,     showing 

Ancient  River  Channels 512 

167  Geology  of  De  Lamar  Mine  and  Vicinity,  Idaho 517 


XXII.  LIST    OF 

FIGS.  PAGE 

168  Section  through  De  Lamar  Vein  System 518 

169  Geological  Map  of  Neighbourhood  of  the  Comstock  Lode, 

Nevada      521 

170  Formation  of  Bonanzas  in  Hanging  Wall,  Comstock  Lode . .  523 

171  Geological  Map  of  Tonopah  Goldfield 527 

172  Sketch  showing  Masking  of  Auriferous  Veins,  Tonopah ....  528 

173  Ideal  Section  across  Tonopah  Rocks 529 

174  Geological  Map  of  Goldfield,  Nevada 531 

175  Geological  Map  of  Ruby  Hill,  Eureka,  Nevada 534 

176  Cross-section  in  Phoenix  Mine,  Eureka 535 

177  Section  through  Florence  Mine,  Leadville    541 

178  Geological  Map  of  Bassick  Hill,  Colorado 542 

179  Geological  Section  through  Bassick  Mine 543 

180  Cross-section  through  Ore-body  of  Bassick  Mine 544 

181  Cross-section  of  Bull-Domingo  Chimney 544 

182  Geological  Map  of  the  Cripple  Creek  Goldfield,  Colorado. .  547 

183  Sections  in  North  Star  Mine,  Cripple  Creek 548 

184  Ore-streaks  in  Andesite-Breccia,  Cripple  Creek 549 

185  Sheeting  in  Breccia,  Portland  Mine,  Cripple  Creek 550 

186  Impregnations  along  Parallel  Fractures,  Cripple  Creek ... .  551 

187  Stereogram  of  Ore-shoot  on  the  Pinto  Dyke  and  Pharmacist 

Vein,  Cripple  Creek 552 

188  Section  through  Stratton's  Independence  Mine,  showing 

Granite-Breccia  Contact     553 

189  Geology  of  Camp  Bird  and  Neighbourhood 555 

189a      Vein-quartz,  Camp  Bird  Mine 556 

190  Geology  of  Telluride  and  Vicinity 558 

191  Diagrammatic  Section  through  Enterprise  Blanket,  Rico. .  559 

192  Section  through  Gold  and  Silver  Ledge,  Mercur,  Utah. .  . .  564 

193  Ore-deposit    at    Contact    of    Porphyry    and    Limestone, 

Maginnis  Mine,  Montana   573 

194  Geological  Map  of  the  Southern  Black  Hills,  South  Dakota  577 

195  Geological  Map  of  Neighbourhood  of  Lead  City,  South 

Dakota 579 

196  Star- Old  Abe  Section,  Homestake  Mine 580 

197  Section  through  Hawkeye-Pluma  Mine 581 

198  Geological  Section  from  Homestake  Mine  Eastward 582 

199-200     Sections    showing    Siliceous    Ore-shoots    in    Dolomite, 

Black  Hills 582 

201         Diagrammatic  Section  across  Lockhart  Vein,  Dahlonega  . .  590 


ILLUSTRATIONS.  XX111. 

FIGS.  PAGE 

202  Sketch  Map  showing  Principal  Ore-bodies,  Haile  Mine 592 

203  Vertical  Section  of  the  Beguelin  Ore-body,  Haile  Mine ....  593 

204  Ideal  Section  through  Pinitos  Range,  Magdalena  District, 

Sonora   601 

205  Guadalupe  y  Calvo     602 

206  Geological  Section  of  the  Lluvia  de  Oro  District 604 

207  Longitudinal  Section,  El  Oro  Mine 607 

208  Section  of  the  Espritu  Santo  Mine,  Cana 614 

209  Section  through  the  Quinua  Mine 631 

210  Map   of  Auriferous  Portion   of  Minas   Geraes   Province, 

Brazil     647 

211  Section  through  Ouro  Preto  Mountain 648 

212  Section  through  Passagem  Mine 648 

213  Plan  of  Passagem  Mine 651 


GOLD: 


ITS    GEOLOGICAL    OCCURRENCE    AND 
GEOGRAPHICAL   DISTRIBUTION. 


PART    I. 

The   General   Relations   of   Auriferous   Deposits. 

INTRODUCTORY. 

Before  entering  on  the  discussion  of  the  subject  proper,  it 
will  be  necessary  to  outline  certain  fundamental  premises  of  belief, 
and  incidentally  to  demand  certain  postulates  that  have,  from 
unchallenged  reiteration,  assumed  more  or  less  axiomatic  force 
but  which  are.  none  the  less,  mere  assumptions.  Than  the  logical 
instability  of  the  broad  hypotheses  upon  which  the  philosophical 
literature  relating  to  ore-deposits  is  based,  no  one  feature  is  brought 
more  prominently  into  relief  by  a  close  examination  of  the  subject, 
and  it  cannot  therefore  be  expected  that  the  special  section  hereafter 
to  be  treated  will  be  free  from  the  stigma  of  speculation  that  attaches 
to  the  whole.  Frequently  in  the  history  of  the  study  of  the  genesis 
of  ore-deposits  have  hypotheses  based  upon  isolated  reactions  in 
the  laboratory,  or  upon  imperfectly  correlated  observations  in  the 
field,  failed  in  their  broader  application  ;  and  though  it  is  certain 
that,  with  increase  of  chemical  knowledge,  and  by  the  multiplication 
of  observations  from  which  the  personal  factor  is  almost  totally 
eliminated,  there  will,  in  course  of  time,  .be  evolved  a  theory  which 
must  approximate  very  closely  to  the  truth,  yet  it  is  equally  certain 
that  the  speculative  element  which  now  bulks  so  largely  in  problems 
of  this  nature  will  never  be  entirely  absent,  so  long  as  man  is  unable 
to  reproduce  at  will  the  widely  varying  conditions,  or  to  regulate 
the  many  interdependent  reactions,  attendant  on  the  natural 
deposition  of  ores. 

Condition  of  the  Interior  of  the  Earth. — In  the  first  place, 
some  space  must  be  given  to  the  consideration  of  the  pro- 
bable condition  of  that  portion  of  the  earth's  bulk  which 
is  not  available  for  direct  observation.      It  is  unnecessary  at  the 


Z  INTRODUCTORY. 

present  moment  to  closely  examine  the  various  theories  put  forward 
from  time  to  time  as  explanatory  of  the  observed  phenomena,  but 
it  seems  clear  that  all  hypotheses  regarding  the  condition  of  the 
earth's  interior  must  be  based  on  three  main  premises  : — 

(a)  That  while  the  mean  density  of  the  thin  outer  shell  accessible 

to  our  observation  is  only  2«5,  the  density  of  the  earth 
as  a  whole  is  5  •  6  ; 

(b)  That  the  earth  is  a  rigid  body,  certainly  as  rigid  as  a  sphere 

of  glass  ;    and 

(c)  That  the  earth's  interior  is  very  highly  heated. 

And  though  the  last  is  at  best  only  an  inference,  yet  from  analogy 
with  other  celestial  bodies,  and  from  other  considerations,  there  seems 
no  possible  reason  for  refusing  to  admit  it  as  a  fundamental  premise. 

Taking  the  diameter  of  the  earth  as  8,000  miles,  and  assuming 
the  simplest  rate  of  increase  of  density,  viz.,  an  increase  directly 
proportional  to  the  depth,  we  find  from  mathematical  considerations 
that  the  zone  of  mean  density  (5-5)  will  be  reached  at  a  depth  of 
about  1,000  miles,  and  that  the  density  at  the  centre  may  be 
estimated  at  14-5.  With  other  rates  of  regular  progression,  the 
zone  of  mean  density  will  be  passed  at  much  greater  depths.  From 
considerations  of  temperature  and  pressure,  it  may  reasonably  be 
concluded  that  the  earth  from  its  surface  to  its  centre  may  be 
divided  into  three  zones  : — 

(a)  A  crust  solid  to  a  depth  of,  say,  25  miles. 

(b)  A  liquid  magma  highly  heated  and  under  great  pressure, 

extending  to  a  depth  of,  say,   200  miles. 

(c)  A  gaseous  magma  extending  to  the  centre,  the  high  viscosity 

and  relative   incompressibility  of  the  magma  rendering 
the  whole  as  rigid  as  steel. 

Of  the  last-mentioned  sphere  nothing  may  here  be  said.  It  lies 
even  beyond  the  domain  of  geological  speculation,  and  its  problems 
may  be  attacked  only  by  the  physicist.  Its  outer  portion  merges 
gradually  into  the  liquid  magma,  not  through  successive  concentric 
shells  of  substances  that  have  reached  their  critical  temperatures, 
but  rather  through  an  irregular  and  indefinite  mixture  of  gaseous 
and  liquid  constituents.  The  junction  between  the  centrosphere 
(the  barysphere  of  Posepny,  or  the  geite  of  Milne)  and  the  liquid 
magma  is  placed  at  about  200  miles,  on  the  assumption  that  the 
rate  of  increase  of  temperature  at  great  depths  is  identical  with 
that  observed  at  the  surface — an  assumption  for  or  against  which 
few  arguments  can  be  urged. 


THE  INTERIOR  OF  THE  EARTH.  3 

Between  the  liquid  magma  and  the  solid  crust  there  must 
likewise  lie  a  zone  of  transition,  in  which  some  of  the  mineral 
constituents  have  already  commenced  to  separate  out  from  the 
parent  magma.  It  is  not  probable  that  the  boundary  between 
the  solid  crust  and  the  liquid  magma  is  more  than  rudely  spherical 
in  form,  for  the  thickness  of  the  solid  crust  must  vary  considerably  ; 
its  lower  limit  approaching,  in  regions  of  extensive  vulcanicity,  much 
closer  to  the  earth's  surface  than  is  elsewhere  the  case.  From  this 
boundary  outwards  the  probable  condition  of  the  "'  crust  "  must 
be  dealt  with  in  detail,  for  it  is  in  this  outer  25  miles  of  the  earth's 
mass,  and  in  this  alone,  that  the  essential  operations  of  ore-deposition 
take  place.  If  this  be  granted,  and  there  seems  every  reason  to 
consider  the  postulate  at  least  justifiable,  it  follows  then  that,  in 
dealing  with  the  problems  afforded  by  ore-deposits,  the  whole  zone 
so  dealt  with  may  be  considered  to  be  precisely  similar  in  physical 
character  and  in  chemical  composition  to  that  with  which  we  are  more 
immediately  conversant.  For  since  it  has  already  been  assumed 
that  the  rise  in  density  with  increasing  depth  from  the  earth's 
surface  is,  in  all  probability,  regular,  and  at  1,000  miles  this  is  only 
from  2-5  to  5-5,  then  at  the  comparatively  insignificant  depth  of  25 
miles  the  increase  in  density  or  the  change  in  chemical  combination 
is  negligible. 

Following  Van  Hise"  in  principle,  two  main  divisions  of  the 
solid  crust  may  be  recognised,  according  to  the  manner  in  which 
the  rocks  of  each  division  adapt  themselves  to  the  varying  stresses 
induced  by  the  movements  of  the  crust  : — 

(a)  Zone  of  no  wage  :  This  is  the  zone  immediately  above  the 
liquid  magma  ;  here  the  rocks  yield  to  stress  by  differential  move- 
ments of  the  individual  particles,  each  accommodating  itself  to 
the  strain  by  a  fresh  disposition  of  its  dimensions  with  respect  to 
those  of  its  neighbours.  Small  though  the  individual  movement 
may  be  at  any  time,  the  aggregate  result  is  stupendous ;  its  degree 
is  occasionally  revealed  to  us  by  time  and  consequent  denudation. 
Since  the  pressure  in  this  zone  is  enormous, -it  follows  that  no  fissure 
can  exist,  for  the  mass  must  be  supposed  to  be  sufficiently  plastic 
to  flow,  and  so  to  close  any  fissure  formed  in  the  not  improbable 
event  of  a  sudden  shock,  as  of  a  movement  in  the  crust  above, 
momentarily  overcoming  the  cohesion  of  the  rock.  We  have  here 
in  the  upper  portions  of  the  zone,  as  Van  Hise  justly  points  out, 
the  fissures  of  the  overlying  zone  of  fracture  gradually  becoming 
narrower,  and  at  length  dying  out  in  depth. 

a  "  Principles  of  North  American  Pre-Cambrian  Geology,"  16th  Ann.  Rep.  U.S. 
Geol.  Surv.,  1894-5,  Pt.  I.  pp.  598  et  seq.  ;  "  Metamorphism  of  Rocks  and  Rock  Flowage,1' 
Bull.  Geol.  Soc.  Amer.,  IX,  1898,  pp.  295-313,  318-326;  "Some  Principles  controlling 
the  Deposition  of  Ores,"  Trans.  Amer.  Inst.  M.E.,  XXX,  1901,  p.  45. 


4  INTRODUCTORY. 

(b)  Zone  of  fracture  :  This  zone  lies  along  the  outer  solid  portion 
of  the  lithosphere.  Its  depth  must  be  extremely  variable,  its  lower 
surface  lying  approximately  parallel  to  the  boundary  of  the  liquid 
magma  and  ranging  from  near  the  surface  in  regions  of  extensive 
and  active  vulcanicity,  to  considerable  depths  in  regions  of  long 
continued  sedimentation.  Of  the  average  depth  of  the  zone  it  is 
impossible  to  say  much.  It  is  possibly  more  than  eight,  but  is 
probably  less  than  ten  miles.  In  this  zone,  as  the  name  signifies, 
the  solid  rocks  adapt  themselves  to  stress  by  fracturing  along  lines 
of  weakness,  thus  producing  in  the  strata  the  manifold  varia- 
tions observable  at  the  surface,  for  even  in  the  case  of  folded  rocks, 
the  convolutions  are  generally  produced  by  the  formation  of  numer- 
ous minute  parallel  faults.  A  limited  acquaintance  with  mining 
operations  is  generally  quite  sufficient  to  demonstrate  the  almost 
universal  prevalence  of  larger  faults. 

Van  Hise  raises  the  transition  rocks  between  these  two  zones 
to  the  dignity  of  a  third  zone  ;  but  inasmuch  as,  from  the  very 
nature  of  the  change,  there  cannot  be  found  any  salient  feature 
by  which  the  transition  belt  may  be  designated,  and  since  it  can 
be  described  only  by  more  or  less  negative  terms,  the  general 
statement  is  here  given  its  simplest  expression. 

Fissures  in  the  Zone  of  Fracture. — A  fissure  may  in  all  cases 
be  regarded  as  evidence  of  release  from  past  strain,  and  since 
stresses  may  be  of  indefinite  force,  act  through  indefinite 
time,  and  through  indefinite  space,  and  on  rocks  varying 
greatly  in  composition,  texture,  hardness,  and  toughness, 
we  may  expect  to  find,  and  do  find,  fissures  of  almost  infinite 
variety.  Further,  since  these  fissures  in  the  zone  of  fracture 
become  the  water  channels  of  the  surface  rocks,  and  since  percolating 
waters  and  their  dissolved  salts  act  with  more  or  less  effect — purely 
solvent  or  metasomatic  as  the  case  may  be — on  the  walls  of  the 
fissures,  the  form  of  these  and  the  nature  and  composition  of 
the  walls — two  of  the  features  which  have  been  relied  on  as 
classificatory — become  greatly  modified  if  not  completely  changed. 
It  will  therefore  be  apparent  that  any  genetic  classification — and  none 
other  is  scientific — of  these  fissures  (as  distinguished,  of  course,  from 
the  veins  which  are  afterwards  formed  in  them)  is  impossible. 

Classification  of  Ore  Deposits. — Classifications  of  ore-bodies 
based  on  the  form  of  the  filled  fissure  were  those  of  Whitney, a 
of    Pumpelly,6  of    J.  A.  Phillips,0    of   Louis,**  and   of   others.     As 

a"  Geol.  Surv.  of  the  Mississippi  Lead  Region,"  Albany,  1868,  p.  '224. 
b  "  Geol.  and  Mining  Industry  of  Leadville,"  Washington,  1886,  p.  373. 
c  "Treatise  on  Ore  Deposits,"  London,   18S6,  p.  3. 

^"Treatise  on  Ore  Deposits"  by  J.  A.  Phillips,  revised  by  H.  Louis,  2nd  Ed., 
London,  1896,  p.  10. 


FISSURE    VEINS.  5 

may  be  readily  seen,  the  distinction  between  "  fissure,"  '  bedded," 
l'  contact,"  and  "  gash  '  veins,  '  stockworks,"  and  "  massive  ' 
deposits  is  merely  one  of  degree  of  complication,  or  of 
chance  environment,  and  is  in  no  wise  related  to  the 
genesis  of  the  original  space  in  which  the  deposits  are  now 
found.  F.  Posepny"  appears  to  have  been  one  of  the  first 
to  clearly  recognise  this  fact,  for  he,  followed  afterwards  by  Monroe 
and  Kemp/'  suggested  a  more  or  less  genetic  classification,  dividing 
all  ore-deposits  into  those  formed  in  ;'  spaces  of  discission  "  and 
those  formed  in  "  spaces  of  dissolution."  The  differentiation  here, 
however,  is  not  real,  for  it  is  not  possible  to  conceive  of  a  "  space 
of  dissolution  '  in  a  soluble  rock  that  had  not  its  origin  and  its 
general  direction  determined  by  a  rock  fracture,  however  small. 
Since,  therefore,  it  must  be  admitted  that  the  form  of  a  fissure 
may  be  modified  indefinitely  by  percolating  waters,  it  follows  that 
''  spaces  of  dissolution,"  when  considered  genetically,  cannot  be 
separated  from  "  spaces  of  discission."  A  better  classification, 
and  certainly  at  first  sight  a  more  scientific,  is  that  of  Waldemar 
Lindgren.c  Here,  fissure-veins,  which  are,  in  effect,  any  form  of  a 
mineral  mass  filling  a  fissure,  are  classified  according  to  the  dis- 
tinctive metasomatic  processes  that  have  taken  place  within  the 
fissure.  From  a  genetic  point  of  view,  the  weakness  of  the  classifi- 
cation lies  in  the  fact  that  the  same  waters  may,  and  certainly  do, 
produce  different  results  in  different  rocks.  Owing,  however,  to  the 
general  insusceptibility  of  gold  to  the  solvent  action  of  the  percolating 
waters  that  so  readily  affect  the  country  walls,  and  to  the  fact  that 
the  gangue  of  an  auriferous  vein  is  most  often  quartz,  a  mineral 
even  less  susceptible  to  these  solutions  than  gold,  the  classification 
based  on  metasomatic  changes  loses  much  of  its  value  when  applied 
to  auriferous  veins.  Indeed,  our  knowledge  of  the  processes  of 
auriferous  deposition  is  much  too  scanty  to  admit  of  close  and 
particular  classifications,  which,  being  based  largely  upon  assump- 
tions presented  in  the  guise  of  fact,  are,  by  obscuring  the  real  issues, 
harmful  rather  than  beneficial.  Form,  position  and  associates  (the 
last  in  qualified  degree)  are  most  unreliable  classificatory  factors, 
and  yet  they  have  formed  the  basis  of  most  classifications  hitherto 
presented.  The  weakness  of  systems  dependent  on  the  two  first- 
named  has  already  been  indicated,  and  it  will  be  shown  later  that 
the  ions  of  gold  are  so  loosely  balanced  that  the  introduction  of 
almost  any  foreign  vagrant  ion  will  be  followed  by  the  aggregation 
and  deposition  of  the  gold.  This  treatise  is  therefore  largely  a  plea 
for  a  franker  confession  than  is  usual  of  ignorance  of  the  conditions 

a  Trans.  Amer.  Inst.  M.E.,  XXIII.  p.  197. 

b  "  The  Ore  Deposits  of  the  United  States,"  New  York,  1893,  p.  52. 
c  Trans.  Amer.  Inst.  M.E.,  Vol  XXX,  p.  578. 


6  INTRODUCTORY. 

of  auriferous  deposition,  and  for  the  adoption  of  a  classification 
that,  while  as  narrow  as  possible,  is  yet  no  narrower  than  is  justified 
by  our  actual  knowledge.  The  presence  of  fluorite  in  the  gold- 
telluride  deposits  of  Cripple  Creek  has  caused  Lindgren," 
to  create  a  separate  division  of  "  Fluorite-go  Id -tellurium 
veins,"  and  yet  there  is  nothing  either  in  the  present  writer's 
examination  of  that  region  or  in  the  literature  of  those  deposits 
to  show  that  the  presence  of  fluorite  is  not  purely  adventitious, 
that  it  has  had  any  effect  whatever  upon  the  deposition  of  the 
gold,  or  that  it  was  in  any  way  originally  in  genetic  connection.  On 
the  other  hand,  it  will  be  shown  later  that  Tertiary  andesites  of 
the  character  of  those  of  Cripple  Creek  furnish,  in  many  parts  of 
the  world,  veins  and  auriferous  associates  (with  the  exception  of 
fluorite)  similar  to  those  of  Cripple  Creek,  and  this  relation  has 
therefore  been  selected  as  the  narrowest  to  which,  in  the  given 
instance,  classificatory  value  may  be  attached. 

Source  of  Metallic  Ores. — An  ore-body  is  in  nearly  every 
case  the  result  of  long  continued  concentration,  generally  in  a  fissure 
or  permeable  belt  in  the  zone  of  fracture.  Ore-bodies  may  occur 
in  igneous  or  in  sedimentary  rocks  ;  but,  however  occurring,  the 
primary  source  of  the  metallic  ore  is  to  be  looked  for  in  igneous 
magmas,  through  which  the  heavy  metals  have  once  been  diffused, 
and  from  which  they  have  been  separated  :  (a)  by  magmatic 
differentiation,  (6)  by  the  leaching  action  of  percolating  solutions, 
or  (c)  by  the  mechanical  separation  effected  by  running  water 
during  the  process  of  denudation.  Analytical  research  by 
many  chemists b  has  shown  that  nearly  all  the  common 
metals,  including  gold,  are  to  be  found  in  the  igneous 
rocks,  both  plutonic  and  volcanic.  Harrison,  for  example, 
examining  the  igneous  and  metamorphic  rocks  of  British 
Guiana,  found  that  of  29  rocks  selected,  only  one  was  free  from 
traces  of  gold.  The  maximum  quantity  of  gold  obtained  was 
43  grains  per  ton  ;  the  mean  was  6  •  5  grains.  While  in  many  of  the 
cases  above  cited  it  is  possible,  and  in  some  cases  probable,  that 
the  metallic  content  was  introduced  by  wandering  solutions  after 
the  consolidation  of  the  magma,  there  yet  remains  sufficient  evidence 
to  fully  justify  the  assumption  that  the  great  bulk  of  the  metals 
of  the  crust  was  brought  within  reach  of  percolating  meteoric  waters 
or  of  denuding  agents  by  inclusion  within  upward-moving  magmas 

"  Trans.  Amer.  Inst.  M.E.,  XXX,  1900,  p.  578,  et  seq. 

''  Fore h hammer,  Pogg.  Annal.,  XCV,  p.  60 ;  Sandberger,  "  Untersuchungen  iiber 
Erzgange,"  Wiesbaden,  1885  ;  Becker,  Mon.  U.S.  Geol.  Surv.,  Ill,  1882,  p.  223;  Idem, 
op.  cit.,  XIII.  1S88.  P.  350;  Curtis,  op.  cit..  VII,  1884,  p.  80;  Robertson,  Bull.  Missouri 
Geol.  Surv.,  VII,  1894,  p.  479  ;  Harrison,  Rep.  Mines  Dep.  Brit,  Guiana,  1905  ;  Dieula- 
fait,  Ann.  chim.  physiq.,  XVIII,  1879,  p.  349  ;   and  by  many  others. 


SOURCE  OF  METALLIC  ORES.  7 

of  certainly  much  greater  density  than  those  highly  aqueous 
solutions  which  may,  with  reason,  be  deemed  to  form  a 
portion  of  the  more  tenuous  end-products  of  magmatic 
differentiation.  Of  the  nature  of  the  combination  of  the  metals 
or,  indeed  of  their  associates  or  hosts  within  the  magmatic  mass, 
nothing  may  be  said.  It  seems  reasonable  to  assume  that  authigenic 
metallic  ores  will  be  found  with  the  ferro-magnesian  silicates  or 
with  the  heavy  oxides  (magnetite,  rutile,  &c),  for  it  still  remains 
doubtful  whether  metallic  sulphide  minerals  may  be  regarded  as 
original  in  igneous  rocks.  In  the  majority  of  investi- 
gated cases  metallic  sulphides  have  certainly  been  intro- 
duced subsequently  to  the  consolidation  of  the  rocks  in  which 
they  are  found,  and,  notwithstanding  the  mass  of  evidence  adduced, 
for  example,  for  the  magmatic  hypothesis  of  origin  of  the  Sudbury 
sulphide-ores,"  there  are  many  authorities b  who  have  ascribed 
the  concentration  of  sulphide-ores  found  in  that  place  and  elsewhere 
to  deposition  from  circulating  aqueous  solutions.  In  whatever  form 
the  heavy  metals  may  be  combined,  their  percentage  of  the  total 
magmatic  mass  is  always  far  too  small  to  constitute  an  ore.  Iron 
alone  occurs  in  any  quantity,  its  average  percentage  in  igneous 
masses  being  estimated  at  4-46  only.c  Before  the  heavy  metals  can 
be  aggregated  in  sufficient  quantities  to  be  termed  ore-bodies,  they 
must  be  leached  or  washed  from  their  matrix  of  igneous  rock  and 
re-deposited  in  concentrated  form.  Assuming  for  the  moment 
that  magmatic  differentiation  is  of  dubious  efficiency  in  the 
concentration  of  ores,  the  universal  agent  of  solution  and  concen- 
tration is  therefore  the  water  that  is  always  in  motion  in  the 
fissures  and  crevices  of  the  solid  crust.  Except  in  the  case  of 
beach  iron-sands,  mechanical  concentration  by  running  or  moving 
waters  plays  little  part  in  the  formation  of  ore-bodies  from 
consolidated  igneous  rocks. 

Source  of  Underground  Waters. — Two,  and  only  two, 
sources  of  the  waters  which  traverse  the  fi'ssures  of  the  earth's  crust 
are  possible,  viz.,  (a)  magmatic,  and  (b)  meteoric  waters. 

Observers  who  have  noted  the  vast  quantities  of  steam 
accompanying  many  volcanic  eruptions  have  not  hesitated  to  claim 
for  the  liberated  water  vapours  an  origin  authigenic  with  that  of 
the  lavas  from  which  they  have  emanated,  a  view  that  of  recent 
years  has  met  with  very  wide  acceptance  among  Continental  and 
American    geologists.       The    arguments    for  this  view  have   been 

a  Walker,  Q.J.G.S.,  LIII,    1897.  p.  40;    Coleman,  Rep.    Ontario    Bureau    Mines, 
1905,  Pt,  III  ;   Barlow,  Econ.  Geol.,  I,  1906,  p.  454. 

b  Campbell  (W.)  and  Knight,  Eng.  Min.  Jour.,  LXXXII,  1906,  p.  909;      Dickson, 
Jour.  Can.  Min.  Inst.,  IX,  1906,  p.  239,  and  others. 

c  Clarke,  Bull.  U.S.  Geol.  Surv.,  No.  330,  1908,  p.  26. 


8  INTRODUCTORY. 

especially  well  presented  by  Professor  J.  F.  Kemp."  Much  stress 
is  laid  in  his  argument  on  the  fact  that  the  zones  of  deep  mining 
operations  show  the  rocks  to  be  comparatively  dry.  It  is  perfectly 
true  that  the  great  majority  of  mines  are  drier,  or  at  least  are  no 
wetter,  in  depth  than  near  the  surface,  and  many  more  instances 
than  those  cited  by  Professor  Kemp  may  be  adduced,  but  it  may 
not  therefore  be  assumed  that  all  strata  of  the  depths  quoted — 
2,000  to  5,000  feet — present  the  like  phenomenon.  The  deeper 
mines  of  Charters  Towers,  Queensland,  in  granite  and  tonalite, 
are  so  dry  at  depths  of  2,000  to  2,600  feet  that  water  for  drilling 
and  other  mining  purposes  is  sent  from  the  surface,  yet  in  the  same 
State,  an  artesian  well  in  sedimentary  strata  is  yielding  200.000 
gallons  water  per  diem  from  a  depth  of  5,045  feet,  and  some  wells, 
from  depths  of  over  4,000  feet,  have  outflows  of  1,000,000  gallons 
and  more  daily.  Again,  while  a  mine  may  be  "  dry  "  in  the  miner's 
sense,  or  may  even  be  dusty,  its  rocks  may  yet  contain  water.  In 
many  cases,  a  little  water  is  tapped  in  sinking,  representing  perhaps 
the  accumulation  of  years,  and  that  no  more  is  subsequently 
observed  is  due  to  the  fact  that  the  total  amount  furnished  by  the 
rock  fissures  is  dissipated  by  evaporation.  Too  little  regard  has 
been  paid  to  the  probability  of  the  chief  work  in  underground 
fissures  having  been  performed,  not  by  great  flows  of  wTater  circulating 
with  that  rapidity  which  implies  pumping  when  met  with  in  mines, 
but  rather  by  bodies  of  water  standing  in  closely-confined  spaces 
and  moving  with  almost  inconceivable  slowness.  But,  in  any 
case,  the  present  deficiency  of  waters  in  a  fissure  has  no  bearing 
whatever  on  the  origin  of  the  gangue  or  metalliferous  contents, 
and  is  indeed  as  little  an  argument  in  favour  of  an  origin  from 
magmatic  as  from  meteoric  waters  :  a  quartz-vein  merely  indicates 
that  at  the  period  of  its  formation  underground  waters  were  circu- 
lating. The  supply  of  siliceous  and  metalliferous  waters  may  have 
subsequently  been  cut  off,  or,  by  the  very  act  of  deposition,  the 
channels  may  have  been  closed,  in  either  case  giving  the  dry 
fissure  or  closed  vein  now  met  with.  While  not  denying  the 
possibility,  or  even  the  probability,  of  the  derivation  of  a  certain 
proportion  of  the  stock  of  underground  waters  from  a  magmatic 
source,  the  present  writer  is  inclined  to  ascribe  to  meteoric  waters 
nearly  all  metalliferous  deposits  of  economic  importance  ;  this 
premise  is  regarded  as  fundamental  in  the  speculations  that  are 
subsequently  offered.  The  magmatic  origin  claimed  by  Suess,  Weed, 
and  others,  for  the  waters  of  most  geysers  and  hot  springs  can 
certainly  not  be  granted,  for  it  has  been   shown h    that  the  great 


"  Trans.  Amer.  Inst.  M.E..  XXXI,  19(12,  pp.  169- IDS. 
Htaclaren,  Geol.  Mag.,  Dec.  V,  III,  190G,  p.  511. 


UNDERGROUND    WATERS.  9 

Waimangu  geyser,  in  the  Hot  Lakes  region  of  New  Zealand, 
depended  for  its  water  supply  on  a  superficial  source  ;  viz.,  on  the 
waters  of  an  adjacent  lake. 

Circulation  of  Underground  Waters. — The  motive  power 
inducing  the  circulation  of  meteoric  water  is  primarily  gravity, 
which  is  greatly  assisted  in  its  work  by  the  expansion  of  waters  due 
to  the  high  temperatures  encountered  in  depth.  This  deep  circu- 
lation has  been  compared  to  that  in  the  pipes  of  a  hot-water 
system  in  a  house,  but  though  the  simile  may  give  the  simplest 
expression  to  the  idea,  the  actual  circulation  must,  in  fact,  be 
extremely  complicated,  both  ascending  and  descending  currents 
receiving  contributions  from  sources  far  removed  from  each  other, 
and  dividing  often  to  travel  along  planes  differing  widely  in  direction 
and  in  extent.  At  great  depths  and  under  the  pressure  obtaining 
at  those  depths,  much  of  the  transference  of  water  is  probably 
effected  through  capillary  openings,  which  may  broadly  be  defined 
as  those  lesf,  than  -508  mm.,  if  circular,  and  -254  mm.  if  tabular, 
and  greater  than  -0002  and  -0001  mm.  respectively/'  In  any  case 
the  rate  of  percolation  at  great  depths  must  be  exceedingly  slow. 
Since  the  whole  case  for  the  assumption  of  a  deep  underground 
circulation  of  meteoric  waters  rests  on  hypothesis,  the  inferior  limit 
to  which  meteoric  waters  may  reach  cannot  be  indicated  with  any 
approach  to  accuracy,  but  it  may  reasonably  be  assumed  to  extend 
the  whole  depth  of  the  zone  of  fracture. 

A  clear  distinction  must  however  be  drawn  between  the 
deep  underground  circulation  above  referred  to  and  that  shallow 
surface  circulation  which  is  indicated  by  springs  and  by  the  waters 
of  perennial  streams.  The  latter  moves  in  a  zone  that  is  alternately 
wet  and  dry,  or  that  is  filled  with  surface  waters  moving  towards 
the  lowest  drainage  exit  of  the  surrounding  country.  Ordinarily, 
the  region  of  shallow  surface  circulation  (the  '  vadose  '  region 
of  Posepny)  does  not  descend  much  below  the  normal  drainage 
level,  but  in  special  cases,  as  in  an  artesian  basin  or  in  a  region 
of  springs  owing  their  origin  to  conditions  approximating  to 
those  necessary  for  an  artesian  system,  or  in  arid  desert  regions 
that  upon  occasions  receive  a  rain-fall,  surface  vadose  waters 
may  reach  great  depths. 

Filling  of  Fissures. — It  may  be  stated  as  a  general  law  that 
increase  in  temperature  or  in  pressure  increases  the  solvent  power 
of  a  liquid.  It  will  therefore  be  apparent  that  as  meteoric  waters 
descend,  their  action  on  the  metallic  salts  with  which  they  come  in 
contact   is  intensified  pari  passu  with  the  depth  to  which   they 


Slichter,  19th  Ann.  Rep.  U.S.  Geo!.  Surv.,  Pt.  II,  p.  317. 


10  INTRODUCTORY. 

penetrate.  The  metallic  salts  on  which  they  act  may  be  those 
already  deposited  in  the  waterways,  or  may  be  those  contained 
in  the  adjacent  walls  of  "country,"  and  the  breadth  of  the  water 
channel  is  here  considered  to  be  co-terminous  with  the  extent  of  the 
lateral  penetration  of  the  circulating  waters  from  the  fissure.  So 
much,  therefore,  of  the  original  restricted  lateral  secretion  theory 
may  be  admitted,  viz.,  that  percolating  waters  may  gain  their 
metallic  contents  from  the  rocks  immediately  contiguous  to  the 
fissures  through  which  they  are  passing.  That  they  must  deposit 
ore  in  those  fissures  cannot,  as  was  originally  demanded,  be  generally 
conceded. 

In  addition  to  the  above  supplies  of  metallic  salts  for  vein- 
filling,  there  must  be  admitted  another,  viz.,  that  yielded  to  meteoric 
waters  by  metalliferous  vapours,  potential  or  actual,  which  are 
assumed  to  be  a  possible  result  of  magmatic  differentiation.  These 
vapours  are  generally,  but  not  always,  incorporated  with  the 
meteoric  waters  at  great  depths.  Magmas  may  cool  at  comparatively 
shallow  depths,  and  indeed,  some,  as  we  know,  are  so  close  to  the 
surface  that  they  are  enabled  to  extrude  a  portion  of  their  bulk, 
unattended  by  any  seismic  phenomena  such  as  would  indicate 
forcible  expulsion  from  a  considerable  depth.  It  is  these  solutions 
containing  uprising  magmatic  vapours  that  furnish  the  essence  of 
the  original  ascension  theory. 

These  three  sources  of  supply — already-formed  fissure 
deposits  and  metasomatic  replacements  of  country,  authigenic 
deposits  in  igneous  rocks  or  in  sediments,  and  magmatic 
vapours  (in  reality  they  are  but  one,  for  all  have  been 
derived  primarily  from  igneous  magmas) — then,  furnish  the  ores 
of  metalliferous  veins.  To  the  last  mentioned,  the  writer  is 
inclined,  as  already  stated,  to  grant  a  subordinate  position, 
holding  that,  though  in  this  case  we  are  dealing  with  a  vera  causa, 
and  though  the  igneous  rocks  are  certainly  to  be  considered  as  the 
primary  source  of  the  earth's  accessible  ores,  yet  the  metallic 
content  of  the  igneous  rocks  has  been  yielded  after  rather  than 
before  their  consolidation,  and,  indeed,  is  the  result  of  leaching 
by  magmatic  aqueous  vapours  or  magmatic  waters  rather  than 
of  differentiation.  No  one  source  may,  therefore,  be  postulated 
for  any  given  ore  in  a  fissure.  We  see  that  the  component 
parts  of  a  single  crystal  of  a  homogenous  mineral  may 
have  been  derived  from  a  previously  existent  vein  crystal, 
from  a  rolled  fragment  in  a  sedimentary  rock,  from  an  authigenic 
crystal  in  an  igneous  rock,  and  from  vapours  arising  from  magmatic 
differentiation. 


SECONDARY    ENRICHMENT.  11 

Broadly  speaking,  the  ores  filling  fissures  (as  distinguished  from 
the  gangue)  may  be  divided  into  two  great  divisions,  according  to 
the  chemical  character  of  the  water  of  transportation.  Below 
the  ground-,  or  permanent,  water-level,  where  waters  are  hot 
and  alkaline,  sulphides  and  tellurides  are  deposited,  and  are  charac- 
teristic of  that  zone.  In  the  upper  or  vadose  zone,  waters  are  cold 
and  acid,  and  sulphides  and  kindred  salts  are  decomposed,  with  end- 
products  of  metals,  oxides,  certain  silicates,  and  sulphates.  These 
products,  and  especially  the  last  mentioned,  are  not  of  necessity 
deposited  in  the  vadose  zone,  but  may  under  given  conditions 
pass  downwards  to  the  ground-water  level  and  there  be  re-precipi- 
tated as  sulphides.  The  geological  agent  promoting  this  change  is 
denudation,  which,  by  locally  lowering  the  earth's  surface,  slowly 
lowers  the  ground-water  level,  thus  continually  exposing  the  top 
of  the  sulphide  zone  to  the  play  of  oxidising  waters. 

Secondary  Enrichment. — It  has  been  seen  that,  within  the 
mass  of  igneous  rocks,  metals  are  too  widely  diffused  to  furnish  ores, 
at  least  of  the  heavier  metals.  Nor  when  the  metals  are  leached  out 
and  deposited  in  the  fissures  of  the  deeper  circulation  are  they  generally 
in  a  state  of  sufficient  aggregation  to  furnish  ores.  Exceptions  to 
this  rule  do  occur,  and  are  far  more  numerous  than  would  be 
supposed  from  a  perusal  of  the  recent  literature  of  ore-deposits. 
Nevertheless,  most  ore-bodies,  and  certainly  nearly  all  in  the  upper 
portions  of  vein-fissures  or  ore-channels ,  owe  a  large  proportion  of  their 
economic  value  to  repeated  accretions  of  ore  or  to  repeated  subtractions 
of  gangue.  This  phenomenon  is  termed  "secondary  enrichment"  ; 
but  the  term  is  restricted  in  use  to  vein  and  other  deposits 
in  rock,  and  does  not  cover  those  concentrations  resulting  from  the 
sorting  action  of  running  waters,  as  in  the  case  of  gold  placers. 
Secondary  enrichment  may  be  positive  or  relative  :  it  may  result 
from  the  actual  addition  of  metallic  matter  or  from  the  removal 
of  base  matter,  the  total  quantity  of  metal  present  being,  in  the 
latter  case,  unaffected.  It  may  take  place  in  the  vadose  zone  or  in 
the  sulphide  zone.  In  the  former,  relative  enrichment  is  more  common 
than  in  the  latter.  In  the  former  also,  growth  by  simple  mass-action 
is  prevalent.  Thus  metals,  oxides,  silicates,  and  sulphates  are  drawn 
from  passing  solutions  and  added  to  the  already-deposited  metal 
or  salt.  Enrichment  below  the  ground-water  level  normally  takes 
place  by  the  reducing  action  of  unaltered  sulphide  minerals  on 
sulphate  solutions  moving  downward  from  the  vadose  zone.  There 
is  thus  formed  at,  or  somewhat  below,  the  ground-water  level, 
a  zone  of  sulphide  enrichment,  and  as  the  ground-water  level 
is  continually  being  lowered,  and  the  accumulated  mineral  of  many 
hundred  of  feet  of  vein  originally  overlying  is  there  being  deposited 


12  INTRODUCTORY. 

and  re-deposited,  notable  ore-bodies  may  result/'  From  the 
chemical  analogies  of  the  tellurides  and  sulphides,  a  similar  hori- 
zontal zone  of  telluride  enrichment  may  be  expected  in  gold- 
telluride  veins,  and  indeed  is  indicated  by  the  mining  experience 
gained  in  working  the  telluride  ores  of  Kalgoorlie,  Western  Australia. 
The  question  of  secondary  enrichment  being  one  of  the  highest 
importance  in  the  consideration  of  auriferous  deposits,  further 
attention  will  be  given  to  the  subject  in  a  later  section. 


a  Weed,  Bull.  Geol.  Soc.  Amer.,XI,  1899,  p.  179;  Idem.  Trans.  Amer.  Inst.  M.E., 
XXX,  1900,  p.  424;  XXXIII,  1903,  p.  747;  Emmons  (S.  F.),  ib.,  p.  177. 


J  3 


THE    PHYSICAL   AND    CHEMICAL    CHARACTERS 

OF  GOLD. 


Native  Gold. — Gold  is  very  widely  diffused  in  nature.  It  is 
found  native  in  irregular  masses,  strings,  scales,  plates,  and  crystals, 
in  quartz  or  sulphide  veins,  or  as  impregnations  in  the  country 
adjacent  to  fissures.  In  alluvial  gravels  it  occurs  as  scales,  grains, 
slugs,  and  nuggets  (pepites,  Fr.).  Regarded  broadly,  it  rarely 
shows  crystalline  form,  but  where  the  conditions  are  favourable, 
as  in  cavities  in  the  upper  or  vadose  zones  of  fissures,  or  in  loose 
permeable  alluvial  gravels,  where  expansion  is  not  hindered  by 
lack  of  space,  and  where  the  directive  lines  of  growth  are  not  deter- 
mined by  the  shape  of  a  cavity,  or  by  the  concurrent  growth  of 
another  mineral,  as  calcite  or  serpentine,  gold  obeys  the  natural 
laws  of  its  crystal  growth  and  crystallizes  in  various  isometric 
(cubic)  forms.  The  largest  and  most  perfect  crystals  are  always 
those  derived  from  alluvial  gravels,  since  there  the  growing  crystal 
has  apparently  often  been  able  to  accrete  with  equal  facility  matter 
from  all  sides.  Gold-crystals  from  placer  deposits  may  attain  a 
length  of  from  U  to  2  inches,  in  which  cases  they  are  nearly  always 
octahedra.  The  most  perfect  crystals  have  been  derived  from 
the  gravels  of  Victoria,  Australia.  Large  crystals,  especially  when 
octahedral,  often  possess  deeply  recessed  faces  and  salient  edges, 
indicating  either  a  comparatively  high  local  concentration  of  gold  in 
the  surrounding  solution,  or,  more  probably,  a  rapid  replenishment 
of  its  gold  content  at  the  time  of  growth  (Fig.  7).  Recessed  faces 
further  indicate  the  absence,  in  the  immediate  vicinity  of  the  crystal, 
of  solutions  that  have  only  just  passed  the  point  of  saturation, 
since  the  normal  Avork  of  these  in  crystal  growth  is  to  reduce  the 
inequalities  arising  from  irregularity  in  concentration  or  in  supply 
of  gold  from  solution.  The  concentration  necessary  to  secure  growth 
of  gold-crystals  does  not  prevail  throughout  the  whole  mass  of 
solution  in  the  gravel  or  in  the  vein-fissure,  but  is  to  be  regarded  as 
obtaining  solely  in  the  immediate  neighbourhood  of  already 
deposited  gold  and  to  arise  from  the  action  of  inherent  forces  of 
growth.  The  salient  edges  of  alluvial  gold-crystals  are  often  quite 
sharp,  presenting  thus  evidence  of  the  absence  of  agents  of  attrition 
or  of  solution.  The  presence  of  large  gold-crystals  in  alluvial  drifts, 
together  with  the  unworn  edges  often  shown  by  them,  is  largely 
relied  upon,  as  will  be  seen  later,  to  support  the  hypothesis  of  the 
growth    of    gold    in    situ    in    alluvial    deposits.      Liversidge"    has 

"Jour.  Chem.  Soc,  LXXXI,  1897,  pp.  1,  125. 


14 


CHARACTERS    OF    GOLD. 


shown  that  polished  and  etched  sections  of  rounded  and  water- 
worn  alluvial  nuggets  almost  invariably  show  them  to  possess 
an  internal  crystalline  structure.  A  rare  development  in  the 
crystallization  of  gold  is  shown  in  the  formation  of  blister-like 
protuberances  on  the  octahedral  faces  of  a  specimen  from 
California  (Plate  I).  These  are  not  capable  of  a  ready  ex- 
planation, since  they  do  not  appear  to  be  comparable  to  ordinary 
curved  faces,  which  are  often  to  be  referred  to  the  action  of  sol- 
vents, which  normally  work  by  first  attacking  the  crystal  edges. 
The  gold-crystals  of  the  vadose  zone  of  fissures  are  on  the  whole 


1. 


2. 


3. 


4. 


5. 


6. 


Figs.  1-6.     Simple  Forms  of  Gold  Crystals  (rarely  obtained  in  nature). 

Fig.  1.  Cube.     Fig.  2.  Octahedron.     Fig.  3.  Rhombic  dodecahedron.     Fig.  4.  Four-faced  Cube- 
Fig.  5.  Trapezohedron.     Fig.  6.  Six -faced  octahedron. 

much  smaller,  much  less  perfect,  and  much  more  complex  in  aggre- 
gation than  those  of  the  alluvial  drifts.  This  difference  is  probably 
due  largely  to  environment  and,  possibly,  to  differing  degrees  of 
concentration  of  auriferous  solutions,  since,  chemically  regarded, 
there  cannot  be  conceived  to  exist  any  radical  difference  between 
waters  percolating  in  the  upper  portions  of  fissures  above  the 
permanent  water-level  and  those  passing  through  placer  gravels. 
At  times  the  degree  of  auriferous  concentration  in  the  waters 
of  vein-fissures  must  be  relatively  high,  in  which  case  rapid 
deposition   is  expressed  by  the   formation  of  moss-  and  leaf -gold. 


CRYSTALLIZED    GOLD. 


15 


The  gold  of  quartz-veins  is  often  so  fine  as  to  escape  ordinary 
observation.  Edmana  has  shown  that  particles  of  gold  may  be 
less  than  '002  mm.  in  length.  When  extremely  fine  particles  of 
gold  are  dispersed  through  quartz  the  whole  acquires  a  greenish 
hue,  a  feature  which  is  most  distinctly  observable  perhaps  in 
specimens  from  the   free-gold  zones  of   andesitic  regions. 

The  crystal  forms  of  gold  hitherto  observed  have  been  the  cube 

,100 }  ;   rhombic  dodecahedron    ,110 J  ;   octahedron    -111-  ;   tetra- 

hexahedra  (four-faced   cubes)  {410},  {310},  1520},  {210}  ;  trapezo- 

hedra  ]  811 } ,  { 411  } ,  { 311 } ,   { 211 }  ;    and    hexoctahedra    (sLx-faced 

octahedra)     {421},     {321},     {543},    { 18.10.1  }.6        Ideally     simple 


10 


Figs.  7-12.     Forms  of  Crystallized  Gold. 

Figs.  7  and  8.  California.     Fig.  9.  Urals.     Fig.  10.  Boicza.     Figs.  11  and  12.  California. 

a={l(X)},  o=  { 1 1 1 } .  e*={ll0},  m={31l},  x=  {l8.10.l}. 

forms  are  rare.  Abnormal  forms  observed  in  gold  crystals 
have  at  times  been  ascribed  to  inclined  hemihedrism,  but 
there  is  no  sound  evidence  for  this  assumption,  and  gold  in 
crystallization  may  be  regarded  as  always  holosymmetric.  The 
crystallization  of  gold,  and  particularly  of  specimens  from 
Transylvania,  from  the  Urals,  and  from  Western  North  America, 
has   been   closely   studied   by   Rose,c    Helmhacker/    vom   Rath,' 


a  "  L'Or  dans  la  Nature,"  Cumenge  and  Robellaz,  Paris,  1897,  p.  40. 

"  This  form  has  been  determined  as  { 15.9.1 }  by  Naumann  and  as  { 19.11.1  }  by  Rose. 

cPogg.  Annal.,  XXIII,  1831,  p.  196. 


dMin.  Mittheil.,  1877,  App.  No.  1. 
eZeit.  fur  Kryst.,  I,  1877,  p.  1. 


16 


CHARACTERS    OF    GOLD. 


Figs.  13-23.     Forms  of  Crystallized  Gold.  Syseetsk,  Urals  (ddmhacker) 


CRYSTALLIZED    GOLD. 


17 


B 


Figs.  24-34.     Forms  of  Crystallized  Gold,  Sysertsk.  Urals  {Helmhacker). 


18 


CHARACTERS    OF    GOLD. 


Werner,"  Dana  (E.S.),  and  others. h  Considerable  aberration  from 
the  ideal  forms  of  isometric  symmetry  is  general,  as  will  be  seen 
from  an  inspection  of  the  accompanying  figures.  Abnormal  forms 
are  to  be  explained  by  simple  or  compound  twinning  parallel  to 
the  octahedron  or  by  elongation  or  flattening  along  a  di-trigonal 
axis  of  symmetry  (a  cube  diagonal),  and  one,  therefore,  normal  to 
faces  of  the  octahedron.  Twinning  and  elongation  may  produce 
rhombohedra.     The  form  shown  in  Fig.   45  is  apparently  a  com- 


Gvld>  ITtreads  magnified, 
ta  shenv  sha/fT/  characfv/: 


Fig.  35.     Filamentary  Gold  in  Quaktz  Vugh,  Caledonian  Mine,  New  Zealand  (Ward). 

About  i  natural  size 

bination  of  three  separate  rhombic  prisms  (with  angles  of  70°  32') 
terminated  in  each  case  by  pyramid  faces.  In  reality  each  branch 
is  a  combination  of  two  elongated  cubes  (a)  twinned  along  an 
octahedral  plane  and  terminated  by  faces  of  the  tetrahexahedron 
(e),  in  this  case,  { 210}.    The  faces  of  the  cube  are  further  striated 


aNeues  Jahrb.  fur  Min.,  I,  1881,  p.  1. 
6  Am.  Jour.  Sci.,  XXXII,  1886,  p.  132. 


CRYSTALLIZED    GOLD. 


19 


parallel  to  their  intersections  with  the  faces  of  the  terminating 
tetrahexahedron,  indicating  probably  successive  stages  of  parallel 
growth.  On  the  other  hand,  flattening  along  an  axis  normal  to  the 
octahedral  face  may  produce  forms  that  simulate  very  closely 
monoclinic  plates.  (Figs.  46  and  47.)  Other  faces  beside  those  of 
the  cube  may  be  striated.  Lewis"  has  noted  deep  striations  on 
the  faces  of  the  trapezohedron  |811[  parallel  to  their  line  of  inter- 
section with  the  faces  of  the  cube. 

Moss-gold,  wire-gold,  and  dendritic  forms  may  ordinarily  be 
taken  to  indicate  incipient  crystallization  along  di-trigonal  axes 
of  symmetry,  accompanied  by  abnormal  elongation  along  those 
axes.  In  some  cases,  as  in  the  wire-gold  from  the  Santa  Isabel 
mines  of  Colombia,   elongation  is  accompanied  by  twinning.     A 


Figs.  36-38.     Incipient  Crystallization  of  Gold,  Verespatak  (Vom  Rath). 


JlOO},  o={lll}. 


remarkable  form  of  moss-gold  is  shown  in  Fig.  35  from  the  formerly 
famous  Caledonian  mine,  Thames,  New  Zealand.  The  whole  grew  in 
a  cavity  lined  with  quartz  crystals.  The  filaments  were  sufficiently 
strong  and  sufficiently  interlaced  to  maintain  an  upright  position. 
They  were,  curiously  enough,  terminated  by  well-defined  crystals  of 
chalcopyrite,  crystals  of  which  were  also  attached  like  buds  to  other 
parts  of  the  threads. h  Filaments  of  gold  simulating  moss-  and 
tree-gold  have  been  produced  by  Liversidge  c  by  roasting  auriferous 
mispickel,  but  it  is  nevertheless  extremely  improbable  that    any 


a  Phil.  Mag.,  Ill,  1877,  p.  456. 

b  Ward,  Min.  Mag.,  Ill,  1879,  p.  81. 

c  Proc.  Roy.  Soc.  N.S.W.,  XXVII,  1893,  p.  1. 


20 


CHARACTERS    OF    GOLD. 


natural  filamentary  gold  has  been  deposited  otherwise  than  from 
aqueous  solution.  Gold  occasionally  shows  crystalline  skeletal 
growth  as  parallel  octahedra  united  on  octahedral  faces.     Much 


39 


40 


42 


43 


Figs.  39-45.     Forms  of  Crystallized  Gold. 

Figs.  39  and  40.  Oregon    (Dana).      Fig.  41.  Vercspatak,  Transylvania    (Vom    Rath). 

Fig.  42.  Vercspatak  (Werner).      Fig.  43.  Twin-crystals,  Verespatak  (Vom  Rath). 
Fig.   44.    Berezovsk,   Urals  (Fletcher).       Fig.  45.  Tvvin-crystals,  Zdraholcz  (Vom  Rath). 

o={lll},  a={l00},  d={  HO},  w={31l},  e={210},  /={310J-,  ^={411}. 

mote  rarely  does  it  occur  as  successive  cubes  disposed  along  an 
axis  of  di-trigonal  symmetry.  The  last  form  is  common  enough 
for  skeletal  growths  of  native  silver,  as  from  Kongsberg,  Norway, 


CRYSTALLIZED    GOLD. 


21 


but  has  been  noted,  by  the  present  writer  at  least,  only  in  a  few 
specimens,  of  which  one  of  the  most  perfect,  from  an 
unknown  locality,  is  in  the  Cambridge  University  Mineralogical 
Museum.  Indications  of  the  same  form  of  growth  may  also  be 
observed  in  the  La  Trobe  nugget,  figured  in  the  frontispiece  of 
this  volume. 

The  percentage  of  silver  admixed  with  gold  appears  to  exercise 
but  little  influence  on  crystallization,  as  might  indeed  be  inferred 
from  the  isometric  symmetry  of  native  silver.  Nevertheless  there 
are  some  grounds  for  a  suggestion  that  the  tendency  of  the  purer 
gold  is  to  adopt  the  simpler  forms  (octahedra  and  cubes)  in  crystal- 
lizing   rather    than    the    trapezohedra,    hexoctahedra,    &c,    found 


46 


47 


Figs.  46-48.     Crystallized  Gold,  Haurakt  Associated  Mine,  Coromandel  {Maclaren). 
Figs.  46  and  47.  Opposite  sides  of  same  plate,  X  1  J.     Fig.  48.  X  6. 


(ill  '-• 


llOJ;  m-m=\m  11 } 


most  commonly  in  electrurn  or  low-grade  "  gold."  The  problem 
is,  however,  complicated  by  the  fact  that  crystals  of  the  purer 
gold  are,  as  a  rule,  found  in  alluvial  gravels,  while  those  of  electrurn 
(native  gold-silver  alloy)  are  derived  from  fissures  in  the  vadose 
zones.  The  distinction,  such  as  it  is,  may  therefore  arise  from 
accompanying  physical  conditions,  and  not  from  inherent  properties 
of  gold  and  of  gold-silver  alloy  respectively. 

Even  the  purest  native  gold  contains  some  silver.  The  finest 
gold  yet  recorded  is  that  from  the  Great  Boulder  mine,  Kalgoorlie, 
Western  Australia.  It  was  obviously  derived  from  the  decomposition 
of  auriferous  tellurides  and  was  999-1  fine.  A  small  quantity 
of  gold  from  the  Pike's  Peak  mine,  Cripple  Creek,  Colorado,  showed 
on  assay  a  fineness  of  999,  while  a  very  large  portion  of  the  outcrop 


22  CHARACTERS    OF    GOLD. 

gold  of  the  famous  Mount  Morgan  mine,  Queensland,  was  997  fine.a 
The  last  has  furnished  probably  the  greatest  bulk  of  fine  gold, 
for  the  two  first-mentioned  results  were  obtained  from  assays 
of  small  picked  samples,  rather  than  from  the  mass  of  the  gold 
recovered  on  a  commercial  scale. 

Alluvial  gold  directly  derived  from  the  degradation  of  auriferous 
veins  is  invariably  higher  in  quality  than  the  gold  of  the  parent 
vein,  since  meteoric  waters. act  on  all  sides  of  the  liberated  grains 
and  particles,  and  remove  much  of  the  more  soluble  silver.  It  is 
c6mmonly  noted  that  alluvial  gold-dust  from  the  lower  reaches 
of  any  given  river  is  much  higher  in  quality  than  the  coarser  grains 
and  nuggets  of  gold  found  in  the  upper  waters  of  the  same  stream, 
the  increase  in  purity  arising,  of  course,  from  the  greater  total 
surface  exposed,  in  the  case  of  the  finer  dust,  to  the  action  of  silver 
solvents. 

Pure  Gold — Pure  gold  is  a  clear  yellow  metal,  unaffected 
by  the  atmosphere  or  by  its  contained  impurities.  The  colour  may 
be  varied  considerably  by  alloy  with  other  metals,  admixture  with 
copper  producing  a  reddish  tinge,  while  a  certain  percentage  of 
silver,  notably  15  per  cent,  according  to  Leach, h  yields  a  distinctly 
green  colour.  Finely-divided  gold  is  purple  by  reflected  and  green 
by  transmitted  light.  The  metal  is  exceedingly  malleable.  Its 
density  when  perfectly  pure  and  when  in  ingots  reaches  19-3  at 
70°  C,  but  this  density  is.  of  course,  never  attained  in  nature. 
According  to  Kahlbaum  and  Sturm c  the  density  of  soft  gold  is 
19-2601 ;  and  of  hard-hammered  gold,  19-2504.  The  melting  point 
of  gold  is  in  the  neighbourhood  of  1,064°  C.  The  following 
temperatures  have  been  arrived  at  experimentally  :  1,061° 
(Callendar),  1.061°  (Heycock  and  Neville),  1,064-3°  (Holborn 
and  Day),  1,065-6°  (D.  Berthelot),  1,067-4°  (Jacquerod  and 
Perrot).  When  molten,  gold  appears  to  take  on  a  greenish 
tinge.  It  may  be  readily  volatilised  in  the  electric  furnace. 
With  a  current  of  350  amperes  at  110  volts  no  less  than  60 
grammes  (nearly  2  ounces)  were  volatilised  in  6  minutes. 
With  a  current  of  the  same  voltage  but  of  500  amperes  13-3 
per  cent,  of  an  ingot  weighing  150  grammes  (nearly  5  ounces) 
was  vaporised  in  Qh  minutes.^  The  gold  thus  volatilised  condenses 
either  as  deep  yellowish-green  spherules,  coated  often  with  a  purple 
glaze,  or  as  filaments,  or  occasionally  as  minute,  brilliant  yellow, 
cubical  crystals.      In  a  vacuum  gold  commences  to  volatilise  at  a 


°  Leibius,  Proc.  Roy.  Soc.  N.S.W.,  XVIII,  1884,  p.  .37. 

b  Min.  Sci.  Press,  Feb.  28,  1908,  p.  195. 

('  Zeit.  anorg.  Chem.,  XLVI,  1905,  p.  244. 

d  Moissan,  Compt.  Rend.  Acad.  Sci.,  Paris,  CXLI,  1905,  p.  977. 


Plate  I. 


#  ■  v 


<£*>. 


Alluvial  Cold, 

Otago,    New   Zealakd. 

(Nat.  size.) 


Vein  Gold, 

Sentaschli  River,  Orenburg,  Russia. 

(Photo.    Dr.    Hatch.     f  nat.  size.) 


Vein  Gold, 

antioquia,  (  lolombia. 

(British  .Museum.     Nat.  size.) 


( rOLD  Crystals 

with  Blistered  Faces,  California. 

(British  Museum.       Nat.  size.) 


CRYSTALLIZED    COLD. 


ELECTRUM.  23 

temperature  of  1,070°  C.,rt  and  boils  at  1,800°  C.h  Under  atmo- 
spheric pressure  the  boiling  point  of  gold  is  estimated  at  2,530°  C.c 
Gold  is  attacked  in  the  dry  way  by  fluorine  at  a  temperature 
of  300°  C,  and  by  chlorine  under  the  same  conditions  at  200°  C. 
In  the  former  case  the  fluoride  formed  is  decomposed  on  increase 
of  temperature.  Tellurium  vapour,  according  to  Margottet,  attacks 
gold,  yielding  a  crystalline  telluride.^  Neither  sulphur  nor  selenium 
are  known  to  combine  directly  with  gold  ;  and  few  acids  have  any 
effect  on  it.  Mitscherlich,6  as  far  back  as  1827,  reported  its 
solubility  in  selenic  acid.  Gold  is  attacked  by  iodic  acid  in  the 
presence  of  sulphuric  acid  and  by  hydriodic  acid  in  an  ethereal 
solution.  The  usual  solvent  used  in  the  arts  is,  of  course,  aqua 
regia  (nitro-hydrochloric  acid).  Gold  is  also  soluble  in  fuming 
hydrochloric  acid,  in  oxygenated  hydrochloric  acid,  in  permanganic 
acid,  &c.  The  last  and  other  solvents  well  known  in  the  laboratory, 
however,  appear  to  have  little  scope  for  action  in  nature  and  need 
not  be  discussed  in  this  place. 


NATIVE   ALLOYS   OF   GOLD. 

Elect  rum. — The  electrum  of  Pliny  (probably  named  on  account 
of  its  yellow  colour,  from  the  HXeKTpov,  or  amber,  of  Strabo)  was 
defined  as  a  natural  alloy  containing  one-fifth  of  silver.  The  term 
is  occasionally  used  by  modern  writers  to  cover  natural  gold-silver 
alloys,  but  has  not  met  with  general  acceptance,  its  place  being 
supplied  by  an  extension  of  the  term  "  gold."  Electrum  is  derived 
almost  entirely  from  the  Tertiary  andesitic  goldfields  of  North, 
South,  and  Central  America,  New  Zealand,  and  Hungary.  Its 
colour  varies,  with  the  percentage  of  silver  present,  from  yellowish 
white  to  pale  yellow  ;  its  specific  gravity  ranges  between  12-5  and 
15-5.  The  proportions  of  gold  and  silver  present  are  often  molec- 
ular, and  may  for  the  given  cases  indicate  definite  chemical 
compounds,  as  was  first  pointed  out  by  Boussingault./  It  is, 
however,  probable  that  in  the  majority  of  occurrences  electrum  is 
composed  of  an  exceedingly  intimate  mixture  (an  isomorphous  solid 
solution)  of  gold  and  silver. 

The  occurrence  of  electrum  or  low-grade  gold  in  the  veins 
of  the  younger  volcanic  deposits  alone  may  possibly  be  regarded 

"Schuller,  Zeit.  anorg.  Chem.,  XXXVII,  1903,  p.  69. 

6Krafft  and  Bergfeld,  Berichte  Chem.  Gesell.,  XXXVIII,  1905,  p.  254. 

c  Moissan,  loc.  cit.  sup. 

d  Margottet,  Ann.  de  l'Ecole  normale,  VIII,  1879,  p.  247. 

e  Ann.  Phys.  Chem.  Pogg.,  IX,  1827,  p.  623. 

/  Ann.  Chem.  Phys.,  XXXIV.  1827,  p.  408. 


24  NATIVE    ALLOYS    OF    GOLD. 

as  evidence  of  a  more  or  less  direct  magmatic  origin  for  the  electrum. 
Here  the  gold  is  still  associated  with  the  metallic  impurities  of  the 
solfataric  waters  in  which  it  has  made  its  ascent  towards  the  surface  ; 
the  alloy  has  not  yet  been  subjected  to  those  selective  agents  of 
solution  and  precipitation  that  have  had  abundant  opportunities 
in  time  and  space  to  refine  the  gold  of  the  older  vein  deposits.  Even 
if  the  gold  of  ancient  veins  does  not  represent  the  end-product  of 
processes  of  solution  and  precipitation  many  times  repeated,  at 
least  it  often,  as  in  the  Ordovician  rocks  of  Victoria,  denotes  a  long 
journey  in  space  through  fissures  of  rocks  capable  of  exercising  a 
selective  action  on  the  metals  of  passing  solutions. 

Maldonite. — Maldonite  or  bismuth-gold  is  a  well-defined 
compound  of  gold  and  bismuth.  It  was  discovered  and  described 
by  Uhlricha  from  the  quartz  of  the  Nuggetty  Reef,  Maldon,  Victoria. 
It  occurred,  when  originally  described,  only  as  minute  grains  and 
specks,  but  the  outcrop  and  upper  zones  of  the  Nuggetty  Reef 
contained  considerable  quantities  of  the  bismuth-gold,  or  "  black 
gold,"  as  it  was  termed  by  the  miners.  Its  mineralogical  characters 
are  :  hardness,  1-5  to  2-0  ;  malleable  ;  very  sectile  ;  very  bright 
metallic  lustre  and  pinkish  silver- white  colour  when  freshly  broken, 
but  tarnishing  gradually  on  exposure,  first  to  a  dull  copper  colour 
and  ultimately  to  black.  No  crystal  forms  have  been  observed. 
Heated  on  charcoal  before  the  blowpipe  it  readily  melts  in  the 
oxidising  flame  to  a  bead  of  gold,  yielding  the  usual  yellow  bismuth 
incrustation  on  the  charcoal.  The  following  analyses  have  been 
made  : — 


Au. 

Bi. 

Analyst. 

64  5 
6512 

35-5 
34-88 

Newbery. 
Mclvor.^ 

To  this  group  belongs  the  somewhat  doubtful  bismuthaurite  of 
Shepardc  from  Rutherford  County,  North  Carolina,  where  the 
mineral  occurred  in  small  malleable  palladium-like  grains.  Hardness, 
2  to  3;  and  specific  gravity,  12 -44  to  12-90.  It  has  generally  been 
considered  an  artificial  product,  and  is  not  mentioned  by  Genth  in  his 
catalogue  of  the  minerals  of  North  Carolina.^ 


a  Contrib.  Mineral.  Victoria,  Melbourne,  1870,  p.  4. 
/;  Mclvor,  Chem.  News,  LV,  1887,  p.  191. 
fAni.  Jour.  Sei.,  XXIV,  1857.  pp.  112,  281. 
^Bull.    No.  74.     U.S.  Geol.  Surv.,  1891. 


RHODITE.  25 

Nenadkevitch  "  reports  bismuth-gold  approaching  to  bismuth- 
aurite  from  the  telluric  and  bismuth  ores  of  Schil-Isset  in  the  Urals. 

Rhodite. — The  rhodium-gold  alloy  or  rhodite  of  Adam^  is  of 
doubtful  occurrence  in  nature.  It  has  been  described  only  by 
Del  Rio,  and  that  nearly  a  century  ago,c  from  material  afterwards 
said  to  have  come  from  the  placers  of  Mexico  and  Colombia.  It  was 
said  to  contain  34  to  43  per  cent,  of  rhodium,  and  to  have  a  specific 
gravity  of  15-5  to  16-8.  It  is  certainly  not  evident  from  Del 
Rio's  original  paper  (communicated  by  the  famous  traveller, 
Humboldt)  that  the  substance  examined  was  a  natural  alloy,  being, 
indeed,  designated  by  Del  Rio  simply  "  un  alliage  d'or.',rf  The 
material  was,  moreover,  obtained  at  the  Apartado  (mint)  of  Mexico, 
and  from  the  terms  of  Del  Rio's  description  it  would  appear  that 
the  alloy  described  had  been  obtained  after  melting.6 

Porpezite. — Palladium-gold  or  porpezite  was  named  in  error 
by  Frobel,./  after  the  supposed  name  (Porpez)  of  the  locality 
(Pompeo)  in  which  it  was  first  found. 0  Porpezite  of  a  dark  or 
bronze-like,  or  bright  copper-red  colour,  containing  5  to  10  per  cent, 
of  palladium,  together  with  a  little  silver,  is  found  in  the  Minas 
Geraes  province,  Brazil  (at  Jacutinga,  Condonga,  Sabara,  Gongo 
Socco,  &c).  Seamon^  found  in  porpezite  from  Taguaril,  Brazil, 
Au  91-06  and  Pd  8-21  per  cent.,  corresponding  therefore  to  the 
formula  Pd  Au0.  Its  specific  gravity  was  15"  73.  Palladium -gold 
has  also  been  reported  from  gold-washings  in  the  Caucasus,  near 
Batoum.' 

Ruer,J  however,  concludes  from  an  examination  of  the  freezing- 
point  curves  of  artificial  alloys  of  gold  and  palladium  that  these 
alloys  form  a  continuous  series  of  mixed  crystals,  and  that  there  is 
no  indication  of  chemical  combination.  The  fact  that  none  of  the 
three  elements,  copper,  silver,  and  gold,  enter  into  chemical  com- 
bination with  palladium  is  further  considered  by  Ruer  to  exemplify 
Taumann's  rule,*  according  to  which  either    all  or  none  of    the 


aMin.  Jour.,  Oct.  19,  1907. 

b  Tableau  Mineralogique,  1869,  p.  83 

c  Annales  de  Cliemie  et  de  Physique,  XXIX,  1825,  p.  137  ;     Ann.  des   Mines.  XII, 
1826,  p.  323. 

d  Ann.  de  Chem.  Phys.,  XXIX,  p.  138. 

e  I  can  find  no  authority  for  the  statement  (e.g.,  Cumenge    and  Robellaz,  "  L'Or 
dans  la  Nature,"  Paris,  1898,  p.  65)  that  the  material  examined  came  from  Colombia. 
/  Haidinger,  Handbuch  der  bestimmenden  mineralogie,  1845,  p.  558. 
9  Dana,  System  of  Mineralogy,  1892,  6th  Edition,  p.  15. 
^  Chem.  News,  XLVT,  1882,  p.  216. 
*Wilm,  Zeitsch.  anorg.  Chem.,  IV,  1893,  p.  300. 
ilb.  LI,  1006,  p.  391. 
k  Jour.  Chem.  Soc,  1906,  A.  II,  p.  346. 


26  NATIVE   ALLOYS    OF   GOLD. 

elements  of  a  natural  group  in  the  narrower  sense  enter  into  chemical 
combination  with  each  other. 

Amalgam. — Gold  amalgam  occurs  native.  It  contains  a  variable 
proportion  of  mercury,  and  is  apparently  of  indefinite  composition. 
Amalgam  with  57-4  per  cent,  mercury  is  reported  from  the  alluvial 
placers  of  Colombia."  Amalgam  from  Mariposa,  California,  yielded, 
on  analysis,  61  per  cent,  mercury,  and  had  a  specific  gravity  of 
15-47.^  In  placer  mines  that  have  long  been  worked  much  of  the 
amalgam  now  found  is  doubtless  of  secondary  origin,  due  to  the 
union  of  gold  with  quicksilver  lost  by  the  old  miners.  Native 
amalgam  is  found  in  the  gravels  of  the  Pek  river,  Servia,  where 
it  is  termed  "  zivak,"  and  in  Victoria,  in  the  quartz  of  the  German 
Reef,  Tarrangower.c  Artificial  crystals  of  gold-amalgam  show  faces 
of  the  octahedron,  cube,  rhombic  dodecahedron,  and  trapezohedron.^ 


"Schneider,  Jour,  prakt.  Che'm.,  XL1II,  1848,  p.  317. 

"  Sonnenschein,  Zeit.  deutsch.  geol.  Gesell.,  VI,  1854,  p.  243. 

f  Uhlricb,  Berg.  u.  Hiitt.  Zeit.,  XVIII,  1859,  p.  221. 


dld.,  Contrib.  Min.  Vict.  1866,  p.  82. 


27 


NATURAL  COMPOUNDS  OF  GOLD. 


Tellurides  of  Gold. — Of  the  numerous  salts  of  gold  only 
those  which  occur,  or  which  may  possibly  occur,  in  nature,  will  here 
be  considered.  Gold  is  an  element  forming  stable  compounds 
with  difficulty  even  in  the  laboratory  under  the  conditions  obtaining 
at  or  near  the  earth's  surface  ;  in  nature  its  stable  salts  are  restricted 
to  the  telluride  group,  if,  indeed,  even  these  be  definite  chemical 
compounds.  Members  of  this  group  were  first  described  from 
Zalathna,  Transylvania,  by  Klaproth,  in  1802.  They  form  notable 
additions  to  the  gold  content  of  the  veins  of  Nagyag  and  Offenbanya, 
in  Hungary,  where  they  have  been  mined  for  many  years.  Telluride- 
ores  of  gold  nevertheless  assumed  economic  importance  only  with 
the  discovery  of  the  rich  camps  of  Cripple  Creek,  in  Colorado, 
and  of  Kalgoorlie,  in  Western  Australia.  Prior  to  the  discovery 
of  the  Cripple  Creek  field  telluride-ores  had  been  known  in  Colorado 
since  1872,  and  had  been  worked,  with  indifferent  success,  in  Boulder 
County,  and  in  the  La  Plata  and  San  Juan  mountains.  Though 
their  presence  has  been  reported  during  the  past  10  years  from 
other  regions,  the  two  great  goldfields  above-mentioned  remain 
the  only  telluride  fields  of  economic  importance.  Gold-tellurides 
occur  at  Deutsch-Pilsen,  Bohemia  ;  Nagyag,  Offenbanya,  Za^thna, 
and  elsewhere  in  Hungary  ;  Mount  Morgan/'  and  Gympie,6  Queens- 
land ;  South  Lepanto,  Phillipine  Island  5  ;  Hauraki  Goldfields, 
New  Zealand/  where  it  has  been  determined  only  by  analysis  ; 
Rhodesia,  South  Africa,^  also  by  analysis  ;  Moss  Township,  Ontario 
(sylvanite)  ;  Dahlonega,  Georgia  ( sylvan ite)  ;  King's  Mount, 
North  Carolina  (nagyagite)  ;  Taku,  South  Yukon  (sylvanite)  ; 
Tonopah  and  Goldfield,  Nevada  ;  and  Shasta  and  Calaveras 
Counties,  California. 

It  is  characteristic  of  the  known  great  deposits  of  telluride-ores 
that  they  occupy  zones  or  belts  of  impregnation  or  fill  minute 
fissures,  and  are  not  associated  with  quartz  deposition  in  vein- 
fissures  or  with  silicification  of  the  country  adjacent  to  fissures. 
There  is,  nevertheless,  no  ground  for  a  consequent  assumption  of 
pneumatolytic  origin  for  telluride-ores  ;  they,  as  well  as  the  great 
majority  of  sulphide  ores  impregnating  country  or  filling  fissures, 

«Rickard,  T  A.,  Trans.  Amer.  Inst.  M.E.,  XXX,  1900,  p.  713. 
^  Dunstan,  Rec.  Geol.  Surv.  Queensland,  No.  2,  1904. 
c  Allen,  Trans.  Aust.  Inst.  M.E.,  VII,  1901,  p.  95  ;  Baker,  inlitt. 
^Mennell,  Proc.  Rhorl.  Sci.  Assn.,  1902. 


28  NATURAL  COMPOUNDS  OF  GOLD. 

may  best  be  considered  to  arise  from  deposition  from  heated  aqueous 
solutions.  In  this  connection,  however,  it  is  interesting  to  note 
that  Cossaa  determined  the  presence  of  tellurium  in  fumarolic 
concretions  from  the  crater  of  Vulcano  (Lipari),  and  succeeded  in 
separating  2 -J  grammes  of  pure  tellurium  from  three  kilograms 
of  the  concretionary  material.  The  concretions  contain  also  selen- 
sulphur,  arsenic  sulphide,  and  hieratite  (2  K  F.  SiF4),  together  with 
rarer  minerals,  the  whole  forming  a  most  suggestive  assemblage. 
Tellurides  of  gold  and  silver  when  brought  within  reach  of  surface 
oxidising  waters  are  readily  decomposed,  and  the  gold,  at  least, 
is  reduced  to  the  metallic  state,  in  which  condition  it  serves  as  a 
nucleus  for  the  precipitation  of  gold  from  wandering  solutions. 
As  Lenher  has  recently  shown,  reduction  is  also  effected  by  any 
of  the  natural  metallic  tellurides.  There  may  therefore,  in  the 
oxidised  zone  of  a  gold-telluride  vein,  be  found  both  a  dull  finely- 
divided  mossy  gold  ("  mustard  gold  ")  derived  directly  from  the 
decomposition  of  the  tellurides,  and  a  bright  lustrous  form  precipitated 
from  solutions.  It  is,  on  the  whole,  very  probable,  as  suggested  by 
Lenher b  from  his  failure  to  produce  definite  compounds  by 
synthetical  methods,  that  the  natural  tellurides  are  also  not  definite 
chemical  compounds,  but  are  rather  in  the  nature  of  alloys,  thus 
controverting  the  earlier  work  of  Brauner,c  who  had  asserted  that 
definite  crystalline  polytellurides  were  obtainable  in  the  laboratory.^ 

It  may  be  regarded  as  more  than  a  coincidence  that  the 
tellurides  of  gold  are  confined  to  regions  of  characteristic  andesitic 
facies,  or  to  the  Archaean  hornblendic  schists,  which  are,  as  will 
be  seen  later,  probably  to  be  considered  merely  as  metamorphosed 
prototypes  of  the  Tertiary  andesitic  complexes.  It  is  true  that 
through  the  auriferous  Archsean  schists  there  ramify  numerous 
diabasic  dykes  of  much  later  age,  but  it  will  be  shown  later  that  the 
work  of  these  dykes,  so  far  as  it  relates  to  auriferous  deposition, 
has  been  the  formation  of  quartz  lodes  with  free  gold.  The 
speculation  may  therefore  be  advanced  that  tellurides  of  gold  are 
directly  and  genetically  connected  with  magmas  of  intermediate 
composition. 

In  the  following  pages  the  various  naturally  occurring  tellurides 
are  described  with  some  detail. 

Calaverite. — Calaverite,  associated  with  petzite,  was  dis- 
covered by  Genthe  in  ore  from  the  Stanislaus  mine,  Calaveras  County, 

11  Atti.  del.  Accad.  Scienzc,  Torino,  XXXIII,  1897.  p.  450. 

b  Jour.  Am.  Chem.  Soc,  .XXIV,  1902,  pp.  358,  919. 

r  Jour.  Chem.  Soc,  LV,  1889,  p.  391. 

dSee  also  Margottet,  Ann.  de  1'Ecole  normale,  VIII.  1879,  p.  247. 

e  Am.  Jour.  Sci.,  XLV,  1868,  p.  314. 


CALAVERITE. 


29 


California.  It  is  found  in  considerable  quantity  at  Cripple  Creek, 
Colorado,  and  is  also  the  principal  gold-telluride  ore  of  the  famous 
Kalgoorlie  field  in  Western  Australia.  It  usually  occurs  massive, 
and  such  crystallized  specimens  as  have  been  found  have  been  too 
imperfect  to  admit  of  the  determination  of  the  crystallographic 
system.  Its  colour  is  pale  bronze-yellow  ;  when  scratched  it  gives 
a  yellowish-grey  streak.  Its  hardness  varies  from  2  to  3,  and  its 
specific  gravity  from  9  -311  to  9-377.  Unlike  sylvanite  and  krennerite 
it  has  no  perfect  cleavage,  and  breaks  with  an  uneven  fracture. 
Its  composition  is  best  represented  by  the  formula  Au  Te.,  (Au 
56-3,  Te  43-7)  to  which,  indeed,  its  analyses  show  it  to  be  fairly 
constant. 


Cripple  Creek 


99  99 

Kalgoorlie   . 


Te. 

Au. 

Ag. 

57-60 

39-17 

3-ai 

57-40 

40-83 

1-77 

57-30 

41-80 

0-90 

56-65 

41-76 

0-80 

59-69 

38-70 

1-66 

58-63 

37-54 

2-06 

60-30 

33-93 

4-82 

Insol.   0-33) 
Fe2O30-12/ 


Cu,  Fe,  S,  Pb,  Bi, 
Zn,  0-48 
Cu,  Fe,  Ni,  Se,  S, 
gangue,   1-81 
Cu,  Fe.  0-63      . 


Analyst. 

Hillebrand 

?  ? 

99 

Mingaye 
Rogers 

Kliiss 
Carnot 


Before  the  blowpipe  on  charcoal,  calaverite  fuses  with  a  bluish 
green  flame,  leaving  a  yellow  bead  of  gold.  Heated  in  the  closed 
tube,  it  gives  a  black  sublimate  of  metallic  tellurium,  and  a  less 
volatile  yellow  (hot)  or  white  (cold)  sublimate  of  tellurous  oxides. 
The  gold  beads  obtained  either  on  charcoal  or  in  the  closed  tube 
often  show  the  phenomenon  of  recalescence — a  sudden  secondary 
flashing  and  glowing  of  the  bead,  due  probably  to  the  presence 
of  a  small  quantity  of  tellurium.0 

Calaverite  has  been  recorded  from  the  Stanislaus  mine, 
Calaveras  County,  California,  associated  with  petzite  ;  from  the 
Red  Cloud,  Keystone,  and  other  mines,  Boulder  County,  Colorado, 
associated  also  with  petzite  ;  from  the  Cripple  Creek  district,  Teller 
County,  Colorado  ;  and  from  the  mines  of  Kalgoorlie,  Western 
Australia,  where  it  occurs  with  sylvanite,  krennerite,  and  petzite. 
It  is  said  to  occur  also  in  the  Southern  Lepanto  district,  Phillipine 
Islands. 

Sylvanite. — Telluride  of  gold  and  silver.  Type  formula  : 
(Au  Ag)  Te.,  ;    but  the   mineral   as   occurring  in    nature   appears 


"Spencer,  L.  J.,  Min.  Mag.,  XIII,  1903,  p.  270. 


30 


NATURAL  COMPOUNDS  OF  GOLD. 


to  have  a  fairly  constant  composition  that  may  be  represented  as 
Au  Ag  Te4.  Axes  ;  a  :  i  :  c  -.  =  1-63394  :  1  :  1-12653  ;  fi  =  89°  35' 
=  001  A  100.  System  of  crystallization  :  monoclinic.  The 
observed  forms  have  been  :  orthopinacoid  (100)  ;  clinopinacoid 
(010)  ;   basal  plane  (001)  ;    unit  prism  (110)  ;    orthodiagonal  prisms 


Figs.  49-57.     Sylvanite  (Graphic  Tellurium)  feom  Nagyag  and  Offenbanya  (Schrauj). 
a=(100),6=(010),c=(001),m=(110),/=(210),d=(001),ar=(012),M=(I01),N=(201),m=(101), 
»=(201),  Q=flll),  D=(221),  r=(lll),  <r=(121),  L=(522),  j,=(341),  «=(121),  y=(123),  »=(321), 
4=(323),  1=  (211),  oc=(414). 

(210),  (310),  (510)  ;  clinodiagonal  prism  (120)  ;  orthodomes  (101), 
(201),  (301),  (101),_(201),  _(301)  ;  _clinodomes  (001),  (012),  (021); 
hemi-octahedrons    (Til),    (112),    (223),    (221),    (111),    (112),   (221); 


SYLVANITE. 


31 


orthodiagonal  pyramids  (414),  (314),  (313),  (311),  (621),  (525), 
(723),  (521),  (213),  (212),  (211),  (421),  (323),  (321),  (542);  (721), 
(621),  (311),  (522),  (521),  (213),  (212),  (211),  (421),  (323),  (321), 
(542)  ;  clinodiagonal  pyramids  (341),  (343),  (231),  (121),  (122), 
(123),  (381),  (131),  (141),  (292),  (161);  (671),  (341),  (231),  (121), 
(122),  (123),  (381),  (131),  (141).  Twinning  plane:  the  orthodome 
(iOl).  Twinned  members  occur  as  contact  twins,  as  twinned 
lamellae,  and  as  penetration  twins,  giving  rise  to  branching 
arborescent  forms  crossing  at  angles  of  69°  44'  and  resembling 
written  characters  (whence  the  name  grajjhic  tellurium,  Ger.,  Schrift- 
tellur).  Skeletal  forms  common,  also  bladed,  and  imperfectly 
columnar  to  granular.  Cleavage  :  perfect,  parallel  to  the  clinopina- 
coid  (010).  Fracture  uneven.  Brittle.  Hardness,  1  •  5  to  2.  Specific 
gravity,  7-9  to  8-3.  Lustre  :  metallic,  brilliant.  Colour  and  streak 
pure  steel-grey  to  silver-white,  sometimes  nearly  brass-yellow. 
The  following  are  the  principal  analyses  available  : — 


Locality. 

Te. 

Au. 

Ag. 

S.G. 

Analyst. 

(Cu    0-76 

Offenbanya 

59-97 

26-97 

11-47 

Pb   0-25 
iSb    0-58 
|Pb  tr. 

8-28 

Petz 

Nagyag 

61-98 

26-08 

11-57 

Cu    0-09 

'Fe    0-40 

8-036 

Hanko 

Red  Cloud   ] 
Colorado       ) 

59-78 

26-36 

13-86 

/Cu  0-32 
)  Fe  0-16 
]  Ni  0-10 
lSe  0-20 

7-94 

Genth 

Kalgoorlie 

60-83 

28-55 

9-76 

Krusch 

Cripple  Creek . . 

60-82 

26-09 

12-49 

Fe  1.19,  Insol.  1-02 

8-161 

Palache 

In  the  open-tube  sylvanite  yields  a  white  sublimate  of  tellurium 
oxide,  which  near  the  assay  is  grey  ;  the  sublimate  when  treated  with 
the  blowpipe  flame  fuses  to  clear  transparent  beads.  When  heated 
before  the  blowpipe  on  charcoal,  sylvanite  fuses  to  a  dark-grey 
globule,  covering  the  coal  with  a  white  coating,  which,  treated 
with  the  reducing  flame,  disappears,  giving  a  bluish-green  colour 
to  the  flame  ;  after  Jong  blowring  a  yellow  malleable  metallic  globule 
of  gold  is  obtained.  Most  varieties  give  a  faint  coating  of  lead  oxide 
and  antimony  trioxide  on  charcoal." 

Sylvanite  derived  its  name  from  its  earliest  known  occurrence 
in  the  Transylvanian  mountains  (Franciscus  and  Barbara  mines, 
Offenbanya).      Elsewhere    in    the  Siebenburgischen  Erzgebirge    it 


°  Dana,  "  System  of  Mineralogy,"  6th  Ed.,  1892,  p.  104. 


32 


NATURAL  COMPOUNDS  OF  GOLD. 


occurs  at  Zalathna,  Nagyag,  and  Faczebaj.  An  occurrence  has 
been  noted  from  Deutsch-Pilsen,  Hungary.  In  the  United  States 
of  America  it  has  been  recorded  from  the  Stanislaus  and  Melones 
mines,  Calaveras  County,  California  ;  from  the  Red  Cloud,  Grand 
View,  and  Smuggler  mines,  Boulder  County,  Colorado  ;  from 
many  Cripple  Creek  mines  ;  and  from  Balmoral  and  Preston 
in  the  Black  Hills  of  South  Dakota,  where  gold-telluride  ores  occur 
in  a  dolomitic  limestone. a  In  Canada,  sylvanite  is  reported  from 
the  Huronian  mine  in  the  Thunder  Bay  district  of  Ontario.  Large 
quantities  have  also  been  found  at  Kalgoorlie,  Western  Australia. 

Mullerine. — Mullerine  is  a  brass-yellow  telluride  of  gold, 
silver,  antimony,  and  lead,  from  Nagyag,  Transylvania.  It  appears, 
however,  to  be  merely  a  variety  of  sylvanite  or  of  krennerite,  the 
presence  of  antimony  and  lead  being  due  to  impurities.  Like 
krennerite  it  decrepitates  under  the  blowpipe,  and  as,  according 
to  Krenner  and  Schrauf,  its  angles  are  identical  with  those  of 
krennerite,  it  should  perhaps  be  referred  to  that  species  rather 
than  to  sylvanite.  The  following  analyses  have  been  made  of  the 
mineral  and  have  served  as  the  foundation  on  which  the  species 
has  been  differentiated  : — 


Te. 

Sb. 

Au. 

Ag. 

Pb. 

S.G. 

Analyst. 

White  Crystals    .... 

55-39 

2-50 

24-89 

14-68 

2-54 

8-27 

Petz 

?  J                     5?                                  .... 

48-40 

8-42 

28-98 

10-69 

3-51 

7-99 

jj 

Yellow  Crystals  .... 

51-52 

5-75 

27-10 

7-47 

8-16 

8-33 

*  * 

Yellow,  Massive .... 

44-54 

8-54 

25-31 

10-40 

11-21 

?  * 

?»                               5  J                        .... 

-49-96 

3-82 

29-62 

2-78 

13-82 

9i 

?.                                   ,)                           .... 

44-75 

26-75 

8-50 

19-50 

Klaproth 

The  goldschmidtite  of  Hobbs^  has  proved  on  further  exami- 
nation of  the  type  crystals  and  of  fresh  material  to  be  referable 
to  sylvanite,  representing,  however,  a  peculiar  crystal  habit  of  that 
mineral.  The  original  material  on  which  the  term  goldschmidtite 
was  founded  came  from  the  Gold  Dollar  mine,  Cripple  Creek, 
Colorado.  The  differentiation  of  goldschmidtite  as  a  distinct 
mineral  species  has  therefore  been  abandoned  by  Hobbs.c 

Krennerite — Krennerite  was  first  described  by  Vom  Rath.rf 
It  differs  from  sylvanite  only  in  crystallization,  and  when  both  are 
massive  the  separation  into  species  is  impracticable.     It  crystallizes 


a  Smith,  F.  C,  Jour.  Pract.  Cliera.,  VI,  1898,  p.  67. 
b  Am.  Jour.  Sci.,  VII,  1899,  p.  357. 
c  Palache,  Am.  Jour.  Sci.,  X,  Ser.  4,  1900,  p.  426. 
d  Zeitsch.  Kryst,  I,  1877,  p.  614. 


KRENNERITE. 


33 


i 
c 


in  the  rhombic  system.  Axes,  a  :  b  :  c  :  —0-94071  :  1  :  0-50445. 
The  crystal  forms  observed  on  krennerite  have  been  :  n  Basal  plane 
(001)  ;  macropinacoid  (100)  ;  brachypinacoid  (010)  ;  unit  prism 
(110)  ;  macrodiagonal  prisms  (210),  (320)  ;  brachydiagonal  prisms 
(120),  (130)  ;  macrodomes  (102),  (101),  (201),  (301)  ;  brachydomes 
(011),    (021),    (031),    (041);     unit   pyramid    (111);     macrodiagonal 


ff^ 

^Az " * 

^ 

\ 

n  tti 

a  1 

m 

TL 

b 

C 

e 

j  | 

i 

fU/l 

T    h    T 

in. 

\_7 

^/ 

'  a 

Figs.  58  and  59.     Krennerite,  Nagyag  (Vom  Rath).        Fig.  60. — Krennerite  {Miers). 
a  =  (100), b=  (010), c=  (001) ,1  =  (320),  m  =  (110), n=  (120), h  =  (101), e=  (011), a  =  (021), 
q  =  (031),  a-  =  (041),  h  =  (110),  g  =  (102)..  Q  =  (201),  w  =  (124),  u  =  (122),  (  =  (121),  v  =  (362). 

pyramids    (211),    (322)  ;     brachydiagonal    pyramids    (122),     (124), 
(121),  (362). 

Crystals  of  krennerite  are  usually 
prismatic  and  vertically  striated.  Its 
cleavage  is  basal  and  perfect.  Fracture, 
sub-conchoidal     to     uneven.  Brittle. 

Hardness  ranges  from  2  to  3 ;  specific 
gravity:  8-3533.  Lustre  :  metallic, 
brilliant.  Colour  :  silver-white  to  brass- 
yellow.  Opaque.  Its  composition,  like 
that  of  sylvanite,  may  be  represented 
by  the  general  formula  (Au  Ag)  Te2, 
but  while  the  proportions  of  silver  and 
gold  in  sylvanite  are  fairly  constant, 
considerable  variation  has  been  observed 
in  krennerite,  as  is  shown  in  the  following  selected  analyses  : — 


r    m 


n 


m 


Fig.  61.     Krennerite,  Cripple 
Creek  (Penfield). 


Locality. 


Nagyag 


Cripple  Creek 
Kalgoorlie  . . . 


Te. 

Au. 

Ag. 

Sb. 

S.G. 

Analyst. 

39-14 

30-03 

16-69 

[9-75] 

S.  4-39 

5-598 

Scharizer 

45-59 

34-97 

19-44 

.   , 

.   . 

'5 

58-60 

34-77 

5-87 

0-65 

/Cu    0-34 
(Fe    0-59 

8-353 

Sipocz 

55-68 

43-86 

0-46 

.   . 

.   . 

Chester 

58-63 

36-60 

3-82 

.    . 

.  . 

Frenzel 

56-65 

41-76 

0-80 

Pittman 

a  Dana,  loc.  cit.,  p.  105  ;   Miers,  Min.  Mag.,  IX,  1890,  p.  184. 
C 


34 


NATURAL    COMPOUNDS    OF    GOLD. 


When  heated  before  the  blowpipe,  decrepitates  violently,  but 
is  otherwise  like  sylvanite  or  calaverite.  Occurs  at  Nagyag,  Tran- 
sylvania, in  the  Independence  mine  ;  Cripple  Creek,  Colorado,  and, 
somewhat  doubtfully,  at  Kalgoorlie."  In  Western  Australia  it  is 
also  reported  from  near  Lake  Lefroy  and  from  Broad  Arrow. 

Petzite. — Petzite  is  a  telluride  of  silver  and  gold.  It  has  not 
been  observed  in  crystal  form.  Fracture,  sub-conchoidal.  Slightly 
sectile  to  brittle.  Hardness,  2-5  to  3.  Specific  gravity,  8-7  to  9-02. 
Lustre,  metallic.  Colour,  steel  or  iron-grey  to  iron-black  ;  often 
tarnished.  Its  composition  is  represented  by  the  general  formula 
(Ag  Au)2  Te,  as  indicated  by  the  following  analyses  : — 


Nagyag    

Stanislaus  Mine,  ) 

California  ) 
Red  Cloud  Mine,  : 

Colorado  j 
Kalgoorlie 


Te. 


34-98 
32-23 

33-49 

32-60 
31-58 


Ag- 


46-76 
42-14 

40-73 

40-70 
43-31 


Au. 


18-26 
25-63 

24-60 


Bi,Pb,Zn,  Fe,Si0.2  =  2-12 
Cu,  Fe,  Ni,  Se,  S,  Si02  =2-08 


24-33 

23-58   Hg,  Cu,  Fe,  Sb,=  l-38 


Analyst. 


Petz 
Genth 


Wolbling 
Carnot 


The  actual  formula  may  therefore  be  written  3  Ag2  Te  Au2  Te, 
or  Ag3  Au  Te2. 

Before  the  blowpipe  petzite  is  much  more  refractory  than  the 
other  gold-silver  tellurides,  requiring  the  addition  of  sodium  car- 
bonate for  reduction  to  a  metallic  bead.  It  is  with  difficulty 
distinguishable  by  its  physical  characters  alone  from  coloradoite, 
the  mercury-telluride. 


---—.-j (-' 


Figs.  62  and  63.     Hessite  from  Botes,  Hungary  (Becke). 
h  =  (100),  d  =  (110),  e  =  (210),  o  =  (111),  i  =  (211),  p  =  (221). 

Hessite — Hessite  is  normally  a  silver-telluride,  but  since 
variable  portions  of  the  silver  are  occasionally  replaced  by  gold, 
some  mention  of  it  must  here  be  made.    It  crystallizes  in  the  cubic 


;  Spencer,  L.  J.,  Min.  Mag.,  XIII,  1902,  p.  262. 


PETZITE. 


35 


system  with  the  observed  forms  :  Cube  (100)  ;  octahedron  (111)  ; 
dodecahedron  (110)  ;  tetrahexahedron  (310),  (210)  ;  trigonal 
trisoctahedron  (221),  (331);  trapezohedron  (311),  (211),  (322). 
Cleavage,  indistinct.  Fracture,  even.  Somewhat  sectile.  Hardness, 
2-5  to  3.  Specific  gravity,  8-31  to  8-45;  another  determination 
is  8-89.  Lustre,  metallic.  Colour,  between  lead-grey  and  steel- 
grey.  Its  composition  is  ordinarily  represented  by  the  formula 
Ago  Te,  but  with  a  considerable  quantity  of  gold  present  it  approaches 
petzite.  The  following  are  analyses  showing  high  percentages 
of   gold  : — 


Locality. 


Nagyag 

Stanislaus  Mine,  ) 
California         ) 

Red  Cloud  Mine,\ 
Colorado  / 


Te. 


34-98 

44-45 

32-52 

37-17 

34-91 
32-97 


Ag. 


46-76 
46-34 

41-93 

59-75 

50-56 

40-80 


Au. 


18-26 
3-28 

25-55 

3-33 

1J-09 
24-69 


Pb  1-65,  Ni  -471 


Fe,  Cu,  SiO2=0-39 

Fe,  Cu,  Pb,  Zn,Si0o  =  l-45 
Fe,  Zn,  Si02=l-54 


Analyst. 


Petz 

Genth 


Before  the  blowpipe  hessite  behaves  like  petzite,  fusing  to  a 
black  globule,  and  requiring  the  addition  of  sodium  carbonate 
for  the  production  of  a  white  metallic  bead.  Auriferous  hessite 
is  known  from  Nagyag  and  Botes  in  Transylvania  ;  from  the 
Stanislaus  mine,  Calaveras  County,  and  the  Golden  Rule  mine, 
Tuolumne  County,  California  ;  from  the  Red  Cloud  mine,  Boul- 
der County,  Colorado  ;  from  the  Kearsage  mine,  Dry  Canon, 
Utah  ;    and  from  the  Kara-Issar  district  in  Asia  Minor. 

The  kalgoorlite  of  Pittmanra  and  the  coolgardite  of  Carnot& 
are  two  mineral  species  founded  on  material  obtained  from  Kalgoorlie 
in  Western  Australia.  To  the  former  the  formula  Hg  Au2  Ag6  Te6 
was  given,  and  to  the  latter  (Au  Ag  Hg  Cu  Fe  Sb)2  Te3,  or  more 
simply  (Au  Ag  Hg)2  Te3,  it  being  therefore  regarded  as  a  sesqui- 
telluride  of  gold.  As  was  first  pointed  out  by  Rickard,c  and  con- 
firmed by  Spencer,^  kalgoorlite  is  in  all  probability  a  mixture 
of  coloradoite  (Hg  Te)  and  petzite  (Ag3  Au  Te2),  while  the  cool- 
gardite of  Carnot  is  regarded  by  Spencer  as  a  complex  mixture  of 
coloradoite,  petzite,  calaverite,  and  sylvanite.  To  this  assumption 
considerable  weight  must  be  attached,  since  neither  Pittman  nor 


a  Rec.  Geol.  Surv.  New  South  Wales,  V,  1898,  p.  203. 
6  Comptes  Rendus,  Acad.  Sci.,  Paris,  CXXXII,  1901,  p.  1298. 
c  Rickard,  T.  A.,  Trans.  Am.  Inst.  M.E.,  XXX,  1901,  p.  715. 
d  Spencer,  L.  J.,  Min.  Mag.,  XIII,   1903,  p.  283. 


36 


NATURAL  COMPOUNDS  OF  GOLD. 


Carnot  have  recorded  the  presence  of  coloradoite  in  the  samples 
analysed  for  the  above  determinations,  although  the  mercury- 
telluride  occurs  in  some  abundance  at  Kalgoorlie. 

Nagyagitc. — Nagyagite  is  a  sulpho-telluride  of  lead  and  gold 
with  antimony.  Orthorhombic  ;  axes  a:b:c  =  0-28097:l  :0-27607. 
The  following  forms  have  been  observed:'1  Brachypinacoid  (010); 
unit  prism  (110)  ;  brachydiagonal  prisms  (120),  (130),  (160)  ;  macro- 
dome  (101)  ;  brachydomes  (011),  (031),  (051)  ;   unit  pyramid  (111)  ; 

brachydiagonal  pyramids  (343),    (121), 
(252),    (131),   (141). 

Crystals  of  nagyagite  are  tabular 
parallel  to  the  brachypinacoid.  Brachy- 
pinacoidal  faces  striated.  Generally 
foliated.  Cleavage,  perfect,  brachy- 
pinacoidal.  Thin  laminae  flexible. 
Hardness,  1  to  1-5.  Specific  gravity, 
6-85  to  7-2.  Lustre,  metallic,  splen- 
dent. Streak  and  colour,  blackish  lead- 
grey.  Opaque.  The  composition  is 
deduced  by  Sipocz  as  Au2  Pbu  Sb3  Te7 
S17  ;  by  Priwoznik  as  Pbti  Au  Te(1  S8, 
and  by  Schroeder  as  Pb10  Au2  Sb2  TeG  S15.  The  following  are  typical 
analyses  on  specimens  from  Nagyag  :  — 


Fig.  64.     Nagyagite  (Schrauf). 

b  =  (010),  e  =  (120),  o  =  (160), 
^=(011),  /=(031)  9=(051);<=(1U), 
>•=  (121). 


Te. 

s. 

Sb. 

Pb. 

Au. 

Ag. 

Cu. 

Author. 

(a) 

30-52 

8-07 

50-78 

9-11 

0-53 

0-99 

Schonlein 

(&) 

18-04 

9-68 

3-86 

60-27 

5-98 

.    . 

Se    Trace 

Folbert 

(c) 

17-72 

10-76 

7-39 

56-81 

7-51 

.  . 

.    . 

Fe    0-41 

Sipocz 

(d) 

17-87 

10-03 

6-99 

57-16 

7-41 

.  , 

.    . 

Fe-  0-32 

Hanko 

(e) 

29-38 

10-65 

50-32 

7-98 

Se  Trace 
SiO,  1-56 

Priwoznik 

(/) 

19-10 

12-24 

6-08 

53-84 

9-53 

— 

Schroeder 

Before  the  blowpipe  nagyagite  forms  on  charcoal  two  coatings  : 
one,  yellow  and  near  the  assay,  of  lead  oxide  ;  the  other, 
further  away,  white  and  volatile,  consisting  of  a  mixture  of 
antimoniate,  tellurate,  and  sulphate  of  lead.  In  the  closed  tube 
it  gives  separate  sublimates  of  antimoniate  and  tellurate  of  lead 
and  of  antimony  trioxide  and  tellurous  oxide.  Treated  for  some 
time  in  the  oxidising  flame  a  bead  of  metallic  gold  results.  Occurs 
at  Nagyag  and  Offenbanya,  Transylvania  ;  at  Deutsch-Pilsen, 
Hungary ;  in  Colorado  with  other  tellurides ;  at  the  King's  Mountain 


a  Schrauf,  Zeitsch.  fur  Kryst.,  II,  1878,  p.  239;   Fletcher,  Phil.  Mag.,  IX,    1880,. 
p.  188. 


NAGYAGITE.  37 

mine,  North  Carolina  ;  and  doubtfully,  at  Friedrichsburg  in 
Virginia. 

Closely  related  in  physical  and  chemical  characters  and  to  be 
grouped  with  nagyagite  is  the  nobilite  of  Adam.a  This  mineral  is 
the  silberphyllinglanz  of  Breithaupt.6  It  was  found  in  the  gneiss 
of  Deutsch-Pilsen,  Hungary. 

The  compounds  of  gold  hereafter  to  be  treated  are  well  known 
in  the  laboratory,  but  have  not  been  detected  or  isolated  in  nature. 

Sulphides  of  Gold. — The  sulphides  of  gold  are  prepared 
with  ease  by  passing  sulphuretted  hydrogen  through  a  solution 
of  auric  chloride,  either  aurous  or  auric  sulphide  or  variable  mixtures 
of  the  two  being  formed  according  to  the  temperature  of  the  solution. 

Aurous  sulphide  (Au.>  S)  in  the  form  of  powder  is  steel-grey 
when  wet,  and  black  when  dry.  At  a  temperature  of  240°  C.  it  is 
completely  decomposed  within  a  few  hours.  Sulphuric  and  hydro- 
chloric acids  have  no  effect  on  it,  but  it  is  soluble  in  the  ordinary 
gold  solvents,  and  particularly  in  alkaline  sulphides,  and  also, 
according  to  Rose,  in  alkalis.  The  formula  of  the  salts  resulting 
in  cases  of  solution  in  alkaline  sulphides  is  probably  of  the  general 
form,  Au2  S3,  3  M,  S.  When  freshly  prepared  it  is  soluble  in  pure 
water  to  the  extent  of  at  least  1  gramme  per  litre, c  furnishing  a 
brown  liquid.  Solutions  of  aurous  sulphide  resembling  colloidal 
solutions  are  readily  obtained,  but  these  are  not  truly  colloidal,  being 
formed  by  the  suspension  in  the  solution  of  exceedingly  finely  divided 
material,  a  fact  that  assumes  some  importance  when  considering 
the  subterranean  transport  of  gold. 

Auric  sulphide  (Au2  S3)  is  formed  by  the  action  of  sulphuretted 
hydrogen  on  cold  solutions  of  auric  chloride.  It  is  readily  soluble 
in  alkaline  sulphides  forming  alkaline  thio-aurates.  Pure  auric 
sulphide  is  isolated  as  black  scales  having  a  decidedly  graphitic 
appearance.  It  is  decomposed  at  a  temperature  of  200°  C.d  Double 
auric  and  argentic  sulphides  have  long  been,  known/'  The  artificial 
double  sulphide  of  gold  and  silver  (2  Au2  S3,  5  Ago  S)  is  crystallized, 
is  unalterable  at  ordinary  temperatures,  and  possesses  a  specific 
gravity  of  8-159. 

Of  considerable  academic  interest  also  are  the  complex  sulphides 
of  gold,  silver,  lead,  copper,  and  iron,  prepared  in  the  dry  way 
by  fusion  by  Maclaurin/  in  New  Zealand.    In  these  the  gold  sulphide 

n  Tableau  Mineralogique,  18C9,  p.  35. 

h  Jour,  fur  Chemie  und  Physik  (Schweigg.),  I,  1828,  p.  17S. 
c  Moissan,  "  Traite  de  Chimie  Minerale,"  V,  602,  Paris,  190G. 
d  Antony  and  Lucchesi,  Gazzet.  Chem.  Ital.,  XX,  1903,  p.  601. 
e  Muir,  Bericht.  Chem.  Gesell.,  V,  1872,  p.  537. 
/Trans.  Chem.  Soc,  LXIX,  1896,  p.   1269. 


38  COMPOUNDS    OF    GOLD. 

invariably  showed  the  formula  Au2S,  suggesting  an  -ous  combination 
of  the  gold,  in  similar  natural  auriferous  sulphides.  A  sulpho- 
telluride  of  gold  (Au.,  S3,  Te  So)  has  also  been  artificially  prepared. 
Native  gold  sulphide  has  from  time  to  time  been  reported, 
but  the  report,  as  that  from  Kalgoorlie,  has  always  been  based  on 
a  misconception,"  or  the  occurrence  is  merely  inferential.6  Gold 
sulphide,  as  a  mineral  species,  is,  therefore,  still  unknown,  and 
considering  its  susceptibility  to  the  influence  of  reducing  agents, 
its  existence  in  the  upper  zones  of  fissures  is  not  probable.  For 
the  same  reason  its  isolation,  should  it  indeed  exist  in  nature,  has 
not  yet  been  accomplished,  and  no  practical  method  has  yet  been 
devised  for  the  separation,  without  possible  reduction,  of  the  gold 
sulphide  from  the  base  metallic  sulphides  that  in  mining  furnish 
so  much  of  the  world's  gold.  Nevertheless,  it  is  highly  probable 
that  the  greater  part  of  the  gold  transported  in  the  deeper  zones 
of  circulation,  where  the  waters  are  normally  alkaline,  is  carried 
in  the  form  of  an  alkaline  auro-sulphide  (or  its  corresponding  ions). 
This  assumption  is  largely  relied  on  as  the  basis  of  a  working 
hypothesis  of  the  transference  of  gold  in  the  deeper  zones.  The 
question  will  again  be  referred  to  in  later  sections. 

Selenide  of  Gold. — The  formula  Alio  Se3  is  given  by  Ulsmann 
to  the  black  powder  obtained  by  passing  seleniuretted  hydrogen 
through  a  gold  chloride  solution.  The  presence  of  considerable 
quantities  of  selenium  in  the  crude  bullion  of  the  Waihi  mine 
in  New  Zealand  and  of  the  Radjang  Lebong  mine  in  Sumatra, 
and  at  Tonopah,  Nevada,  gives  ground  for  a  suggestion  that  the 
selenide  of  gold  may  be  a  natural  salt,  a  suspicion  strengthened 
by  the  natural  occurrence  of  presumably  analogous  tellurides  of  gold. 

Chloride  of  Gold. — The  readiness  with  which  the  chlorides 
of  gold  may  be  prepared  artificially  has  caused  many  to  assume 
that  it  is  in  this  form  that  gold  is  transported  in  nature.  While 
this  may  be,  and  probably  is  true  for  the  zone  of  surface-oxidising 
waters,  in  which  the  requisite  acid  waters,  oxides,  and  chlorides, 
may  readily  be  conceded  to  exist,  it  is  difficult  to  understand  how 
auriferous  chlorides  may  be  formed  in  the  deeper-seated  regions, 
and  still  more  so  to  see  how  they  can  escape  decomposition  imme- 
diately upon  formation  in  either  region.  The  case  for  the  existence 
of  chlorides  is  well  presented  by  Don,c  and  yet  his  own  experiments d 
go  to  show  that  whatever  the    form    in    which    gold    exists    in 

a  Hoover,   in  verb. 

h  Atherton,  Eng.  Min.  Jour.,  LII,  1891,  p.  698  ;    Williams,  ib.,  LIII,  1892,  p.  451. 

c  Trans.  Am.  Inst.  M.E.,  XXVII,  1897,  p.  599. 

dLoc.  cit.,  p.  604. 


CHLORIDE    OF    GOLD.  39 

the  deep-seated  region,  it  is  not  as  the  chloride.  Again, 
did  it  exist  in  sea-water  or  vadose  waters  as  a  definite  chemical 
compound,  it  should,  as  pointed  out  by  Lungwitz,a  remain  with 
the  mother  liquor  after  the  common  salt  had  crystallized  out. 
But  no  gold  has  been  reported  from  natural  deposits  from  the 
mother  liquor,  such  as  those  of  Stassfurt,  Lungwitz  himself  analysing 
50  pounds  of  carnallite  without  finding  a  trace  of  gold.  On  the 
other  hand,  Liversidge''  reports  gold  from  a  number  of  saline 
minerals,  as  sylvine,  kainite,  carnallite,  and  Chili  saltpetre.  The 
recent  researches  of  Lane,c  on  the  deep-seated  waters  contained 
within  rocks  obtained  at  great  depths  in  the  mines  of  Michigan, 
have  shown  that  concentrated  solutions  of  alkaline  chlorides  may 
exist  far  below  the  vadose  region.  In  view  of  this  determination  the 
assumption  of  the  general  restriction  of  the  possible  chloride  of  gold 
to  the  vadose  zone  must  be  held  to  be  subject  at  any  time  to  revision. 
Auric  chloride  (Au  Cl3)  when  prepared  in  the  laboratory  may  be 
either  hydrated  or  anhydrous.  The  latter  form  occurs  as  highly 
deliquescent,  deep  red  crystals,  crystallizing  in  the  triclinic  system 
and  melting  at  288°  C.  Its  density  is  4-3.  When  heated  it  decom- 
poses to  aurous  chloride  (Au  CI)  and  chlorine.  The  decomposition 
is  complete  in  three  years  at  a  temperature  of  100°  C,  and  under 
atmospheric  pressure  ;  at  a  temperature  of  200°  C.  only  36  hours 
are  required  to  effect  the  same  change.^  Solutions  of  gold  chloride 
are  readily  decomposed  by  exposure  to  heat  and  sunlight,  and  also 
by  carbonaceous  matter,  hydrogen  sulphide,  sulphurous  acid,  and 
other  natural  agents. 

Silicate  of  Gold. — A  possible  salt  of  gold,  to  which,  however, 
but  little  attention  has  been  paid,  is  the  silicate  of  gold.  The 
existence  of  this  salt  was  indicated  by  Bischoff,6  who  did  not 
fail  to  indicate  the  bearing  of  the  discovery  on  the  question  of  the 
origin  of  auriferous  veins.  Liversidge/  reported  that  gold  was 
dissolved  by  digestion  in  a  solution  of  potassium  or  sodium 
silicate  at  a  pressure  of  90  pounds  to  the  square  inch.  The  silicates 
were  further  investigated  by  Cumenge//  who  experimented  with 
an  alkaline  auro-silicate  obtained  by  adding  an  alkaline  aurate 
to  an  alkaline  solution  of  sodium  silicate  (water  glass).  While 
Cumenge's  experiments  have  been  repeated  and  confirmed  in  the 

a  Eng.  and  Min.  Jour.,  April  6,  1905. 

6  Jour.  Chem.  Soc,  LXXI,  1897,  p.  298. 

cAmer.  Geol.,  XXIV,  1904,  p.  302. 

d  Rose,  T.  K.,  "  Metallurgy  of  Gold."  London,  1902,  p.  24. 

e  Lehrb.  Chem.  Physik.  Geol.,  Ill,  1866,  pp.  843-6. 

•/"Proc.  Roy.  Soc.  N.S.W.,  XXVII,  1893,  p.  303. 

ffFremy,  Ency.  Chem.,  vol.  Ill,  L'Or,  p.  62. 


40  COLLOIDAL    GOLD. 

main  by  the  writer,  there  is,  nevertheless,  little  doubt  that  the 
red  and  blue  solutions  resulting  from  the  decomposition  of  the 
presumed  alkaline  auro-silicate  are  solutions  of  colloidal  gold 
and  not  of  gold  oxides,  as  suggested  by  Cumenge. 

Colloidal  Gold. — A  new  point  of  view  in  the  consideration 
of  the  transportation  and  deposition  of  gold  in  silicate  solutions 
is  furnished  by  the  researches  of  Schneider/'  Zsigmondi,^  and  others, 
on  colloidal  forms  of  gold.  Uncompleted  experiments  made  by  the 
writer  in  1901,  on  colloidal  gold  reduced  from  alkaline  auro-silicates 
by  addition  of  an  acid,  showed  that  the  colloidal  gold,  when  allowed 
to  stand,  exhibited  a  tendency  to  aggregate  round  indeterminate 
nuclei.  When  foreign  substances,  as  metallic  sulphides,  were  sus- 
pended in  the  jelly,  reaction  took  place  much  more  rapidly,  and  a 
clear  zone,  half  an  inch  wide,  of  gelatinous  silica  represented  the  dis- 
tance to  which  the  pyrites,  now  appreciably  gilded,  had  deprived  the 
jelly  of  its  gold.  Colloidal  gold,  like  all  other  colloids,  is,  however, 
so  readily  coagulated  by  electrolytes  (here  including  both  acids 
and  bases)  even  when  no  chemical  interaction  takes  place,  that 
its  existence  seems  to  be  compatible  only  with  the  presence  of 
pure  water,  a  condition  probably  rarely  existing  in  nature.  Both 
colloidal  gold  and  colloidal  silica,  moreover,  if  left  to  themselves, 
exhibit  the  phenomenon  of  "  chemical  after-effect,"  and  change 
spontaneously  to  less  soluble  forms — a  change  greatly  accelerated 
by  increase  of  temperature.0  On  the  whole,  therefore,  colloidal 
solutions  requiring  pure  water  and  low  temperatures  cannot  be 
supposed  to  play  a  prominent  part  in  auriferous  transportation. 

Ionised  Gold. — The  development  of  the  ionic  theory  of 
chemical  reaction  and  equilibrium  in  solutions  illuminates  also  the 
subject  under  present  discussion.  Since  the  free  energy  of  the 
complex  gold  ions  is  nearly  always  greater  than  that  of  the  elemen- 
tary aurion,  or,  in  other  words,  since  gold  has  a  greater  tendency 
to  exist  in  elemental  form  in  nature  than  as  a  compound,  it  seems 
reasonable  to  assume  that  the  gold  which  is  carried  from  place  to 
place  by  underground  waters  is  possibly  in  the  elemental  ionised 
form,  viz.,  aurion.  Ostwald,^  in  discussing  the  question  of  the  natural 
combination  of  acids  and  bases  in  natural  waters,  concludes  : 
'  The  final  answer  to  which  we  are  led  by  the  dissociation  theory, 
is  that  the  acids  and  bases  are  not  combined  at  all,  but  that  they — 
or  rather  the  ions  of  the  salts — lead  separate  existences,  to  which 

aZeit.  Anorg.  Chem.,  V,  1893,  p.  80. 

b  Liebig's  Annalen,  CCC,  1898,  pp.  29,  361. 

c  Zsigmondi,  "  Zur  Erkenntniss  der  Kolloide,"  Jena,  1905. 

d  "  Foundations  of  Analytical  Chemistry,"  Eng.  Ed.,  p.  213. 


GOLD    IN    SEA    WATER.  41 

the  only  limitation  is  the  law  that  the  sum  total  of  the  positive  ions 
must  be  equivalent  to  the  sum  total  of  the  negative." 

Next  to  the  elementary  aurion,  a  very  complex  ion  appears  to  be 
the  most  stable  of  the  gold  ions,  and  hence,  while  gold  is  probably 
generally  transported  as  aurion,  it  may  be  balanced  in  the  vadose 
regions  by  chloridion,  and  in  the  regions  of  deeper  underground 
circulation  by  sulphidion,  or  in  the  latter  regions  the  ion  may  be 
thio-auranion,  as  in  the  alkaline  thio-aurates  M2  Au  S2,  or 
auro-silicanion,  as  in  the  alkaline  auro-silicates  (M2  Au  Si  04), 
or  in  double  salts  corresponding  to  the  members  of  the  silicic  acid 
series. 

As  a  matter  of  fact,  the  only  natural  water  in  which  gold  has 
yet  definitely  been  determined  is  sea-water.  Its  existence  there 
was  foreshadowed  by  Forchammer,  and  confirmed  by  Sonstadt" 
in  1872.  Quantitative  experiments  conducted  by  Liversidge  on 
waters  from  the  coast  of  New  South  Wales  indicated  a  gold  content 
of  0-5  to  1-0  grain  of  gold  per  ton.&  Don's  careful  and  exhaustive 
experiments  (indeed  the  only  researches  yet  conducted  to  solve 
the  general  questions  of  auriferous  deposition)  gave,  however,  on 
waters  from  New  Zealand,  a  much  smaller  figure,  viz.,  -071  grain 
gold  per  ton. 

In  1892,  Munsterc  analysed  the  solid  contents  of  the  waters 
of  the  Kristiania  Fjord,  Norway,  finding  5  to  6  milligrams  gold, 
and  19  to  20  milligrams  silver  per  metric  ton.  Wagoner^  found  gold 
to  the  extent  of  11-1  milligrams,  and  silver  to  169-5  milligrams 
per  metric  ton  in  the  waters  of  the  Bay  of  San  Francisco.  Different 
methods  of  assay  have  been  used  by  different  chemists,  and  all  are 
not  of  the  same  degree  of  accuracy.  The  variation  shown  above, 
nevertheless,  probably  arises  from  the  great  distances  apart  at 
which  the  materials  for  analysis  were  collected.6  Liversidge  con- 
cluded from  his  researches  that  Muntz  metal  (a  copper-zinc  alloy 
used  for  sheathing  ships  and  pier  piles)  was  capable  of  removing  gold 
from  sea-water./ 


ftChem.  News,  XXV,  1872,  pp.  196,  231,  241. 

h  Trans.  Roy.  Soc.  N.S.W.,  XXIX,  1895,  p.  33."). 

c  Jour.  Soc.  Chem.  Ind.,  XI,  1892,  p.  351. 

d  Trans.  Am.  Inst.  M.E.,  XXXI,  1901,  p.  806. 

e  See  Weisler,   "  Ueber  den  Goldgehalt  des    Meer-wassers,"    Zeit.    angew.    Chem. 
1906,  p.   1795. 

/  Loc.  sit.  sup. 


42 


CLASSIFICATION    OF    AURIFEROUS    DEPOSITS. 

Auriferous  veins  or  deposits  may  be  of  any  form,  may  occur 
in  any  rock,  and  may  have  received  their  gold  from  various  sources. 
Particular  classifications  based  on  obviously  adventitious  characters, 
as  similarity  of  form  of  deposit,  or  identity  of  matrix  or  of  associated 
minerals,  can  therefore  serve  no  useful  purpose,  either  scientific 
or  economic.  Such  classifications  have  been  current  for  many  years. 
Some  have  certainly  been  suggestive,  but  the  majority  have  helped 
the  miner  and  prospector  not  a  whit,  and  have  proved  a  source 
of  confusion  and  embarrassment  to  the  student.  In  the  grouping 
of  the  world's  goldfields  adopted  in  this  treatise,  no  regard  whatever 
has  been  paid  to  the  lineal  forms  assumed  by  gold-quartz  or  other 
gold  ores.  The  shape  of  a  vein-deposit  or  of  an  ore-channel  is 
dependent  always  either  on  the  dynamic  conditions  prevailing 
antecedent  to  vein-filling,  or  on  characters  inherent  in  the  enclosing 
rock  or  rocks,  and  problems  affecting  this  question  belong  either 
to  the  mechanical  region  of  geo-dynamics  or  to  the  chemical  regions 
of  solution,  deposition,  and  metasomatism.  In  the  case  of  gold, 
metasomatic  criteria  are  few  and  of  little  value,  since  we  are  dealing 
with  an  element  easily  precipitated  in  metallic  form  and  yielding 
few  stable  compounds.  Nor  may  any  serious  consideration, 
from  a  classificatory  point  of  view,  be  given  to  the  problems  afforded 
by  the  minerals  generally  found  associated  with  gold  in  auriferous 
deposits,  for  those  that  may  reasonably  be  assumed  to  possess 
genetic  value  are  few  in  number  and  are  universally  associated. 
They  may  be  sharply  separated  into  two  great  divisions  :  (a)  The 
metallic  sulphide  group,  which  may  be  extended  to  include  the 
chemically  allied  metallic  tellurides ;  and  (6)  quartz.  The  members 
of  the  first  group  are  so  readily  interchangeable  that  no  subdivision 
is  possible,  and  their  connection  with  the  problems  of  auriferous 
deposition  must  be  regarded  always  from  the  group  point  of  view 
rather  than  from  the  standpoint  of  the  particular  mineral  {e.g.,  galena, 
pyrite,  stibnite,  &c).  The  gold  of  the  sulphide  group  is  nearly 
always  refractory,  and  as  already  seen,  is  possibly,  for  the  point 
is  not  capable  of  definite  proof,  in  a  state  of  combination  as  a 
sulphide.  The  visible  free  gold  often  found  associated  with  sulphides 
may  generally  be  considered  to  be  due  to  the  partial  decomposition 
of  the  sulphides,  or  to  the  reducing  effect  of  the  latter  on  wandering 
auriferous  solutions.  The  ores  of  the  auriferous  sulphide  group 
may  be  deposited  either  in  a  quartz  matrix  or  may  be  impregnated 
through  ore-channels  or  through  the  country  adjacent  to  fissures. 


AURIFEROUS   PROVINCES.  43 

The  quartz-gold  group  is  characterised  by  the  general  absence  of 
sulphides  of  obvious  relation  to  gold,  and  by  the  presence  of  free 
gold.  In  many  cases,  however,  the  broad  separation  of  gold-deposits 
indicated  above  can  not  be  held  to  be  valid,  for  the  free  gold  of  some 
gold-quartz  veins  is  certainly  derived  from  adjacent  sulphide-ores, 
and,  moreover,  solutions  in  the  same  vein  may  be  so  far  influenced 
by  the  country-walls  or  by  other  local  conditions  as  to  furnish  base 
sulphide  deposits  in  one  part  and  gold-quartz  in  another  part 
of  the  fissure.  This  feature  is  exemplified  both  on  a  small  and  on  a 
large  scale  in  the  goldfields  of  Eastern  Australia.  Veins  on  the 
Ravenswood  and  Etheridge  goldfields  in  Queensland  passing  from 
igneous  into  sedimentary  rocks,  show  a  marked  transition  from 
pure  sulphide  veins  in  the  former  to  gold-quartz  with  little  auriferous 
pyrite  in  the  latter.  On  the  larger  scale  it  may  be  noted  that  through- 
out the  Eastern  Australian  gold-belt,  from  Horn  Island  in  Torres 
Strait  to  Beaconsfield  in  Tasmania,  gold-quartz  veins  occur  in 
sedimentary  rocks,  and  auriferous  sulphide  veins  in  igneous  rocks. 
Exceptions  on  both  sides  do  occur,  but  the  exceptions  are  only 
apparent,  and  are  nearly  always  capable  of  a  local  explanation. 
Regarded  broadly,  there  is,  as  will  be  seen  later,  some  reason  for 
assuming  a  common  origin  for  the  gold  of  the  various  deposits  of 
this  belt,  and  the  indicated  difference  in  character  may  therefore  be 
assumed  to  be  due  to  the  diverse  geological  nature  of  the  respective 
country  rocks  in  which  the  deposits  occur. 

Auriferous  Provinces. — These  associations,  while  certainly 
indicative  of  the  conditions  under  which  gold  is  transported  and 
deposited,  help  us  little  in  the  search  for  the  original  host  of  the 
gold  of  the  earth's  surface.  The  most  natural  grouping  of  the 
world's  gold-deposits  appears  to  be  reached  by  a  combination  of 
geographical  and  geological  data,  resulting  in  the  establishment 
of  fairly  definite  auriferous  provinces,  well  separated  from  each 
other  either  in  time  or  in  space,  or  in  both.  The  individual  members 
of  each  group  possess  strong  affinities  that  can  hardly  be  coincidental. 
The  classification  here  adopted  is  to  be  regarded  as  merely  pre- 
liminary, for  it  must  certainly  be  modified  with  progress  in  the 
knowledge  of  ore-deposits.  Its  general  value  is  considered  to  lie 
largely  in  the  fact  that  the  differences  between  auriferous  provinces, 
no  less  than  their  resemblances,  are  emphasized.  Of  the  magmatic 
factors  that  have  governed  the  association  of  gold  with  igneous 
magmas  of  the  characters  indicated,  nothing  is  known,  nor  is 
anything  certain  with  regard  to  the  causes  of  extrusion  or  intrusion 
of  these  magmas  at  the  earth's  surface  ;  any  speculations  thereon 
must  be  of  the  vaguest.  The  writer  is  therefore  at  present  content 
to  submit  the  subjoined  as  the  most  natural  grouping  of  auriferous 


44 


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AURIFEROUS  PROVINCES.  45 

deposits,  and  offers  no  speculative  comment  on  the  internal  and 
external  relations  of  the  groups  indicated. 

Far  greater  regard  is  had  to  the  character  of  the  rock-magma 
with  which  the  gold  may  reasonably  be  supposed  to  have  had  a 
genetic  connection,  than  to  the  nature  of  the  rock  actually  enclosing 
the  deposit,  for  no  great  acquaintance  with  gold-deposits  is  necessary 
to  render  it  abundantly  apparent  that  gold  will  be  deposited  wherever 
physical  and  chemical  conditions  are  suitable,  irrespective  of  the 
nature  of  the  walls  of  the  fissure  or  cavity  through  which  the 
auriferous  solution  happens  at  the  time  to  be  passing.  A  wide 
interpretation  is  everywhere  given  in  this  treatise  to  geological 
phenomena.  For  example,  events  so  far  separated  in  time  as  the 
first  extrusion  of  an  igneous  magma  and  the  solfataric  action  that, 
in  the  same  region,  accompanies  the  quieter  or  the  final  stages  of 
volcanic  activity,  are,  in  the  absence  of  detailed  data,  regarded  as 
different  phases  of  the  same  phenomenon.  The  Tertiary  andesites 
of  Cripple  Creek,  Colorado,  and  the  geysers  of  the  Yellowstone 
Park — or,  to  take  another  case,  the  Upper  Eocene  andesites  of  the 
Hauraki  Peninsula,  New  Zealand,  and  the  hot  springs  of  the  central 
region  of  the  North  Island — have  each  a  common  origin,  and  are 
respectively  separated  only  in  time  and,  to  an  unimportant  degree,  in 
space.  Nor,  in  the  same  way,  is  much  regard  paid  to  "  lateral 
secretion"  or  "ascension"  hypotheses  of  origin  of  ores.  In  certain 
cases  in  igneous  rocks,  lateral  secretion,  even  in  its  older  and  more 
restricted  sense,  may  have  furnished  auriferous  vein-filling  ;  in 
others  in  the  same  region  the  gold  may  have  been  brought  from 
great  depths,  but  yet  has  been  derived  from  the  lower  portions  of 
the  same  magma  that  furnished  the  intrusions  or  extrusions  now 
at  the  surface.  Between  the  lateral  secretion  deposit  and  the 
ascension  deposit  thus  indicated,  no  logical  distinction  may  be  made. 
It  has  been  assumed  that  all  essential  operations  of  ore-deposition 
are  to  be  regarded  as  taking  place  in  the  outer  25  miles  of  the  earth's 
crust,  and  it  is  believed  that  lateral  secretion  may  operate  anywhere 
within  that  shell,  and  also  that  ore-bearing  waters  may  ascend  from 
that  and  from  lesser  depths. 

A  word  may  be  said  as  to  the  use  of  the  terms  primary  and 
secondary.  They  are,  in  an  investigation  of  this  nature,  purely 
relative.  The  primary  gold-deposits  are  those  of  which  we  know, 
for  the  gold,  no  prior  state  of  combination  and  no  former  locus 
in  space.  They  include  the  auriferous  sulphides  and  tellurides, 
and  many  free-gold  deposits.  They  may,  indeed,  have  undergone 
many  changes,  and  they  may  have,  in  a  former  geological  age, 
appeared  at  or  near  the  then  existing  surface,  for  sedimentary 
and  igneous  rocks  containing  gold-quartz  veins  and  deposits  may 
be  depressed  until  they  meet  with  a  liquid  or  potentially  liquid  magma 


46 


AECHJEAN    GROUP.  47 

eating  its  way  to  the  surface,  or  deeply-descending  waters  may 
carry  downward  gold  in  solution  ;  but  without  actual  evidence 
of  these  agents,  the  resultant  deposits  must  be  regarded  as  primary. 
Secondary  gold  deposits  are  those  obviously  or  presumably  derived 
from  sulphide  or  telluride  ores  or  from  gold-quartz  veins.  Examples 
of  this  form  are  found  in  the  "  sponge  "  and  "  mustard  "  gold  of 
Kalgoorlie,  and,  indeed,  in  the  greater  quantity  of  free  gold  within 
the  surface  oxidised  zones  of  veins.  Secondary  deposits  may  further 
be  either  of  chemical  origin,  as  the  foregoing,  or  of  mechanical  origin, 
as  the  placer-gold  of  gravels. 


PRIMARY     DEPOSITS. 


ARCH^AN    GROUP. 

The  primary  rocks  here  dealt  with  are,  next  to,  or  perhaps  with 
the  fundamental  gneisses,  the  oldest  rocks  that  are  available  for 
examination.  Partly  owing  to  the  conditions  prevailing  at  the  time 
of  their  deposition,  and  partly  owing  to  their  long  subjection  to 
metamorphic  agencies  that  have  tended  to  reduce  originally 
physically  and  chemically  differing  rocks  to  a  common  facies,  they 
show  a  remarkable  petrological  similarity  wherever  they  have 
been  examined,  whether  in  north-west  Scotland,  North  America, 
India,  Australia,  or  South  Africa.  All  the  members  have  been 
schisted,  many  indeed,  to  such  an  extent  as  to  render  it  now  difficult 
to  say  whether  they  were  originally  igneous  or  sedimentary.  Some 
schists,  however,  are  clearly  of  igneous  origin,  and  it  is  in  the 
amphibolitic  varieties  of  these  schists  that  the  oldest  known 
auriferous  deposits  occur.  The  Archaean  schists  are  of  course 
unfossiliferous,  and  their  correlation  in  widely  separated  areas 
can  be  performed  only  by  means  of  petrological  characters.  Never- 
theless, these  are  often  sufficiently  akin  to  warrant  a  general  grouping. 
The  best  defined  group  is  probably  that  found  bordering  the  Indian 
Ocean,  furnishing  the  rich  goldfields  of  Western  Australia,  India, 
and  south-eastern  Africa.  These,  though  geographically  widely 
separated,  present  so  many  points  of  similarity  that  a  geological 
description  of  the  various  Archaean  members  and  of  their  internal 
relations  in  any  given  region,  would  serve,  with  the  mere  change 
of  place-names,  for  any  other  region  of  the  group.  The  members 
are  consequently  believed  to  form  a  single  petrological  and  metal- 
logenetic  province.  For  this  province  the  appellation  Erythraean 
has  been  suggested. a 

a  Maclaren,  Trans.  Inst.  Min.  Met.,  XVI,  1907,  p.  15. 


48  AURIFEROUS  PROVINCES. 

In  America  a  similar  province  is  well  defined  in  the  Lake 
Superior  region.  There,  however,  its  auriferous  content  is  insig- 
nificant, and  the  province  is  characterised  by  its  copper  deposits 
rather  than  by  its  gold.  Its  southern  prolongation  is,  however, 
marked  by  the  long  chain  of  goldfields  that  extends  down  the 
eastern  slopes  of  the  Appalachians,  across  the  West  Indies,  and 
by  way  of  the  Guianas  and  Brazil  to  Tierra  del  Fuego.  The  possibly 
auriferous  character  of  these  Archaean  schists  is  masked  by  a  well- 
marked  auriferous  activity  due  to  the  intrusion  of  diabasic  and 
dioritic  dykes — an  activity  which  will  be  seen  to  be  world- wide  and 
will  be  described  as  such  in  later  pages.  These  two  great  provinces, 
the  Erythraean  and  the  Appalachian,  may  be  said  to  include  all 
the  Archaean  schist  goldfields  of  the  world,  though  it  may  be 
necessary  with  increase  of  knowledge  to  widen  the  group  to  include 
the  auriferous  schists  of  south-eastern  Siberia ;  the  sporadic 
Archaean  occurrences  of  South  Dakota,  Arizona,  &c,  are  to  be 
regarded  merely  as  outliers  of  the  longitudinal  chain  of  the  Eastern 
Americas. 

India. — Dealing  more  in  detail  with  the  various  members  of 
the  Archaean  group,  those  of  India,  where  the  relations  are  especially 
well  marked,  may  first  be  considered.  The  Dharwars  or  Archaean 
schists  of  India  are  typically  developed  in  Southern  India,  where 
they  extend  as  long  narrow  bands,  with  small  outliers,  from  the 
Bombay  Presidency  and  the  Nizam's  Dominions  southward  through 
the  Mysore  State. 

The  series  is  a  complex  aggregate  of  highly  metamorphosed 
rocks."  Among  the  more  easily  recognisable  sedimentary  rocks 
are  boulder-beds  or  conglomerates,  pebbly  grits,  quartzites,  lime- 
stones, argillites,  and  chloritic  schists.  The  boulders  of  the  boulder- 
beds  are  embedded  in  a  chloritic  schist  matrix,  and  are  rarely 
sufficiently  closely  aggregated  to  deserve  the  term  conglomerate. 
This  state  of  aggregation  is  highly  characteristic  of  the  coarser 
Archaean  sedimentaries,  and  has  been  assumed  by  some  geologists 
to  denote  glacial  origin.  The  feature  is,  however,  paralleled  in  the 
great  fan-like  deposits  of  many  existing  tropical  rivers  (e.g., 
the  Brahmaputra)  at  their  debouchure  from  the  mountains 
on  the  plains,  and  running  water  is  therefore  considered  to 
have  been  quite  competent  to  form  these  ancient  boulder- 
beds.  The  quartzites  are  in  places  metamorphosed  into  quartz- 
schists.  With  them  are  occasionally  associated  limestones,  but 
these  are  not  abundant.  By  far  the  most  characteristic  rock  of 
the  Archaean  group,  and  one  always  associated  with  the  sedimentary 
members  of  the  series,  is  a  well-banded,  generally  much  contorted, 

aMaclaren,  Rec.  Geol.  Surv.  India,  XXXIV,  1906,  p.  96. 


INDIA.  49 

hsematite-magnetite-quartz  rock  of  obscure  origin.  It  has  been 
thought  to  arise  from  silicification  along  shearing  planes,  but  it  may 
most  reasonably  be  regarded  as  due  to  the  metamorphism  of  ferru- 
ginous silicate  and  carbonate  bands  in  depth,  with  resultant  con- 
version into  ferric  oxides  and  silica.  Depression  of  banded  ferru- 
ginous clays  and  sands  should  eventually  yield  under  the  given 
conditions  a  rock  of  this  nature. 

The  members  of  the  Dharwars  derived  from  igneous  rocks  are 
mica-schists,  hornblende-schists,  certain  chloritic  schists,  amphi- 
bolites,  felsites,  and  quartz-porphyries,  representing  probably  a 
succession  of  fairly  basic  to  acid  rocks  such  as  may  be  met  with  in 
many  a  younger  volcanic  region.  Some  of  the  hornblendic  schists 
retain  sufficient  of  the  primary  structure  to  indicate  their  original 
diabasic  nature,  while  in  certain  light-coloured  varieties  the  ophitic 
structure  is  so  clear  that  the  rocks  may  fairly  be  termed  diabase- 
schists.  Where  the  hornblende-schists  have  been  influenced  by 
the  intrusion  of  younger  granites,  they  locally  lose  their  schistose 
structure,  and  by  reconstitution  of  their  fragmentary  felspars  and 
hornblendes,  assume  an  apparently  normal  dioritic  habit.  This 
change,  to  which  reference  will  again  be  made,  has  an  important 
bearing  upon  the  occurrence  of  metallic  gold  in  seemingly  unmeta- 
morphosed  igneous  rocks. 

Two  periods  of  vein  formation  and  auriferous  deposition  are 
observable  in  the  Dharwar  rocks.  The  older,  with  which  we  are 
presently  concerned,  is  to  be  associated  with  the  period  of  the 
general  dynamic  metamorphism  of  the  Dharwars,  and  finds  ex- 
pression in  the  veins  of  bluish  grey  and  bluish  black  quartz  that 
furnish  the  gold  of  the  Kolar  field  in  Mysore,  and  of  the  Hutti  field 
in  the  Nizam's  Dominions.  Microscopic  sections  of  this  quartz, 
especially  from  the  Hutti  mine,  show  that  it  has  been  subjected 
to  much  of  the  djTiamic  stress  that  has  affected  the  enclosing  rock. 
Its  structure  is  decidedly  schistose,  and  its  dark  colour  is  often  due, 
not  to  impurities,  but  to  total  internal  reflection  from  strain  surfaces. 
Its  gold  is  nearly  always  internal — certain  evidence  of  contem- 
poraneous deposition  of  gold  and  of  silica.  The  gold-quartz 
occurs  in  ;'  shoots,"  those  of  the  Kolar  vein  furnishing  probably 
the  best  examples  known  of  this  form  of  auriferous  disposition. 

Western  Australia. — To  the  Archaean  rocks  must  be  rele- 
gated the  ;c  Auriferous  Series ':  of  Western  Australia.  As  in 
Southern  India,  gneissoid  granites  are  believed  to  represent  the 
fundamental  rocks  of  the  country.  On  this  floor  has  been  laid 
the  great  series  of  rocks  to  which  the  general  field  term  "  greenstone 
schists  "  has  fitly  been  applied.  So  far  as  the  schists  have  been 
examined,  they  have  been  found  to  consist  in  the  main  of  amphi- 

D 


50  AURIFEROUS   PROVINCES. 

bolitic  and  hornblendic  members,  certainly  derivative  from  igneous 
rocks.  Near  the  younger  granitic  rocks,  the  hornblende-schists 
are  occasionally  so  far  reconstituted  as  to  form  diorites.  Mica- 
schists,  talc-schists,  chlorite-schists,  and  siderite-schists  also  occur, 
but  the  most  striking  rock  here,  as  in  India,  is  the  banded  haematite- 
magnetite-quartz  rock  which  runs  for  great  distances  parallel 
with  the  foliation  and  direction  of  the  main  schistose  belts, 
and  furnishes  the  saw-toothed  and  serrated  ridges  that  occupy 
such  a  prominent  position  in  a  greenstone-schist  area.  On  the 
Kalgoorlie  goldfield,  where  the  rocks  have  been  most  closely 
examined,  in  addition  to  the  prevailing  amphibolites  and  horn- 
blende-schists that  carry  the  auriferous  lodes,  there  also  occurs  a 
series  of  sedimentary  rocks  ranging  from  soft  shales  and  sandstones 
to  slates  and  quartzites.  The  first  are  often  highly  graphitic,  and 
then  contain,  as  might  be  expected,  numerous  nodules  and  crystals 
of  iron  pyrites.  Two  distinct  forms  of  auriferous  deposit  in  these 
rocks  may  be  referred  to  the  Archaean  period  :  (a)  "  lode  forma- 
tions," and  (b)  quartz  veins.  The  former  are  the  most  important 
loci  of  gold  in  the  State,  and  are  especially  well  developed 
at  Kalgoorlie,  Kanowna,  and  Peak  Hill.  ;'  Lode  formations  ':  are 
merely  zones  of  rock  impregnated  with  fine  gold  and  with  tellurides 
of  gold.  They  merge  insensibly  into  barren  solid  rock  on  either 
side,  and  are  probably  belts  of  sheared  and  fissured  rocks,  through 
which  mineral  solutions,  liquid  or  gaseous,  or  both,  have  had  free 
passage.  They  have  naturally  no  well-defined  walls,  and  their 
limits  are  determined  solely  by  their  assay  values. 

Quartz  veins  are  responsible  for  the  gold  on  the  majority  of 
Western  Australian  goldfields,  and  may  reasonably  be  divided 
into  two  classes — blue  and  white.  No  clear  distinction  as  to  their 
age  has  yet  been  made,  but  the  white  veins  appear  to  be  the  younger, 
since  they  cut  through  and  mineralize  many  of  the  banded 
haematitic  quartzites. a  The  white  veins  will  again  be  referred  to 
when  dealing  with  the  later  (Pre-Cambrian)  period  of  auriferous 
deposition  in  Western  Australia.  The  majority  of  the  older  quartz 
veins  occupy  shearing  planes  parallel  with  the  plane  of  foliation, 
and  within  a  given  zone  the  country  may  be  so  thoroughly  traversed 
by  them  as  to  form,  with  connecting  leaders,  a  stockwork.  The 
more  massive  veins  are  characterised  by  the  assumption  of  a  lenti- 
cular habit.  The  characteristic  minerals  of  the  chief  Western 
Australian  goldfield  are  the  tellurides  of  gold. 

South  Africa. — The  Archaean  rocks  of  South  Africa  show 
many  features  in  common  with  the  Dharwars  of  India,  and  with  the 
Auriferous    Series   of    Western   Australia.     The    Barberton   Series, 

a  Maitland,  Ann.  Rep.  West  Aust.  Geol.  Surv.,  1902,  p.  16. 


SOUTH    AFRICA.  51 

perhaps  best  developed  in  Swaziland,  resembles  very  strongly  the 
sedimentary  members  of  the  Dharwars.  Like  them,  the  charac- 
teristic rocks  are  chloritic  schists,  talc-schists,  argillites,  and  the 
ever-present  banded  haematite-quartz  rock,  which  here  as  elsewhere 
stands  out  in  bold  relief,  forming  the  mountain  ridges.  To  be 
correlated  with  these  ancient  rocks  are  the  series  of  schists  described 
by  Drs.  Hatch  and  Corstorphine  as  underlying  the  Witwatersrand 
Series  in  the  Bezuidenhout  Valley. a  The  Barberton  Series  of 
Swaziland  is  carried  northwards  to  the  Murchison  Range,  where 
the  schists  are  chloritic,  talcose,  amphibolitic,  and  quartzitic.  The 
auriferous  reefs  are  there  associated  with  the  hornblendic  schists. h 
Still  further  north,  in  Rhodesia,  and  obviously  connected  with  the 
Swaziland  schists,  are  the  Buluwayo  schists  of  Mennell,  which  in 
the  main  probably  represent  basic  igneous  intrusions.  Here  also, 
the  banded  hsematite-quartz  rock  is  a  dominant  feature  in  the 
physiography  of  the  region.  The  ancient  metamorphic  schists  of 
Zululand  and  Natal  are  grouped  by  Anderson0  with  the  Barberton 
Series  of  Swaziland,  as,  indeed,  may  also  be  the  highly  metalliferous 
schists  of  Namaqualand,  which  have  very  characteristic  diabasic 
and  amphibolitic  members.  These  rocks  have  for  German  South 
West  Africa  been  relegated  by  Voit  to  the  Archaean.'* 

Except  in  Rhodesia,  the  Archaean  schists  of  South  Africa  are 
not  in  themselves  of  economic  importance.  The  rich  gold-veins 
and  deposits  they  contain  are  generally  to  be  referred  to  a  later 
(Pre-Cambrian)  period  than  that  of  their  general  metamorphism, 
and  will  hence  be  dealt  with  under  their  proper  head. 

Appalachian  Fields. — These  He  along  the  outcrop  of  the 
Archaean  schists  of  Alabama,  Georgia,  South  Carolina,  and  North 
Carolina.  The  Archaean  series  contain  both  sedimentary  and 
igneous  members.  Representative  of  the  former  is  the  Talladega 
(Algonkian)  Series  of  Alabama,  consisting  of  slates,  quartzites, 
conglomerates,  and  dolomites.  The  igneous  series  is  a  complex  of 
green  schists,  basic  schists,  diorites,  and  gneisses.  The  "green 
schists  "  are  composed  in  the  main  of  actinolite,  epidote,  and  chlo- 
rite, together  with  some  quartz  ;  they  have  been  grouped  as 
chlorite-epidote  schists,  actinolite-epidote  schists,  and  chlorite 
schists.  It  is  difficult  to  determine  exactly  the  nature  of  the  original 
rock,  but  it  was  certainly  a  basic  eruptive. e  The  semi-crystalline 
slates  of  the  Goldville  region  contain  great  quantities  of  limonite 

a  Trans.  Geol.  Soc.  S.  Africa,  VII,  p.  98. 

&Merensky,   Min.   Jour.,   1905,  p.   629. 

c2nd  Rep.  Geol.  Surv.,  Natal,  1901,  p.  11. 

d  Trans.  Geol.  Soc.  S.A.,  VII,  p.   77. 

e  Clement  and  Brooks,  Bull.  5,  Alabama  Geol.  Surv.,  1896. 


52  AURIFEROUS   PROVINCES. 

pseudomorphous  after  pyrite.  Tetradymite  accompanies  the  gold  at 
King's  Mountain,  North  Carolina,  while  the  deposits  near  Dahlonega, 
Georgia,  contain  tellurides  of  gold.  Eckel's  examination  of  the  gold 
mines  of  the  latter  region  showed  that  the  veins  all  occurred  at 
contacts  between  the  soft  mica-schists  and  igneous  rocks,  either 
altered  schistose  diorite  (amphibolite)  or  massive  granite. a 

The  schists  of  the  Appalachian  goldfields  stretch  away  to  the 
north,  and  appear  to  be  associated  with  the  classic  greenstone- 
schists  of  the  Lake  Superior  region.  These  are  again  auriferous  in 
the  Rainy  Lake  region,  where  veins  occur  in  the  Coutchiching 
and  Keewatin  schists  and  run  parallel  with  the  schistosity.& 
In  the  Lake  of  the  Woods  region,  the  veins  are  mainly  in  the  Kee- 
watin schists,  though  gold-quartz  also  occurs  in  the  adjacent 
granites.  The  auriferous  deposition  here,  however,  appears  to  be 
associated  with  intruded  diabasic  dykes, c  and  must  therefore  be 
referred  to  the  second  or  Pre-Cambrian  period  of  auriferous 
deposition. 

South  Dakota. — In  the  Black  Hills,  South  Dakota,  there  lies 
a  belt  of  highly-metamorphosed  Archaean  schists  impregnated 
with  auriferous  pyrites  and  containing  numerous  lenticular  masses 
of  gold-bearing  quartz.  The  best-known  example  of  lodes  in  these 
rocks  is  the  Homestake,  where  a  portion  of  the  gold  is  obtained 
from  a  deposit  formed  along  a  schistose  zone  by  an  aggregation  of 
veinlets  containing  free  gold  and  low-grade  pyrite.  The  total  gold 
yield  for  the  nineteenth  century  of  these  American  Archaean  rocks, 
and  of  their  Pre-Cambrian  enrichments  yet  to  be  described,  was 
about  £28,000,000  sterling.** 

Brazil. — The  rocks  of  all  the  foregoing  Archaean  areas  are  so 
similar  that,  did  they  lie  in  comparative  proximity,  they  would  un- 
hesitatingly be  grouped  together  as  a  single  formation.  There  are 
other  ancient  schistose  rocks,  as  the  auriferous  schists  of  the  Minas 
Geraes  province,  Brazil,  that  are  doubtfully  to  be  grouped  under  this 
head.  The  age  of  the  Brazilian  rocks  is  uncertain,  and  they  have  been 
variously  referred  to  the  Archaean  and  to  the  Cambrian.  The 
fundamental  rocks  are  granite  and  gneiss,  and  these  are  overlain 
by  a  series  of  schistose  rocks.  The  series  in  ascending  order  is 
micaceous  and  talcose  schist,  quartzite,  argillaceous  schist,  itabirite 
with  jacutinga  (sandy  micaceous  iron  ore),  limestone,  and  the 
upper  micaceous  schist.6     All,  with  the  exception  of  the  limestone, 

a  Bull.  U.S.  Geol.  Surv.,  No.  213,  1903,  p.  57. 
6Geol.   Surv.   Minnesota,     XXIII,   1895,  pp.   35,   105. 
c  Trans.  Amer.  Inst.  M.E.,  XXVI,  1896,  p.  856. 
^Lindgren,  Trans.  Amer.  Inst.  M.E.,  XXXIII,  1903,  p.  801. 
e  Scott,  Trans.  Amer.  Inst.  M.E.,  XXXIII,  1903,  p.  409. 


BRAZIL.  53 

are  more  or  less  auriferous.  The  chief  forms  of  deposit  are  (a) 
lodes  in  the  schist,  (6)  contact  lodes,  and  (c)  auriferous  lines  of- 
jacutinga  in  the  itabirite.  The  lodes  in  schist  are  the  most  numerous. 
They  are  characteristically  lenticular,  and  dip  and  strike  with  the 
foliation.  The  gold  is  generally  associated  with  mispickel  and 
pyrrhotite.  The  contact  lodes  are  also  lenticular  masses  of  quartz 
intercalated  between  the  itabirites  and  the  underlying  quartzites 
or  argillaceous  schists.  To  this  class  belong  the  Passagem  and 
the  Morro  Santa  Anna  lodes.  The  Passagem  lode  contains  a  con- 
siderable amount  of  kaolinized  felspar,  and  has  hence  been  con- 
sidered by  Hussaka  and  Derby b  as  a  pegmatite  apophysis  rather 
than  as  a  true  quartz  vein.  The  rapidly  increasing  number  of 
occurrences c  reported  of  both  orthoclase  and  albite  as  vein-filling 
from  undoubted  aqueous  solutions  advise  considerable  caution  in 
the  complete  acceptance  of  this  determination.  The  jacutinga 
auriferous  deposits  are  now  of  but  little  importance.  The  celebrated 
Morro  Velho  mine  lies  in  a  zone  of  highly-sheared  calc-schist.^ 
The  auriferous  sulphides  are  arsenopyrite,  pyrrhotite,  chalcopyrite, 
and  pyrite,  with  a  gangue  of  siderite,  dolomite,  and  calcite,  with 
very  subordinate  quartz  and  albite  felspar.  The  last  also  occurs 
as  crystals  in  the  vughs. 

The  outstanding  feature  in  the  descriptions  of  the  Brazilian 
occurrences  is  the  absence,  with  one  exception,  of  all  mention  in 
the  literature  accessible  to  the  writer,  of  igneous  intrusions,  and 
these,  indeed,  appear  to  be  generally  absent  from  the  district.e 
The  exception  is  found  in  a  description  of  the  auriferous  occurrences 
of  Rapasos,/  in  which  it  is  stated  that  the  schistose  rocks  are 
traversed  by  two  diabase  dykes  and  that  the  ore-bearing  solutions 
are  to  be  considered  as  associated  with  these  diabase  eruptions.  It 
is  true  also,  as  already  seen,  that  Hussak  demands  for  the  Passagem 
lode  an  igneous  origin. 

Nothing  is  at  present  known  of  the  geological  relations  of  the 
auriferous  schists  of  Southern  Chili  and  of  Tierra  del  Fuego. 

New  Zealand. — Another  ancient  schistose  area  in  which 
igneous  intrusions  have  not  been  found  occurs  in  the  Otago  province, 
South  Island  of  New  Zealand.  While  numerous  gold  veins  have 
been  worked  in  these  rocks,  their  importance  arises  from  the  fact 
that  they  have  furnished  the  great  alluvial  auriferous  deposits  of 

aZeit.  fur   Prakt.    Geol,    Oct.,    1898,   p.    395. 

b  Trans.  Amer.  Inst.  M.E.,  XXXIII,  1903,  p.  283. 

cLindgren,    Econ.    Geol.,    I,    1905,   p.    163. 

d  Derby,  loc.  cit,,  p.  284. 

e  But  see  in  this  connection  Orville  Derby,  Amer.  Jour.  Sci.,  XI.  1901,  p.  34. 

/Berg,  Zeit.  fur  Prakt,   Geol.,   1902,  p.   82. 


54  AURIFEROUS    PROVINCES. 

Otago.  These  schists  are  obviously  of  sedimentary  origin,  and  range 
from  phyllites  to  chlorite-  and  quartz-schists. a  There  is  no  direct 
internal  evidence  of  their  age,  but  they  are  probably  very  much 
younger  than  Archaean.  They  are  even  ascribed  to  the  Carboni- 
ferous or  Devonian.6  While  there  is  a  possibility  that  these 
schists  have  obtained  their  vein-gold  by  lateral  secretion  from 
contemporaneously  deposited  alluvial  gold,  there  is  yet  reason  to 
believe  that  auriferous  deposition  in  Otago,  as  on  the  West 
Coast  of  New  Zealand,  may  be  genetically  connected  with  the 
granite  rocks  intruded  during  the  Middle  Mesozoic  uplift  of  the 
Southern  Alps.  Other  auriferous  schists  of  indefinite  age  and  of 
as  yet  unknown  relations  are  those  furnishing  the  placer  deposits 
of  Alaska  and  of  Eastern  Siberia. 

PRE-CAMBRIAN   GROUP. 

The  auriferous  deposits  to  be  grouped  under  this  head  are 
nearly  all  contained  in  the  Archaean  schists  already  described.  In 
all  cases  it  would  appear  that  the  auriferous  solutions  have  been  set 
in  circulation  by  diabasic  flows  and  intrusions,  but  not  even  a  guess 
may  be  made  as  to  whether  the  gold  was  brought  to  its  present 
position  by  the  uprising  diabasic  magma  or  whether  the  diabasic  and 
dioritic  intrusions  found  the  schists  already  auriferous  and  served 
only  as  carriers  of  heat  and  of  solvent  vapours.  While  the  deposits 
are  generally  contained  within  the  Archaean  schists,  notable  excep- 
tions, as  in  Western  Australia  (Nullagine)  and  South  Africa  (Wit- 
watersrand),  occur  when  younger  porous  strata,  as  conglomerates, 
offer  ready  passage  to  the  auriferous  solutions.  Following  the 
order  adopted  in  the  preceding  section,  the  Indian  occurrences  will 
first  be  detailed. 

India. — Throughout  the  whole  Dharwarian  Series,  as  well  as 
through  the  adjacent  crystalline  rocks,  there  ramify  numerous 
diabasic  and  doleritic  dykes,  that,  showing  no  schistose  structure 
and  no  trace  whatever  of  deformation,  are  certainly  later  than  the 
period  of  the  final  metamorphism  of  the  enclosing  rock.  These 
dykes  are  to  be  correlated  with  certain  lava  flows  in  the  Cheyair 
group  of  the  Lower  Cuddapah  system. 

The  Cuddapahs  are  unfossiliferous,  and  little  evidence  is 
available  to  indicate  their  exact  stratigraphical  position.  They  are, 
however,  generally  considered  to  be  Pre-Cambrian,  and  hence  this  age 
must  also  be  assigned  to  the  great  diabasic  outburst  which  set 
auriferous   solutions  once  more  circulating  through  the  long-closed 

aHutton,  Trans.  N.Z.  Inst.,  XXIV,  1891,  p.  359. 
h  Park,  Bull.   Xo.   5,  N.Z.   Geo!.  Surv.,   1908,  p.  28. 


INDIA.  55 

waterways  of  the  Dharwars.  Veins  of  Pre-Cambrian  age  occur  mainly 
in  argillites  and  chloritic  schists.  They  are  best  exemplified  in  the 
Gadag  belt  and  the  Dharwar  belt  proper,  and  are  characterised 
by  a  white  quartz  and  a  disposition  of  the  veins  in  accordance  with 
the  foliation  of  the  country.  The  quartz  lenses  in  the  Gadag  area 
are  often  connected  by  graphitic  lode-formations,  and  the  main 
Gadag  reef  system  lies  within  a  highly  carbonaceous  band  in  the 
argillites.  In  many  cases,  as  at  Kolar  and  at  Hutti  (Nizam's 
Dominions),  the  older  Archaean  fissures  were  re-opened,  and  we 
thus  find  the  older  blue  and  the  younger  white  quartz  lying  side  by 
side  in  the  same  fissure.  The  blue  quartz  has  already  been  seen 
to  show  under  the  microscope  evidences  of  considerable  dynamic 
pressure.  The  white  quartz,  on  the  other  hand,  shows,  in  thin 
sections,  no  trace  of  schistose  structure  and  no  further  strain 
phenomena  than  are  normal  in  the  quartz  of  undisturbed  veins.  The 
auriferous  veins  of  Chota  Nagpur,  the  northern  Dharwar  area  of 
India,  are,  so  far  as  they  have  been  examined,  small  and  poor.  They, 
however,  fall  in  this  division,  and  are  to  be  associated  with  a  great 
dioritic  dyke  very  similar  to  those  already  described,  and  which, 
known  as  the  Dulma  Trap,  sweeps  in  an  arc  of  a  circle  through 
the  Singhbhum  Division. a 

Western  Australia. — In  Western  Australia  the  same  general 
stratigraphical  conditions  obtain  as  in  India.  There  also  the  green- 
stone schists  are  intruded  by  numerous,  often  parallel,  diabasic  and 
doleritic  dykes.  These,  as  in  India,  are  generally  vertical  or  nearly 
so.  In  addition  to  the  basic  intrusions,  there  are  also  found  a  great 
number  of  acidic  dykes  which  may  be  regarded  as  apophyses  from 
the  younger  granites,  and  which  range  from  granites  through 
aplites  to  a  rock  which  may  almost  be  termed  a  quartz  vein.^  It 
is  of  considerable  importance  to  note  that  these  acidic  dykes  are 
themselves  barren,  and  that  they  appear  to  have  had  no  effect 
whatever  on  auriferous  deposition.  In  the  Pilbara  goldfield,  a 
northern  district,  and  one  displaying  the"  most  instructive  section 
of  all  the  West  Australian  goldfields,  the  steeply-inclined  schists 
are  overlain  by  a  fairly  horizontal  series  of  sandstones,  grits, 
conglomerates,  and  thin  limestones  associated  with  amygdaloidal 
diabases  and  felsites,  as  their  basal  members.0  To  this  series 
the  term  Nullagine  Beds  has  been  given.  The  presence  of  the 
amygdaloidal  diabase  may  afford  a  clue  to  the  age  of  the 
basic  intrusive  dykes  of  the  "  Auriferous  Series."  The  mineralising 
influence  of  the  diabasic  dykes  is  well  marked  on  the  northern  gold- 


aMaclaren,   Rec.   Geol.   Surv.   India,   XXXI,    1905,   p.    74. 
h  Jackson,  W.A.  Geol.  Surv.,  Bui!.  3,  p.  21. 
cMaitland,  W.A.  Geol.  Surv.,  Bull.   15,    1904. 


56  AURIFEROUS   PROVINCES. 

fields,  where  the  characteristic  laminated  hsematite-magnetite- 
quartz  rocks  are  extensively  developed.  These  latter  are  not 
innately  auriferous,  and  it  is  only  where  they  are  crossed  by  basic 
dykes,  by  faults,  or  by  cross  veins,  that  they  carry  gold,  and  then 
only  for  a  few  feet  on  either  side  of  the  intersection,  forming 
narrow  "  shoots  "  in  the  quartzite  bands.a 

The  white  quartz  veins  of  these  fields  are  also  apparently  to  be 
connected  with  the  diabasic  intrusions,  since,  like  them,  they  cut 
through  and  mineralize  many  of  the  laminated  quartzites. &  To 
the  same  age  and  to  the  same  influence  may  perhaps  be  assigned 
the  auriferous  character  of  the  conglomerates  of  the  Nullagine 
district.  These  apparently  furnish  a  very  close  parallel  in  mode  of 
formation  to  the  famous  banket  reefs  of  the  Rand.  They  have 
been  described  by  Maitlandc  as  forming  the  Mosquito  Creek  Beds 
towards,  or  at  the  base  of,  the  Nullagine  Series.  The  auriferous 
conglomerates  occur  in  lenticular  masses  and  contain  gold  both  in 
thin  white  quartz  veins  which  are  parallel  with  the  bedding  planes, 
and  also  interspersed  through  the  matrix  of  the  conglomerate.  The 
veins,  as  might  be  expected,  are  much  richer  than  the  conglomerate 
matrix,  the  former  averaging  2-82  ozs.  and  the  latter  only  .62 
ozs.  per  ton. 

South  Africa. — In  South  Africa,  numerous  diabasic  dykes 
break  through  the  Barberton  Series,  and  some  of  these  have,  at 
Barberton  itself,  exercised  a  notable  influence  on  auriferous  de- 
position, furnishing  in  the  Barberton  laminated  quartzites  well- 
marked  "  shoots  " d  akin  to  those  of  Western  Australia.  To  this 
period  of  auriferous,  activity  we  may  now  reasonably  ascribe  the 
infiltration  and  auriferous  impregnation  of  the  Rand  '  banket." 
The  stratigraphy  of  the  Witwatersrand  series  has  been  fully 
discussed/  Excepting  that  they  are  much  younger  than  the  Swazi- 
land schists  and  older  than  the  Devonian  rocks  of  the  Cape  System, 
little  can  be  said  of  their  geological  horizon.  The  Rand  Beds  con- 
sist, briefly,  of  quartzites,  slates,  and  conglomerates.  Of  these,  the 
striped  and  contorted  bands,  in  the  Hospital  Hill  Beds,  of  alternating 
layers  of  jasper,  quartz,  specular  iron,  and  magnetite  f  are  strongly 
reminiscent  of  similar  beds  in  the  Pre-Cambrian  Bijawars  of  India. 
In  the  present  connection,  however,  by  far  the  most  important 
geological  feature  is  the  occurrence  of    numerous   uralitic  diabase 

aMaitland,  Ann.  Rep.  W.  A.  Geo].   Surv.,  1903,  p.  10. 

b  Idem,  loc.  cit.,  1902,  p.  16. 

c  Report  quoted  Aust.  Mining  Standard,  Oct.  25,  1905,  p.  399. 

d  Trans.  Geol.  Soc.  S.A.,  VI,  Pt.  I,  1904,  p.  56. 

e  Hatch  and  Corstorphine,  "  Geology  of  South  Africa,"  London,  1905. 

/"Hatch  and  Corstorphine,  Trans.  Geol.  Soc.  S.A.,  VII,  1905,  p.  98. 


TRANSVAAL.  5/ 

dykes  ramifying  throughout  the  auriferous  series,  and  of  sheets 
of  diabase,  often  amygdaloidal,  which  occur  at  various  horizons  in 
the  system,  and  are  especially  well  developed  in  the  Eastern  Rand. 
The  period  of  auriferous  infiltration  of  the  Witwatersrand  System 
would  seem  to  be  very  definitely  limited  by  the  occurrence  in  the 
overlying  Ventersdorp  System  of  occasionally  auriferous  conglo- 
merate boulders  "  unmistakably  derived  from  the  Witwatersrand 
Beds.""  There  is,  as  already  stated,  at  present  no  evidence  to  indicate 
whether  the  gold  of  the  auriferous  solutions  was  derived  from  the 
diabasic  magma  or  was  dissolved  from  the  presumably  underlying 
Archaean  schists  such  as  those  already  described  as  occurring  close 
to  the  Rand  in  the  Bezuidenhout  Valley.  The  latter  assumption 
is  considered  the  more  probable,  but  the  question  must  remain  an 
academic  one  until  assays  for  minute  quantities  of  gold  in  the  dia- 
bases of  the  area  have  been  made.  Even  then,  absence  of  gold  from 
fresh  diabase  will  not  conclusively  prove  that  they  were  not 
accompanied  by  auriferous  solutions. 

Corroborative  evidence  of  the  close  genetic  relation  existing  in 
the  Transvaal  region  between  diabasic  intrusions  and  auriferous 
deposition  is  furnished  by  the  Lydenburg  and  other  goldfields  lying 
along  the  eastern  escarpment  of  the  High  Veld.  Here  diabase 
sills  have  been  intruded  along  the  almost  horizontal  bedding  planes 
of  the  sedimentary  rocks  (mainly  dolomite).  Siliceous  solutions, 
apparently  set  in  circulation  by  the  igneous  intrusions,  have,  along 
flat  fissures  in  the  neighbourhood  of  the  diabase  sheets,  acted  on  and 
metasomatically  replaced  the  calcareous  rock,  with  attendant 
deposition  of  gold. 

In  Egypt  also,  an  area  which  may  be  regarded  as  furnishing 
the  most  northerly  portion  of  the  East  African  Archaean  band,  there 
is  an  apparent,  though  not  a  certain  connection  between  Pre- 
Cambrian  diabasic  or  dioritic  intrusions  and  auriferous  deposition. 
The  little  evidence  available  regarding  the  gold-deposits  of  West 
Africa  hardly  permits  of  speculation. 

America. — Turning  now  to  the  Archaean  schists  of  Eastern 
America,  we  are  confronted  with  identical  phenomena.  Dykes  of 
diabase,  little,  if  at  all  metamorphosed,  are  present  in  some  of  the 
gold-mining  districts  of  North  Carolina,  and  have  obviously  had 
a  considerable  influence  on  ore-deposition.  In  South  Carolina, 
the  Haile  is  one  of  the  best-known  mines.  The  country  rock  is 
a  muscovite-schist  that,  according  to  Becker, &  is  an  altered  Archaean 
volcanic  rock.  It  is  intruded  by  numerous  diabase  dykes,  which 
cut  through  the  rock  without  any  apparent  dislocation.     For  some 

aLoo.  cit.  sup.,  p.  149. 

6  16th  Ann.  Rep.   U.S.  Geol.  Surv.,  Pt.  Ill,  1895,  p.  262. 


58  AURIFEROUS    PROVINCES. 

distance  from  the  dykes,  the  muscovite-schist  has  been  very  com- 
pletely metamorphosed.  The  metamorphosed  zones  have  been 
thoroughly  impregnated  with  auriferous  pyrites,  which  sometimes 
forms  layers,  4  inches  to  6  inches  thick,  along  the  surfaces  of  contact. 
Mining  is  carried  on  in  the  impregnated  schists,  the  only  defined 
boundary  of  the  deposit  being  formed  by  the  dyke,  whilst  the 
thickness  of  the  deposit  is  determined  solely  by  its  economic  value, 
since  it  is  worked  only  as  far  from  the  dyke  as  can  be  done  with 
profit.  The  Brewer  mine,  a  few  miles  away,  has  a  similar  wall  rock. 
Lindgren,"  however,  points  out  that  the  auriferous  veins  of  Dahlonega, 
Ga.,  are  in  genetic  connection,  not  with  diabase,  but  with  acid 
aplitic  intrusive  rocks.  It  would  therefore  appear  that  the  heat 
of  the  igneous  rock,  rather  than  the  nature  of  the  igneous  rock 
itself,  has  been  the  controlling  factor  in  the  formation  of  gold- 
deposits  of  this  type. 

Ontario. — In  the  Lake  of  the  Woods  region,  Ontario,  which  may 
be  regarded  as  the  most  northerly  extension  of  the  Appalachian 
belt,  diabase  dykes  in  a  greenstone-  or  diabase-schist  are  found 
intimately  connected  with  the  origin,  if  not  with  the  mineral  contents, 
of  some  of  the  veins. & 

Colorado. — The  Pre-Cambrian  schists  of  the  Gunnison  gold 
belt,  Colorado,  are  hornblendic  rather  than  micaceous.  They  are 
occasionally  penetrated  by  dykes  of  dark  diabase.0 

Nova  Scotia. — These  goldfields  have  been  tentatively  grouped 
by  Lindgren  with  the  Archaean  Appalachian  schist  deposits  already 
described,  but  a  consideration  of  their  relations  seems  to  bring 
them  most  naturally  to  this  place.  The  auriferous  sedimentary  rocks 
are  highly  pyritous  slates  and  quartzites,  sandstones,  and  con- 
glomerates. Gold-quartz  veins  also  occur  in  the  older  schist 
further  east,  near  Bras  d'Or  Lake,  Cape  Breton  Island.  Their 
age  is  not  clear,  and  may  be  Cambrian  or  even  Pre-Cambrian. 
From  the  occurrence  of  auriferous  quartz  pebbles  in  a  Lower 
Carboniferous  conglomerate,  mineralisation  is  believed  to  have 
taken  place  prior  to  that  period.  The  sedimentary  rocks  are  every- 
where intruded  by  granite,  and  this  rock  constitutes  much  of  the 
surface  of  the  auriferous  area.  Occasional  fissure  veins  are  met 
with,  but  the  general  type  of  vein  is  one  that  closely  follows  the 
foldings  of  the  slates  and,  indeed,  resembles  closely  the 
'saddle  reefs"   of  Bendigo.     The  gangue  is   quartz  with  a  little 

"Bull.  U.S.  Geol.  Surv.,  Xo.  293,  1906,  p.  124. 
h  Trans.  Am.  Inst.  M.E.,  XXVI,  1896,  p.  850. 
cIb.,  p.  440. 


GUI  AX  AS.  59 

calcite.     The  veins  contain  auriferous  pyrites,  mispickel,  and  rarely 
galena  and  blende. 

Guianas. — A  well-defined  auriferous  province  extends  from 
the  Yaruari  basin,  immediately  south  of  the  Orinoco  river  in 
Venezuelan  Guiana,  through  British,  Dutch,  and  French  Guiana 
to  the  "  Disputed  Territory  "  of  Brazil,  lying  north  of  the  Amazon. 
Owing  probably  to  the  unhealthiness  of  the  country  and  to  the 
dense  jungle  with  which  the  region  is  covered,  few  gold-quartz  veins 
of  importance  are  known.  El  Callao  in  Venezuela,  and  the  Peters 
mine  in  British  Guiana  are  the  only  two  of  economic  value.  The 
placer  deposits  of  the  region,  however,  furnish  considerable  quan- 
tities of  gold.  Everywhere  throughout  this  territory  auriferous 
deposition  in  situ  has  shown  a  marked  dependence  on  diabasic 
and  dioritic  intrusions,  and  in  many  cases  the  igneous  rocks  them- 
selves have  been  proved  to  be  slightly  auriferous,  though  it  is 
not  clear  whether  the  gold  thus  found  is  authigenic  or  has  been 
introduced  in  association  with  pyrite  at  a  later  date. 


TERTIARY    AXDESITIC    GOLDFIELDS. 

All  the  goldfields  to  be  considered  under  this  head  lie  either 
in  andesite  rocks  or  in  rocks  very  closely  allied  genetically  and 
petrographically  to  normal  basic  (augitic)  andesites,  or  else  in 
igneous  or  sedimentarv  rocks  in  the  vicinity  of  such  andesitic 
intrusions.  Their  range  petrologically  may  include  rocks  as  acid 
as  quartz-trachytes,  and  the  term  andesitic  is  selected  merely 
as  denoting  the  general  type.  The  range  in  geological  time  is  from 
Eocene  to  Pliocene  with  a  special,  though  perhaps  merely  coin- 
cidental, development  in  the  Oligocene  and  Miocene.  A  glance 
at  the  world's  andesitic  goldfields  will  show  how  remarkably 
closely  they  follow  the  existing  lines  of -volcanic  activity  on  the 
earth's  surface  ;  the  "  Pacific  Circle  of  Fire  '  is  likewise  a  circle 
of  andesitic  goldfields.  Andesitic  goldfields  are  sporadically  dis- 
tributed from  Valparaiso  northwards  through  the  Andes  ;  they 
attain  extraordinary  richness  in  Mexico  and  the  Western  States 
of  America,  and  especially  in  Xevada,  Utah,  and  Colorado.  A 
break  occurs  in  British  Columbia,  but  the  line  is  again  taken  up  on 
Unga  Island  in  Alaska."  In  the  Western  Pacific,  the  corresponding 
line  is  run  by  the  extensive  andesitic  goldfields  of  Japan,  through 
similar  fields  in  Sumatra  and   Celebes.6 

ftLindgren,  Trans.  Amer.  Inst.  M.E.,  XXXIII,  p.  806. 
^Truscott,  Trans.  Inst.  Min.  Met..  X.  p.  52-73. 


60  AURIFEROUS    PROVINCES. 

The  auriferous  andesitic  occurrences  of  Kyoukpazat  in  Burma 
and  of  Talan,  in  Yunnan,  are  to  be  regarded  as  sporadic  along 
meridional  lines  of  Miocene  folding  that  are  parallel  with,  or  only 
slightly  divergent  from,  the  main  direction  of  the  lines  of  crustal 
weakness  passing  from  Formosa  to  Borneo. 

The  rich  andesitic  goldfield  of  New  Zealand  may  be  considered 
to  mark  the  southern  limit  of  the  chain  of  goldfields  in  the  Western 
Pacific.  The  rare  occurrences  of  gold  in  the  Fiji  Islands  may  also 
owe  their  origin  to  Tertiary  andesitic  influences.  All  the  world's 
andesitic  goldfields,  with  one  notable  exception,  are  on  the  "  circle." 
The  exception  is  the  Transylvanian  and  similar  Hungarian  gold- 
fields  ;  their  andesites,  erupted  during  the  Aquitanian  stage,  are 
clearly  to  be  referred  to  the  lines  of  crustal  weakness  first  developed 
in  Southern  Europe  in  the  Oligocene,  and  now  indicated  by  the 
active  volcanoes  of  the  Mediterranean.  The  outstanding  features 
of  the  andesitic  type  of  goldfield  are  therefore  its  modernity  and  its 
consequent  direct  connection  with  existing  volcanic  phenomena. 

All  andesitic  goldfields  present  a  well-defined  and  uniform 
facies.  The  andesite  or  allied  rock  has,  under  the  influence  of 
solfataric  agencies,  and  by  the  breaking  up  of  its  felspars  and  ferro- 
magnesian  silicates,  been  converted  to  "  propylite,"  in  which  the 
ferro-magnesian  silicates  have  given  place  to  chlorite  and  epidote, 
and  the  felspars  to  quartz,  chlorite,  and  epidote. 

It  has  generally  been  assumed  that  solfataric  action  is  an 
end-product  of  volcanic  energy  ;  while  this  may  be,  and  probably 
is  true  for  local  outbursts,  it  is  certainly  not  so  when  the  whole 
Tertiary  field  of  vulcanism  is  considered,  for  solfataric  action  can 
be  shown  to  have  persisted  concomitantly  with  the  effusion  of  lavas, 
whether  of  normal  or  of  extreme  types.  From  our  present  point 
of  view,  however,  the  only  important  solfataric  action  has  been 
that  which  succeeded  the  extrusion  of  the  augite-andesite  lavas, 
and  this,  so  far  from  occurring  towards  the  end  of  the  period  of 
volcanic  activity,  took  place  relatively  soon  after  the  commence- 
ment. There,  therefore,  lies  in  this  feature  a  weighty  objection  to 
the  hypothesis  of  J.  E.  Spurr,a  in  which  highly  siliceous  solutions 
(forming  quartz  veins)  and  metalliferous  solutions  (furnishing  the 
filling  of  the  quartz  veins)  are  considered  the  end-products  of  the 
segregation  of  magmas  within  the  earth's  interior.  While  auriferous 
deposition  would  appear  to  have  been  most  wide-spread  in  Miocene 
time,  the  solfataric  action  that  contributed  towards  it  existed  before 
that  period  and  has  persisted  to  the  present  day,  as  is  evidenced 
by  the  metalliferous  deposits  of  the  Steamboat  Springs  in  Nevada, 

a  Econ.  Geol.,  II,  1907,  p.  781. 


ANDESITIC    FIELDS.  61 

and  by  the  auriferous  deposits  of  the  geysers  of  New  Zealand,0 
both  occurrences  being  in  well  propylitised  andesitic  provinces, 
with  andesite  lavas  at  least  as  old  as  the  Miocene  period. 

The  matrix  of  the  gold  of  the  andesitic  fields  is  generally 
quartz.  The  bullion  is  invariably,  when  of  primary  deposition, 
of  low  grade,  and,  especially  when  associated  with  calcite  in  veins, 
is  often  crystallized.  Tellurides  of  gold  and  silver,  though  not 
restricted  to  the  andesitic  goldfields,  are  characteristic  of  them.  The 
associates  of  the  gold  in  rude  order  of  value  as  "  indicators  "  are  :  — 
galena,  stibnite,  argentite,  stephanite,  proustite,  pyrargyrite, 
chalcopyrite,  nagyagite,  sylvanite,  native  arsenic,  pyrite,  and, 
more  rarely,  zinc  blende,  grey  copper,  bournonite,  realgar,  and 
orpiment.  Andesitic  goldfields,  as  a  rule  (to  which  there  are, 
however,  several  notable  exceptions),  are  characterised  by  the 
irregularity  of  the  gold-veins  both  in  value  and  in  extent,  the 
economic  value  often  depending  entirely  on  very  local  enrichments. 

The  general  distribution  of  the  andesitic  goldfields  may  be 
considered  in  detail,  and  a  few  of  the  more  important  selected  for 
description  as  typical.  The  coincidence  of  these  goldfields  with 
the  lines  of  volcanic  activity  that  border  the  Pacific  Ocean  has 
already  been  indicated.  Assuming  for  the  moment  that  auriferous 
solutions  are  a  product  of  andesitic  magmas,  as  the  general  connection 
might  well  indicate,  it  is  difficult  to  account  for  the  sporadic  and 
irregular  distribution  of  goldfields  within  andesitic  zones.  A 
consideration  of  the  regional  distribution  of  andesitic  goldfields 
and  of  more  ancient  auriferous  deposits  suggests  two  alternative 
inferences  ;  either  that  auriferous  andesites  may  themselves  be  a 
rechauffee  of  older  auriferous  rocks,  metamorphic  or  sedimentary  ; 
or  that  they  may  have  obtained  their  gold  during  the  passage  of 
their  solfataric  waters  through  older  auriferous  rocks.  In  either  case 
the  gold  cannot  be  considered  of  direct  magmatic  origin,  and 
andesites,  under  such  an  assumption,  are  auriferous  only  when 
underlying  or  adjacent  rocks  have  carried  gold.  From  this  point 
of  view,  therefore,  andesitic  magmas  are  to  be  regarded  merely 
as  heat  carriers. 

South  America. — To  the  southward  range  of  these  fields  along 
the  Andes  of  South  America  it  is  impossible  to  place  any  definite 
limit ;  they  appear  to  reach  at  least  as  far  south  as  the  latitude  of  Val- 
paraiso (33°S. Lat.).  The  associated  rocks  are  there,  however,  liparitic 
(rhyolitic)  rather  than  andesitic.  To  the  north,  in  Peru  and  Ecuador, 
and  to  a  lesser  degree  in  Colombia,  the  goldfields  are  widely  scattered 
and  the  veins  are  .notable  for  their  silver  content  rather  than  for 
their  gold.      In  any  case  little   definite   geological  information   is 

a  Maclaren,  Geol.  Mag.,  Dec.  5,  III,  1906,  p.  514. 


02  AURIFEROUS    PROVINCES. 

available  concerning  them.  Perhaps  the  first  of  the  typical  andesite 
fields  reached  proceeding  northwards  is  the  formerly  world-famed 
Espritu  Santo  mine,  in  the  Isthmus  of  Darien. 

Numerous  veins  occur  in  the  western  portions  of  the  Central 
American  republics  of  Panama,  Costa  Rica,  Nicaragua,  Salvador, 
and  Guatemala. 

North  America.— It  is  in  the  great  Miocene  petrographical 
province  mentioned  as  ranging  northward  through  Western  North 
America  from  Mexico  that  auriferous  andesitic  veins  attain  their 
greatest  development.  Of  the  great  number  of  goldfields  in  these 
rocks,  three  fairly  typical  areas  :  Pachuca  in  Mexico,  Comstock  in 
Nevada,  and  Cripple  Creek  in  Colorado,  may  briefly  be  described. 

Paehuca. — The  Sierra  Pachuca  lies  to  the  north-east  of  the 
City  of  Mexico.  The  basement  rocks  are  non-fossiliferous  Cretaceous 
sediments  which,  during  the  Middle  Tertiary,  were  broken  and 
upheaved  by  tectonic  disturbances,  and  were  covered  by  andesites 
and  dacites,  with  tuffs  and  breccias,  rhyolites,  and  finally,  basalts. 
The  andesites  are  mainly  pyroxenic,  and  are  sometimes  diabasic.a 
It  is  in  the  andesitic  rocks  alone  that  the  metalliferous  veins  are 
developed.  The  gangue  is  quartz  with  occasional  later  and  subor- 
dinate calcite,  rhodonite,  and  rhodochrosite.  The  associates  of 
the  gold  are  argentite,  pyrite,  galena,  zinc  blende,  stephanite, 
and  polybasite.  The  country  rock  here,  as  in  all  auriferous  andesitic 
areas  that  have  undergone  propylitization,  contains  much  secondary 
pyrite,  while,  near  the  vein,  the  country  is  generally  much  silicified. 
The  characteristic  "shoots"  or  "bonanzas"  furnish  most  of  the 
product  of  Pachuca.  The  yield  is  mainly  in  silver,  only  20  to  30 
per  cent,  of  the  value  being  in  gold. 

Northward,  the  chain  of  andesitic  fields  is  prolonged  through 
New  Mexico  to  Colorado,  where  they  are  widely  developed,  and 
through  Arizona  to  Nevada  and  Utah  as  far  north  indeed  as  Silver 
City  in  Idaho.  Sporadic  fields  occur  further  north,  as  at  Monte 
Christo  in  Washington,  which  with  the  possible  exception  of  the 
Rossland  sulphide  occurrences,  probably  also  to  be  referred  to  this 
period,  are  the  most  northerly  of  the  Tertiary  andesitic  fields  on 
the  eastern  seaboard  of  the  Pacific  Ocean. 

Comstock,  Nevada. — Ancient  metamorphic  slates  occur  in  the 
southern  portion  of  the  district,  and,  indeed,  form  the  foot  wall  of 
the  Comstock  lode  south  of  the  Yellow  Jacket  and  Belcher  shafts, 
but  the  mass  of  the  country  rock  is  igneous  and  andesitic.  According 
to  Hague  and  Iddings,&  the  order  of  succession  of  the  rocks  of  the 

a  Aguilera  and  Ordonez,  Boletin  del  Institut.  de  Mexico,  Nos.  7,  8,  9,  1897. 
b  Bull.,  U.S.  Geol.  Surv.,  No.  17,  1885,  p.  123. 


CRIPPLE    CREEK.  63 

district  is  andesite,  dacite,  rhyolite,  andesite,  and  basalt.  In 
depth  the  andesites  assume  a  dioritic  and  diabasic  habit.  Propy- 
litization  is  extensive — the  hornblende,  augite,  and  biotite  yielding 
chlorite,  epidote,  and  pyrite,  while  the  felspars  furnish  quartz 
and  a  white,  possibly  sericitic,  material. 

The  lode  is  3  to  4  miles  in  length.  The  product  was  mainly 
silver  obtained  from  stephanite,  argentite,  and  polybasite.  Galena 
and  zinc  blende  also  occur.  The  bullion  contains  6  to  7  per  cent, 
of  gold,  or  about  half  the  value.  The  matrix  is  quartz  with  occasional 
calcite.  Bonanzas  have  furnished  the  greater  portion  of  the 
product.   L Pyrite  is  abundantly  scattered  through  the  country  rock. 

Cripple  Creek,  Colorado. — This  field  lies  in  the  Eastern 
Rocky  Mountains,  about  10  miles  south-west  of  the  famous  Pike's 
Peak.  Its  country  rock  is  the  red  granite  of  that  mountain.  The 
granite  contains  occasional  Pre-Cambrian  schists  seamed  with  diabase 
dykes.  The  auriferous  area  is,  however,  some  20  square  miles  of 
Oligocene  or  Miocene  volcanic  rocks.  The  earliest  eruptions  and 
the  most  extensive  were  andesitic,  and  occur  both  as  lavas  and  as 
tuffs  and  breccias,  the  latter  predominating.  Following  the  andesites 
came  phonolitic  breccias  and  dykes,  with  which  may  be  associated 
some  minor  outcrops  of  syenite  and  nepheline  syenite.  Finally, 
these  were  intruded  by  more  basic  rocks,  yielding  dykes  of  nepheline- 
basalt,  felspar-basalt,  and  limburgite.a  Hydrothermal  agencies 
have  been  extremely  active  in  the  region,  and  the  breccias  are  often 
so  highly  dolomitised  that  little  of  their  original  character  can  be 
discerned. 

The  veins  are  very  largely  replacement  veins,  and,  probably 
owing  to  the  presence  of  the  phonolitic  magma,  show  a  divergence 
from  the  vein  association  usual  in  andesitic  areas,  viz.,  in  the 
occurrence  of  fluorite.  This  mineral,  together  with  secondary 
orthoclase  (adularia  or  valencianite),  occurs  abundantly  in  the  veins, 
and  also  as  an  impregnation  in  the  surrounding  country  rock. 
The  ordinary  gangue  is  quartz,  but  barytes  also  occurs.  Opaline 
silica  is  occasionally  met  with.  The  veins  persist  into  the  granite, 
in  which  rock  also  alteration  has  proceeded  outward  from  the  vein, 
resulting  often  in  the  production  of  a  highly  cellular  rock.  The 
cavernous  rock  and  the  porous  breccias  may  be  impregnated  for 
several  feet  with  auriferous  tellurides,  fluorite,  and  secondary 
orthoclase,  and  it  is  these  telluride  replacements  rather  than  the 
quartz-veins  themselves  that  furnish  the  bulk  of  the  Cripple  Creek 
gold.  The  tellurides  are  principally  calaverite,  krennerite,  and 
sylvanite,    with   rare   petzite.      Other   associates   of   the   gold   are 


a  Penrose,  16th  Ann.  Rep.,  U.S.  Geol.  Surv.,  II,  1895. 


64  AURIFEEOUS    PROVINCES. 

galena,  chalcocite,  stibnite,   and    zinc-blende.      The    general    dis- 
position of  the  ore-bodies  is  in  thin  shoots. 

Similar  districts  in  the  Western  States  of  America  are  Silver 
City  and  De  Lamar,  Idaho  a  and  Goldfield,  Rhyolite,  and  Tonopah, 
Nevada.6  These  and  others  will  be  found  more  fully  described 
in  later  sections  of  this  volume. 

Connection  is  made  between  North  America  and  Asia  by  the 
islands  of  the  Aleutian  chain.  Many  of  these  possess  still  active 
volcanoes.  Gold  deposits  of  the  normal  andesitic  type  also  occur, 
but  these  have  not  hitherto  proved  of  great  importance.  The  line 
of  volcanic  manifestation  runs  from  the  Aleutian  chain  to  Japan 
by  way  of  the  Kurile  Islands.  In  Japan  there  are  many  gold  areas 
scattered  through  andesitic  rocks.  They  are  not  now  highly  pro- 
ductive, but  the  upper  zones  of  their  veins  furnished  many  million 
ounces  during  the  15th  and  16th  centuries  to  Portuguese  and 
Dutch  merchants.  The  goldfields  of  northern  Formosa  are  a  direct 
continuation  of  the  Japanese  chain.  South  of  Formosa  andesitic 
goldfields  appear  to  be  connected  with  another  zone  of  crustal  weak- 
ness running  almost  at  right  angles  to  the  Japanese  line.  The  gold 
occurrences  of  the  Philippines  are  mainly  in  older  rocks,  and  no 
direct  evidence  is  there  available  of  association  with  Tertiary 
intrusives. 

A  great  andesitic  zone  runs  through  the  East  Indian  Archipelago. 
Its  most  northerly  fields  are  doubtfully  those  of  Kyoukpazat  in 
Burma  and  Talan  in  Yunnan,  which  are  developed  along  meridional 
lines  of  Miocene  crustal  weakness,  but  the  first  important  goldfields 
are  those  of  Central  and  Southern  Sumatra,  the  last  containing 
the  well-known  Radjang  Lebong  mine.  From  thence  the  belt 
appears  to  run  eastward  equatorially,  including  the  goldfields  of 
Bau  and  Bidi,  Sarawak,  and  others  in  Southern  Borneo,  and  ends 
in  the  scattered  goldfields  of  the  eastward  prolongation  of  Northern 
Celebes.  The  general  relations  of  the  Japanese,  Asian,  and  Archi- 
pelagian  goldfields  are  not  now  evident,  and  will  be  understood  only 
with  fuller  geo-tectonic  information  concerning  south-eastern  Asia. 

New  Zealand. — The  New  Zealand  auriferous  andesitic  area 
in  the  Hauraki  Peninsula  is  only  broadly  connected  with  the  fore- 
going ;  its  position  appears  to  have  been  determined  by  the  inter- 
section of  two  of  the  great  Pacific  axes  of  folding  and  faulting — 
one  running  south-west  to  form  the  mountain  chain  of  New  Zealand, 
and  north-east  into  the  Central  Pacific  Ocean,  where,  along  its 
course,  several  active  volcanoes   (Kermadecs,   Tofoa,  Savaii,   &c.) 


"  Lindgren,  20th.  Ann.  Rep.,  U.S.  Geol.  Surv.,  pp.  107-188. 
*'  Spurr,  U.S.  Geol.  Surv.,  Prof.  Paper,  No.  42,  1905. 


NEW   ZEALAND.  65 

have  been  developed  ;  the  other  axis  strikes  north-west  through 
Norfolk  Island  to  New  Caledonia  and  the  New  Hebrides.  At  the 
intersection  of  these  axes  volcanic  activity  is  still  extant,  and  is 
manifested  by  the  eruptions  and  geysers  of  the  Hot  Lakes  region. 

The  Tertiary  eruptives  of  the  Hauraki  Peninsula  rest  on 
sediments  of  obscure  Mesozoic  and  Palaeozoic  age.  The 
oldest  of  the  eruptives  are  Upper  Eocene  in  age  and  are  flows 
and  breccias  of  andesites  (pyroxenic  in  the  main,  occasionally  hyper- 
sthenic, but  sometimes  amphibolitic)  and  dacites  that  are  mainly 
hornblendic.  This  series  contains  the  auriferous  veins.  It  was 
succeeded  by  a  well-differentiated  Oligocene  or  Miocene  series  (Beeson 
Island  Group)  consisting  mainly  of  coarse,  somewhat  trachytic 
breccias.  Under  the  microscope,  they  are,  as  has  been  shown  by 
Professor  Sollas,a  mainly  hypersthene-andesites  and  dacites,  though 
many  of  the  latter,  especially  when  hornblendic,  might  readily 
be  termed  trachytes.     This  series  is  not  auriferous. 

Closing  the  volcanic  sequence  in  the  Peninsular  area,  and 
developed  only  on  the  east  and  south,  are  thick  deposits  of  rhyolite, 
both  glassy  and  pumiceous.  Outside  the  Peninsular  area  are  later 
eruptions  of  basalt  on  the  Auckland  Isthmus,  and  of  pyroxenic 
andesite  in  the  Hot  Lakes  region  to  the  south. 

Auriferous  deposition  is  practically  confined  to  the  older 
andesites,  and  to  those  only  where  propylitization  has  been  extensive. 
Propylitization  here,  as  elsewhere  in  auriferous  regions,  has  resulted 
in  the  conversion  of  the  felspars  and  ferro-magnesian  silicates  to 
chlorite,  quartz,  calcite,  serpentine,  sericite,  epidote,  and  pyrite. 

This  area  contains  the  famous  Waihi  mine,  at  the  present  time 
potentially  the  greatest  of  the  world's  gold  mines.  Unlike  the 
majority  of  veins  on  andesitic  fields,  the  values  of  the  lodes  of 
Waihi  are  regular,  owing  nothing  to  shoots  or  bonanzas.  The 
matrix  is  quartz,  which  is  occasionally  chalcedonic.  Calcite  occurs, 
but  is  subordinate  and  of  no  importance.  Lindgren&  records  the 
presence  of  valencianite  or  secondary  orthoclase.  The  associates  of 
the  gold  are  pyrite,  sphalerite,  galena,  and  argentite,  and  probably 
chalcopyrite.  Pyrite,  calcite,  and  a  serpentinous  mineral  are 
abundant  as  metasomatic  replacements  of  the  adjacent  country 
rock,  while  valencianite  may  occur  there  in  veinlets  with  quartz 
and  calcite.  Manganese  oxides  occur,  which  furnish,  on  analysis, 
nickel  and  cobalt.  The  Waihi  bullion  carries  a  small  percentage 
of  selenium  originally  contained  in  the  sulphide-ore. 

Hungary. — The  only  auriferous  andesitic  region  not  bordering 
on  the  Pacific   Ocean  is  that  of  Hungary.     Its  gold-deposits  all 

a  "  Rocks  of  Cape  Colville  Peninsula,"  Wellington,  1906,  p.  56. 
b  Eng.  Min.  Jour.,  Feb.  2,  1905. 
E 


66  AURIFEROUS    PROVINCES. 

arise  from  solfataric  action  consequent  on  the  extrusion  of  andesites 
and  trachytes  along  the  inner  side  of  the  great  Carpathian  uplift. 
Three  main  areas  may  be  distinguished  :  (a)  The  Schemnitz  area  ; 
(b)  the  Transylvanian  (Dacian)  area,  and  (c)  the  Nagybanya  area. 
Clearly  to  be  associated  with  these  is  the  auriferous  dacite  area 
of  north-eastern  Servia. 

The  Schemnitz  region  lies  about  80  miles  north  of  Buda-Pesth 
in  the  Erzgebirge  of  Lower  Hungary.  Its  basement  rocks  are 
Triassic  ;  these  are  overlain  by  Eocene  Nummulitic  shales. 
Volcanic  eruptions  commenced  about  the  middle  of  the  Mediter- 
ranean stage.  The  order  of  succession  appears  to  have  been 
pyroxene-andesite,  diorite  and  quartz-diorite,  aplite,  biotite-  and 
amphibole-andesite,  and  lastly  rhyolite,  which  is  the  predominant 
rock.  The  andesitic  varieties  are  now  propylitized.  Veins  are 
extremely  numerous,  and  some  are  continued  into  the  adjacent 
Miocene  strata.  The  Griiner  and  Spitaler  lodes  show  a  persistency 
in  length  exceptional  in  andesitic  areas.  The  latter  lode  has  been 
traced  for  7  •  2  miles.  The  gangue  and  associates  of  the  gold  are, 
with  the  exception  of  tellurides,  essentially  those  already  mentioned. 
The  Kremnitz  lodes  further  north  are  in  similar  rocks. 

The  oldest  rocks  of  the  Transylvanian  region  are  phyllites  and 
crystalline  schists.  These  are  hidden  by  Mesozoic  strata  which 
are  broken  through  and  covered  by  andesites,  dacites,  trachytes, 
and  rhyolites,  with  later  basalts.  The  andesites,  belonging  to  the 
Mediterranean  stage,  have  here  also  been  propylitized,  and  carry 
gold-quartz  veins  which  are  characterised  by  the  presence  of 
tellurides.  The  principal  fields  of  this  area  are  Nagyag,  Offenbanya, 
Faczebanya,  Fericsel,  Verespatak,  Vulkoj,  Botes,  Brad,  and  Boicza. 
The  mineral  veins  of  these  fields  show  the  "  stockwerk  "  features 
characteristic  of  most  andesitic  goldfields,  with  local  enrichments 
at  intersections.  On  the  Verespatak  field,  the  veins  occur  partly 
in  the  eruptive  rock  and  partly  in  the  adjacent  Carpathian  sand- 
stones. The  veins  in  the  latter  are  of  clean  quartz  with  free  gold, 
and  without  the  sulphides  and  tellurides  that  occur  with  the  gold 
in  the   propylites. 

The  Nagybanya  area,  which  includes,  among  others,  the  gold 
veins  of  Felsobanya  and  Kapnik,  lies  in  the  extreme  eastern  pro- 
vince of  Hungary  about  100  miles  north  of  the  foregoing  area.  It 
consists  of  propylitic  dacites,  rhyolites,  and  trachytes,  and  its  lodes 
present  the  same  characters  as  those  of  Schemnitz. 

A  general  consideration  of  the  characters  of  the  various  rocks 
that  go  to  make  up  a  normal  auriferous  andesitic  province  is  of 
interest  in  connection  with  the  question  of  the  origin  of  the  great 
auriferous  Archaean  schist  areas.    It  is  suggested  that  the  metamor- 


ORIGIN    OF   ANDESITIC    GOLD.  67 

phism  of  such  an  andesitic  assemblage  yields  a  complex  made  up 
mainly  of  amphibolitic  and  chloritic  schists,  and,  further,  that 
the  gold  contained  in  sulphides  and  as  tellurides  in  the  small  veins 
and  impregnated  areas  of  the  andesitic  rocks  is,  during  the  metamor- 
phism  of  the  enclosing  rock,  dissolved  and  re-deposited  generally 
with  quartz  in  the  major  thrust-plane  fissures  developed  by  folding. 
Petrological  examination  of  hornblende-schists,  such  as  those  of 
the  Kolar  field,  certainly  indicates  a  derivation  from  intermediate 
igneous  andesitic  rocks  that,  from  their  association  with  boulder- 
beds  and  grits,  were  obviously  deposited  at  the  earth's  surface. 
The  foregoing  assumption,  taken  in  conjunction  with  the  suggestion 
already  outlined,  viz.,  that  the  gold  of  an  andesitic  area  is  derived 
from  older  underlying  or  adjacent  auriferous  rocks,  indicates  a 
complete  cycle  in  the  history  of  gold,  from  depth  to  surface,  and 
from  surface  to  depth.  In  the  present  state  of  our  knowledge  the 
relations  outlined  are  to  be  regarded  as  highly  speculative. 


GOLDFIELDS  ASSOCIATED  WITH  ROCKS  THAT  ARE  IN 
THE  MAIN  OF  GRANODIORITIC  TO  GRANITIC  TYPES. 


The  characters  of  the  auriferous  provinces  already  outlined 
are  well  marked,  and  the  grouping  there  adopted  has  been  fairly 
obvious.  The  affinities  of  the  two  principal  members  of  this,  the 
third  great  group,  are  not  less  evident.  In  each  case,  viz.,  in  the 
Californian  and  Southern  Alaskan  regions  of  Western  North 
America  hi  the  first  instance,  and  along  the  mountain  axis  of 
Eastern  Australia  in  the  second  instance,  auriferous  deposition  is 
clearly  genetically  connected  with  a  single,  often  protracted  period 
of  igneous  activity.  The  age  of  the  first  is  probably  to  be  referred 
to  the  Jurassic,  that  of  the  second  to  the  Permo-Carboniferous  period. 
Considering  the  general  retardation  in  geological  time  of  the  Aus- 
tralian continent  the  intrusion  or  extrusion  of  these  magmas  may 
be  much  nearer  in  point  of  actual  time  than  their  respective  geo- 
logical horizons  would  indicate.  The  relations  of  the  third  member 
of  this  group,  covering  as  it  does  the  scattered  goldfields  lying  along 
the  eastern  slopes  of  the  Ural  Mountains  in  Russia,  are  by  no  means 
so  evident  as  the  foregoing  ;  but  it,  nevertheless,  seems  to  fall 
naturally  into  this  section.  The  general  meridional  distribution 
of  all  three  provinces  of  the  group  is  merely  an  expression  of  the 
general  direction  of  the  lines  of  the  earth's  crustal  weakness  along 
which  mountain  chains  are  formed  ;  it  has  probably  no  bearing 
on  the  present  subject.     All  three  provinces  show  a  characteristic 


68  AURIFEROUS  PROVINCES. 

mingling  of  igneous  rocks  of  various  types.  While  in  every  case 
the  general  facies  of  the  magma  has  been  granodioritic  to  granitic 
there  are,  nevertheless,  older  or  younger  rocks  of  intermediate  or 
even  basic  types.  It  is  here  that  the  weakness  of  the  classification 
now  adopted  for  these  three  provinces  lies  ;  for  it  is  not  possible 
to  determine  in  the  present  state  of  our  knoAvledge,  whether  auri- 
ferous impregnation  is  to  be  referred  to  the  main  granodioritic 
magma  or  to  the  possibly  genetically-connected  intermediate 
magmas  that  preceded  or  followed.  Should  it  hereafter  be  demon- 
strated that  the  auriferous  content  of  these  groups  is  dependent  on 
intermediate  (dioritic)  or  slightly  basic  intrusions,  a  great  advance 
will  have  been  made,  since  these  provinces  will  then  fall  into  line 
with  the  goldfields  of  Archaean,  Pre-Cambrian,  and  Tertiary  times. 
In  the  Tertiary  igneous  auriferous  provinces  an  entirely  similar 
differentiation  of  magmas  has  obtained,  andesites  and  dacites  being 
often  succeeded  by  rhyolites  and  basalts,  a  succession  which  may 
be  considered  to  be  entirely  analogous  to  the  relations  of  the  grano- 
diorite,  granite,  and  diabase  now  exposed  by  denudation. 

In  an  important  economic  respect,  the  three  provinces  of  the 
group  agree  closely  ;  they  have  furnished  the  great  placer-gold 
deposits  of  the  world.  To  this  feature,  however,  two  factors,  one 
inherent  and  the  other  external,  have  mainly  contributed.  In 
the  first  place,  the  gold  of  the  veins  of  this  group  is  generally  free 
and  coarse,  and  has  been  enclosed  within  a  quartz  matrix  from  which 
it  has  been  dissociated  with  ease  ;  secondly,  these  areas  have, 
during  Tertiary  times,  been,  in  general,  areas  of  elevation.  The 
erosion  and  degradation  of  the  upper  portion  of  their  gold-quartz. 
veins,  with  a  consequent  separation  and  sorting  of  their  heavy 
minerals  has  thus  been  rendered  possible.  It  is  further  characteristic 
of  the  gold-quartz  veins  of  this  group  that  they  show  no  very 
decided  dependence  for  country  on  the  igneous  members  of  the 
various  complexes  in  which  they  are  found,  but  occur  indifferently 
in  igneous  rock  or  in  adjacent  sedimentary  or  metamorphic  rock, 
favouring,  perhaps,  carbonaceous  shales  or  slates. 

Western  North  America. — The  auriferous  granodioritic 
region  of  Western  North  America  has  been  closely  studied.  From 
the  State  in  which  it  shows  the  greatest  development,  it  has 
generally  been  termed  the  Calif ornian  belt.  It  may  be  traced 
northwards  from  the  Lower  California  peninsula  in  Mexico  to  the 
flanks  of  the  great  Sierra  Nevada  chain,  through  the  western  foot- 
hills of  which  it  runs  the  length  of  California.  In  Oregon  it  carries 
goldfields  of  minor  importance.  With  the  main  Calif  ornian  belt  are 
probably  to  be  grouped  the  rocks  of  the  gold-quartz  veins  of  the 
Blue  Mountains  in  north-east  Oregon  ;     those  north  of  the  Snake- 


CALIFORNIA.  69 

river,  in  Idaho  ;  and  many  of  the  auriferous  vein  occurrences  of 
Montana.  The  sulphide  deposits  of  Rossland  across  the  inter- 
national boundary  in  Canada  are  possibly  also  to  be  grouped  here. 
Whatever  may  be  the  relations  of  these  last,  there  is,  however, 
no  doubt  of  the  close  connection  of  the  auriferous  occurrences  of 
the  Southern  Alaskan  seaboard  with  those  of  California  ;  they 
are  certainly  to  be  considered  as  forming  a  northward  continuation 
of  the  Calif ornian  belt. 

Lindgrena  has  clearly  shown  that  the  gold-quartz  veins  of  the 
Calif  ornian  belt  are  always  closely  associated  with  the  '  meta- 
morphic  series,"  comprising,  in  this  case,  a  great  assemblage  of 
rocks  ranging  in  age  from  Early  Palaeozoic  to  Jurassic,  and  con- 
taining among  its  sedimentary  members  altered  slates,  sand- 
stones, and  limestones,  together  with  more  or  less  metamorphosed 
quartz-porphyrite,^  augite-  or  hornblende-porphyrite,  diabase,  and 
amphibolite  as  representatives  of  probably  intercalated  igneous 
rocks.  Gabbros  and  serpentines  also  occur,  but  are  not  abundant. 
Through  all  of  these,  and  also  through  the  later  granite  and 
granodiorite  (quartz-mica-diorite  with  a  little  orthoclase),  there 
run  auriferous  quartz  veins,  which  certainly  seem  to  be  more  closely 
connected  with  the  granodiorite  than  with  any  other  intrusive  rock. 

The  granodiorite  is  a  rock  intermediate  between  a  granite  and 
a  quartz-diorite.  With  it,  and  often  inseparable  from  it,  are 
various  types  of  gabbro-diorite.  The  "  porphyrite  '  group  is 
commonly  termed  the  "  greenstone  series,"  and  comprises 
various  diabases  and  porphyrites  that  are  now  often  largely  urali- 
tized.  The  relations  of  these  rocks  to  the  granodiorite  are  far 
from  clear,  and  different  successions  have  been  advanced  as  a  result 
of  work  in  different  regions.  The  most  widely-accepted  sequence 
of  events  in  the  Mesozoic  eruptions  commences  with  intrusions  of 
gabbro-diorite  and  granodiorite,  is  continued  by  the  extrusion  of 
diabase  and  porphyrite,  and  is  completed  by  further  intrusions  of 
granodiorite.  As  a  result  of  contact  metamorphism,  the  Mariposa 
slates,  though  only  of  Late  Jurassic  age,  are,  near  contacts,  altered 
into  mica-schist  and  andalusite-schist.c 

The  most  striking  member  of  the  California!!  auriferous  veins 
is  the  "  Great  Mother  Lode,"  which  is  essentially  a  longitudinal 
series  of  quartz  veins  developed  along  a  strike  fault  area  for  more 
than  a  hundred  miles.  Quartz  is  the  dominant  matrix,  but  calcite, 
dolomite,  and  ankerite  also  occur.  The  associates  of  the  gold  in 
the    veins    are    various    sulphides  :     pyrite,    arsenopyrite,    galena, 

a  Bull.  Geol.  Soc.  Am.,  VI,  1895,  p.  225. 

"  Pre-Tertiary  andesite. 

£Forstner,  Min.  Sci.  Press,  1908,  p.  744. 


70  AURIFEROUS   PROVINCES. 

chalcopyrite,  tetrahedrite,  and  blende.  Tellurides  also  occur.  Gold 
has  been  noted  as  occurring  in  albite  veinlets  ramifying  through  a 
porphyrite. 

To  be  associated  with  the  Californian  occurrences  are  the 
Southern  Alaskan  coastal  mines.  Of  these,  the  Douglas  Island 
deposits  have  been  the  most  closely  investigated.  The  country 
rock  in  the  vicinity  of  the  Alaska-Treadwell  ore-deposit  is,  as  in 
Victoria  and  often  in  California,  a  carbonaceous  slate.  The  slate 
has  been  intruded  by  an  albite-diorite  dyke,  consisting  essentially 
of  albite,  with  a  little  augite,  hornblende,  biotite,  and  a  small 
quantity  of  a  plagioclase  felspar  more  basic  than  albite.  Further 
crushing  and  metamorphism  was  followed  by  the  intrusion  of  a 
diabase  or  gabbro  (augite  and  plagioclase).  The  gabbro  appears 
to  have  had  no  effect  on  the  mineralisation,  but  a  still  later  analcite- 
basalt  dyke  seems  to  have  set  mineralising  solutions  in  circulation 
and  to  have  filled  two  series  of  fissures  in  the  albite-diorite.  These 
series  lie  at  right  angles  to  each  other  at  about  45°  to  the  horizon. 
The  vein-filling  is  quartz  and  calcite,  and  the  associates  of  the  gold 
are  auriferous  pyrites,  chalcopyrite,  mispickel,  blende,  and  galena. 

Eastern  Australia. — The  great  chain  of  important  goldfields 
developed  along  the  Eastern  Cordilleras  of  Australia — to  use  the 
term  proposed  many  years  ago  by  Murchison  for  this  mountain 
range — are  apparently  all  to  be  assigned  to  strongly-developed 
igneous  intrusions  of  a  general  granodioritic  facies.  Recent 
geological  work  has  thrown  considerable  light  on  the  age  of 
these  intrusions.  They  are  certainly  older  than  Triassic 
times,  and  would  appear  to  have  reached  their  maximum 
development  in  the  Carboniferous  period  ;  at  least,  so  far  as 
the  main  granodioritic  intrusion  is  concerned.  There  is  evidence  of 
earlier  igneous  activity,  indicated  by  the  possibly  Lower  Devonian 
porphyrites  of  the  Snowy  River  and  Mitta  Mitta  Valley,  East 
Gippsland,  and  there  has  been,  subsequent  to  the  deposition 
of  the  Permo-Carboniferous  sedimentary  beds,  a  widespread  in- 
trusion of  more  basic  (dioritic)  members.  These  last  are  exceedingly 
important  from  our  present  standpoint,  and  are  certainly  responsible 
for  auriferous  deposition  on  several  fields  (Mount  Morgan,  Gympie, 
Lucknow,  Woods  Point,  Walhalla,  &c).  The  diorite  dykes  are 
perhaps  most  naturally  to  be  considered  as  later  magmatic  segrega- 
tions from  the  main,  more  acid  magma.  There  is  thus  in  this  area 
a  considerable  similarity  to  the  Californian  province  already  outlined. 
The  granodioritic  and  granitic  intrusion  is  clearly  a  result  of  the 
action  of  the  orogenic  forces  that  have,  in  the  course  of  geological 
ages,  built  up  the  mountain  ranges  of  the  eastern  seaboard.  The 
rocks  and  veins  of  Tasmania  must  be  grouped  with  those  of  the 


EASTERN   AUSTRALIA.  71 

mainland,  since  that  island  has  only  very  recently  been  separated 
from  Australia. 

In  southern  New  South  Wales,  Victoria,  and  Tasmania  the 
acid  igneous  rocks  show  a  relatively  small  exposure  at  the  surface 
in  auriferous  areas,  but  further  north,  in  Queensland,  either  from 
a  greater  development  nearer  the  surface  or  from  greater  erosion, 
they  bulk  largely  in  the  auriferous  complex.  Speaking  generally, 
therefore,  goldfields  occur  in  the  north  (Croydon,  Ravenswood, 
Charters  Towers,  &c.)  in  the  igneous  rocks  ;  while  in  the 
south,  as  in  Victoria  and  Tasmania,  they  occur  in  the  overlying  or 
adjacent  sedimentary  rocks.  To  this  general  rule  there  are  notable 
exceptions.  In  Queensland  both  the  famous  Mount  Morgan  mine 
and  the  Gympie  field  are  in  the  sedimentary  rocks  of  the  Gympie 
(Lower  Carboniferous)  series.  Another  division  of  the  goldfields 
of  the  belt,  and  one  dependent  on  the  character  of  the  ore-matrix, 
may  also  be  made,  inasmuch  as  some  carry  highly  refractory 
auriferous  sulphide-ores,  while  others  yield  only  clean  quartz  with 
free  gold.  It  will,  on  examination,  be  found  that  the  former  are 
restricted  to  the  typical  acid  igneous  rocks,  while  the  latter  He 
within  sedimentary,  and  often  carbonaceous  beds.  Further,  it  may 
be  seen,  as  at  the  Etheridge  and  Ravenswood,  in  Queensland,  that 
where  auriferous  veins  pass  from  granite  or  granodiorite  into  ad- 
jacent sedimentary  rocks,  the  dense  sulphide-ore  of  the  former 
tends  to  give  place  in  the  latter  to  quartz  with  free  gold.  The 
veins  of  the  Croydon  goldfield  in  aplitic  granite  carry  quartz  with 
free  gold  and  little  pyrite  ;  this  is,  however,  not  a  real  exception  to 
the  general  rule,  since  both  the  country  and  the  fissures  contain 
large  quantities  of  graphite.  There  is,  therefore,  reason  to  believe 
that  no  genetic  distinction  between  the  filling  of  the  veins  of  the 
respective  fields  may  be  made,  and  that  the  difference  arises  from 
the  segregative  influence  of  the  carbonaceous  matter  of  sedimentary 
beds  on  pyrite  and  gold.  In  these  beds  the  pyrite  affects  the  country, 
leaving  quartz  and  gold  to  be  deposited  in  fissures. 

The  granite  of  the  northern  fields,  as  of  Croydon,  is  of  a 
curiously  aplitic  type  ;  it  is  further  characterised  by  the  presence 
of  considerable  quantities  of  a  graphite  that  possibly  represents 
portions  of  Permo-Carboniferous  coalfields  caught  up  by  intrusive 
magmas.  Normal  granite  occurs,  but  is  not  common  on  the 
northern  goldfields.  Rocks  of  the  granodioritic  type  may  often  be 
described,  as  from  Charters  Towers,  with  greater  particularity  as 
tonalite  or  quart z-mica-diorite. 

In  the  southern  regions  the  sedimentary  beds  of  Ordovician  and 
Silurian  age  form  the  normal  locus  of  the  auriferous  veins,  which 
have  often  been  formed   along   the  corrugations  into  which  these 


72  AURIFEROUS   PROVINCES. 

beds  have  been  folded,  in  this  case  giving  rise  to  the  "  saddle 
reefs,"  peculiarly  distinctive  of  Bendigo. 

Of  the  goldfields  in  acid  igneous  rocks,  Charters  Towers  is 
probably  typical.  Its  veins,  as  already  stated,  lie  in  a  complex  of 
granitic  and  granodioritic  rocks,  through  which,  as  may  be  seen 
from  an  inspection  of  the  geological  map  attached  (Fig.  103),  there 
ramify  numerous  felsitic  and  dioritic  and  even  more  basic  intrusions. 
It  is  probable  that  the  serpentine  area,  as  shown  in  the  map, 
represents  merely  a  weathered  diorite  or  diabase.  Close  to 
the  igneous  rocks  and  intruded  by  them  are  slates  and  schists  of 
probable  Middle  Devonian  age.  The  main  reefs  of  Charters  Towers 
are  the  Brilliant  and  the  Day  Dawn.  These  are  in  depth  highly 
pyritous. 

The  characters  of  two  only  of  the  numerous  goldfields  developed 
in  sedimentary  rocks  may  here  be  indicated. 

Ballarat. — The  rocks  of  this  field  are  nearly  vertical  Ordo- 
vician  slates  and  quartzites,  and  are  intruded  by  granitic  dykes 
which  appear  to  be  connected  with  the  origin  of  the  gold,  and  which 
are  considered  to  be  of  later  Palaeozoic  age.  The  period  of  auriferous 
deposition  thus  seems  to  be  fairly  well  marked.  The  goldfield  itself 
lies  some  little  distance  to  the  west  of  intrusive  granitic  rocks  (quartz- 
monzonites  of  Lindgren).  Tertiary  basic  dykes  (limburgites)  are  also 
intrusive  through  the  Silurian  slates,  but  have  no  cbnnection  with 
auriferous  deposition,  and,  indeed,  are  the  intrusive  representatives 
of  the  great  Tertiary  basaltic  flows  of  Victoria. 

The  most  notable  features  on  the  Ballarat  East  field  are  the 
"  indicators  " — narrow  black  pyritous  bands  striking  with  the 
country  and  bedded  parallel  or  nearly  so  with  it.  They  have  generally 
been  regarded  as  original,  highly  carbonaceous,  pyritous  bands 
interbedded  with  the  country,  but  Gregory0  has  lately  shown  that 
they  are  not,  as  a  rule,  composed  of  pyrite  and  arsenopyrite,  but 
rather  of  ferruginous  chlorite.  One,  the  "  Pencil  Mark,"  owes  its 
dark  colour  to  rutile.  Prom  the  nature  of  the  filling,  and  from  his 
observation  that  the  indicators  do  break  across  the  bedding,  Prof. 
Gregory  maintains  that  they  are  filled  fissures.  This  view  is  not 
generally  accepted  by  local  geologists. 

The  quartz  veins  of  Ballarat  are,  on  the  whole,  thin  and 
irregular,  and  have  been  worked  almost  entirely  in  connection  with 
the  indicators,  since  these  last  have  considerable  continuity,  and, 
where  they  cut  the  "  flat  makes  "  (horizontal  floors)  of  quartz,  are 
the  cause  of  much  local  enrichment.  Of  late  years,  a  considerable 
amount  of  profitable  mining  has  been  carried  on  in  quartz  veins 
developed  along  strike  faults. 

aMin.  Jour.,  June  20,  1900. 


BALLABAT. 


73 


The  painstaking  research  work  of  Dona  shows  clearly  that  the 
country  rock  of  Ballarat  away  from  a  vein  is  barren,  and  that  it  is 
only  where  pyrites,  obviously  introduced  from  the  vein,  occurs  that 
the  country  rock  carries  any  values  in  gold.  He  also  points  out 
the  auriferous  character  of  the  pyrites  of  an  acid  eruptive  (felsite- 
porphyry)  dyke  analysed  by  him,  the  highest  analysis  (with  also 
the  greatest  amount  of  pyrites)  yielding  as  much  as  6  •  7  grains  per 
ton.  A  genetic  association  of  auriferous  lode  and  acid  dyke  is 
suggested. b 


i'r'i'T 


EH  EEJj        ^       | 


iimmmk 


m 


Sandstones. 


Shales. 


Quartz 
Vein. 


Indicator. 


Sin  lot 
ol  Gold. 


Fig.  66.     Showing  Shoot  of  Gold  at  Intersection  of  Quartz  Vein  and  Indicator 

(Richard). 

Bendigo. — The  veins  of  Bendigo  are  contained  in  Ordovician 
black  clay -slates  that  have  been  compressed  into  a  series  of  anti- 
clines and  synclines.  The  auriferous  quartz  occurs  at  the  crest  of  a 
number  of  parallel  anticlinals  forming  the  well-known  "  saddle 
reefs,"  i.e.,  veins  with  their  greatest  thickness  at  the  crest  of  the 
anticlinal  and  with  a  dip  away  on  either  side,  forming  the  "  legs," 
which  gradually  thin  out  in  depth  and  disappear.  Beside  the  dip 
of  the  "  legs,"  the  quartz  bodies  have  also  the  pitch  of  the  anti- 
clinal axis.     Quartz  is  also  formed  along  the  corresponding  syn- 

«  Trans.,  Amer.  Inst.  M.E.,  XXVII,  1897,  p.  568. 
°  Loc.  cit.,  p.  573. 


74  AURIFEROUS    PROVINCES. 

clinal  axes,  but  is  not  there  notably  auriferous.  The  folding  of  the 
clay -slates  and  sandstones  is  occasionally  very  sharp.  The  three 
principal  anticlinals  of  Bendigo,  the  New  Chum,  Garden  Gully,  and 
the  Hustler,  are  contained  within  a  distance  of  150  yards.  Several 
;'  saddle  reefs  "  msiy  occur  on  the  one  anticlinal,  one  being  super- 
posed on  the  other  at  varying  intervals  in  the  sedimentary  beds. 
Besides  the  quartz  of  the  saddle  reefs,  there  are  also  found  irregular 
branches  of  auriferous  quartz,  in  more  or  less  obvious  connection, 
however,  with  the  characteristic  form  of  quartz  vein. 

The  quartz  of  the  veins  seems  to  be  a  simple  vein-filling,  growing 
probably  with  the  folding  of  the  sedimentary  rocks.  The  gold  is 
free,  and  is  easily  seen  in  the  clear  glassy  quartz.  Sufficient 
chlorite  to  give  a  greenish  colour  occasionally  occurs  embedded 
in  the  quartz.  As  at  Ballarat,  the  usual  sulphides  are  pyrite  and 
arsenopyrite,  with  a  little  galena.  Subsequent  vein-filling  has  given 
carbonates  of  iron,  lime,  and  magnesia.  Albite  occurs  intergrown 
with  quartz  in  drusy  cavities." 

No  direct  connection  with  granitic  intrusions  has  been  noted 
on  this  field,  but  a  granitic  batholith  (quartz-monzonite  of  Lindgren) 
occurs  a  little  to  the  south  of  the  auriferous  area. 

Ural  Mountains. — The  relations  of  the  group  of  gold-quartz 
veins  scattered  along  the  eastern  flanks  of  the  Ural  Mountains  are 
not  well  defined,  nor  may  either  their  geological  age  or  that  of  their 
enclosing,  generally  granitic  country  be  stated  with  any  approach 
to  accuracy.  They  may,  however,  be  of  Late  Palaeozoic  age. 
The  area  presents  so  many  features  in  common  with  those  of  the 
two  preceding  provinces,  that  it  must,  for  the  present  at  least,  be 
grouped  with  them.  There  are  the  same  indications  of  a  wide- 
spread acid-magma,  in  this  case,  however,  rather  granitic  than 
granodioritic,  with  which  have  been  associated,  as  also  in  the  two 
already-described  provinces,  numerous  intrusions  of  more  basic 
rocks.  The  igneous  rocks  therefore  include  granite,  syenite,  quartz - 
porphyry,  felsite,  porphyrites,  diorite,  diabase,  gabbro,  norite,  and 
pyroxenite.  In  the  north,  and  especially  in  the  neighbourhood  of 
Berezovsk,  but  also  at  Tcheliabinsk  and  Kotchkar,  the  gold-quartz 
veins  form  a  network  of  stringers  in  microgranitic  rocks  that  are 
either  intrusive  or  massive.  The  typical  microgranitic  rock  of 
Berezovsk  has  been  termed  "  beresite."  Gold-quartz  veins  also  occur 
in  the  older  schists  and  in  diabasic  and  serpentinous  rocks,  the 
latter  association  being,  perhaps,  best  marked  toward  the  south 
of  the  auriferous  region.  While  the  country  of  the  northern  veins 
is  generally  acid,  auriferous  deposition  is  attributed  by  Purington6 

"Lindgren,  Econ.  Geol.,  I,  1905,  p.  163. 
b  Eng.  Min.  Jour.,  June  13,  1903,  p.  894. 


URALS.  75 

to  the  influence  of  intrusive  basic  rocks.  Purington,  indeed,  con- 
siders the  deposits  of  Berezovsk  to  be  entirely  analogous  to  those 
of  the  Alaska-Treadwell  on  Douglas  Island,  and,  further,  that  the 
distribution  of  the  gold-deposits  is  largely  governed  by  that  of 
the  basic  rocks. 

The  gold-bearing  veins  of  Tcheliabinsk,  according  to  Kar- 
pinsky,a  lie  in  a  country  of  highly  dynamo-metamorphosed  granite, 
in  part  a  hornblende-granite.  The  vein-filling  consists  of  com- 
pletely decomposed  country  and  of  quartz,  the  latter  occurring 
often  as  a  stock  work. 

The  Berezovsk  rocks  are  highly  metamorphosed  muscovite- 
granite  schists  and  mica-schists  traversed  by  numerous  dykes 
of  microgranite  and  of  basic  rocks.  The  acid  intrusive  rock,  and 
not  the  schist,  is  the  country  of  the  gold,  since  across  the  micro- 
granites  from  wall  to  wall  there  extend  numerous  thin  auriferous 
quartz  veinlets.  The  associates  of  the  gold  are  mainly  sulphides, 
pyrite,  chalcopyrite,  aikinite  (Pb  Cu  Bi  S3),  chalcocite,  and  com- 
pact galena.  Very  frequently  also  the  quartz  contains  long  needles 
of  a  grey-green  tourmaline,  running  at  right  angles  to  the  walls. 
There  also  occur  pseudomorphs  of  tourmaline  after  pyrites.  It  is 
suggested  that  the  microgranite  (aplite)  dykes,  which,  by  the  way, 
recall  very  strongly  the  massive  aplitic  rock  of  Croydon,  Queens- 
land, may  be  genetically  connected  with  the  neighbouring  granite 
massif  of  Lake  Shartash. 

The  Kotchkar  veins  in  Orenburg6  are  also  in  sheared  and 
decomposed  granite.  The  gold  is  associated  with  auriferous  arseno- 
pyrite,  which  also  impregnates  the  adjoining  granite  to  a  con- 
siderable extent. 

Other  Fields. — Further  geological  research  may  bring  into 
the  granitic  or  granodioritic  group  two  widely-separated  areas  in 
which  the  relations  of  auriferous  vein-filling  are  very  obscure, 
viz.,  those  of  the  Alps,  in  France,  Piedmont,  and  the  Tyrol,  and 
those  of  the  South  Island  of  New  Zealand,  in  Otago  and  West  land. 
Both  are  apparently  to  be  attributed  to  Middle  and  Late  Mesozoic 
mountain  building,  during  which  acid  magmas  were  intruded  into 
the  rock  complex.  Tonalites  (quartz-mica-diorites)  are  especially 
well  developed  along  the  Alpine  fold  ;  they  are  generally  disposed 
along  a  line  to  the  south  of  that  of  the  auriferous  occurrences  ; 
but  here  also  the  question  is  complicated  by  the  intrusion  of 
augite-porphyry  and  more  basic  rock,  also  of  undetermined,  and 
possibly  of  indeterminate  age. 


a  Guide  des  excursions  du  VII  Congres.     Geolog.  Internal?.,  1S97,  p.  30. 
b  Trans.  Am.  Inst.  M.E.,  XXXIII,  1899,  p.  24. 


76 


GENERAL    CONSIDERATIONS. 


From  the  foregoing  facts,   of  necessity  briefly  detailed    and 
outlined,  we  may  reasonably  make  certain  deductions.     The  almost 
invariable  direct  association  of  auriferous  veins  with  igneous  rocks, 
even  when  taken  with  the  few  cases  that  are  not  obviously  so 
associated,  indicates  with  some  certainty  that  auriferous  veins  are 
formed  by  waters  derived  from,  or,  more  often,  set  in  circulation  by 
the  heat  of  igneous  magmas  and  intrusions.     That  heat  alone  is 
insufficient  to  produce  auriferous  veins  is  clearly  shown  by  the  fact 
that  they  do  not  accompany  every  variety  of  igneous  rock.     Basalts, 
trachytes,  and  rhyolites  are  notoriously  non-auriferous,  and,  indeed, 
the  only  volcanic  rock  strikingly  gold-bearing  is  the  andesitic  type. 
Among  plutonic  rocks  connected  with  gold-veins,  there  is  a  much 
greater  range — granites,  tonalites,  diorites,  and  diabases  furnishing 
goldfields.     The  diabases  must,  however,  be  regarded  merely  as 
vehicles  of  heat,  since  they  are,  as  has  been  shown,  operative  only 
in  pre-existing  auriferous  rocks,  as  in  the  Archaean  schists.       The 
diorites,   again,   are  merely  the  plutonic  forms  of  the  auriferous 
andesites.    There  are  thus  left  the  tonalites  and  the  granites.    Some 
of  these  resemble  the  diabases  in  being  merely  heat  carriers  ;    but 
others,  as  those  of  North  Queensland,  cannot  so  simply  be  explained. 
The  salient  fact,  therefore,  remains  that  the  prominent  goldfields  of 
the  world  are  associated  with  intermediate  igneous  rocks  and  with 
granites  and  tonalites.       The  granites  and  the  tonalites  may  be 
for  the  moment  neglected,  since  the  data  regarding  them  are  too 
scanty  to  permit  of  deduction  with  the  slightest  approach  to  safety, 
and  since  the  auriferous  deposition  exhibited  in  them  may  well  be 
due  to  the  basic  rocks  by  which  they  are  always  intruded.     There 
remain,    therefore,    closely   connected   with   auriferous   deposition, 
the  Archaean  schists  and  the  andesites,   and  these,   indeed,   con- 
stitute the  bulk  of  the  world's  auriferous  rocks.     The  auriferous 
Archaean  schists  show,  in  the  main,  that  they  are  of  igneous  origin, 
and  they  may  often  fairly  safely  be  considered  to  represent  ancient 
intermediate  rocks — probably  andesites.      A  clear  distinction  must 
here  be  made  between  the  younger  and  older  veins  of  the  Archaean 
schists.      The  older  veins  have  shared  in  the  metamorphism  of  the 
schists,  and  no  evidence  of  their  origin  remains,  but  it  may  well 
be  considered  to  be  due  to  solfataric  action  similar  to  that  which 
has  formed  most  of  the  Tertiary  andesite  veins.     In  short,  we  may 


ARCHiEAN    AND    TERTIARY   PROVINCES.  77 

have  in  the  auriferous  Archaean  schists  a  prototype  of  the  wide-spread 
auriferous  Tertiary  andesites.  In  another  place  the  writer  has 
endeavoured  to  establish  an  Archaean  auriferous  province  (the 
"  Erythraean  ")  for  the  countries  bordering  on  the  Indian  Ocean. 
This  province  is  considered  entirely  analogous,  for  example,  with 
the  Cordilleran  andesitic  province  of  North  America  and  Mexico  ; 
it  forms  part  of  an  Archaean  world-wide  auriferous  deposit,  of 
which  few  exposures  exist,  but  which,  nevertheless,  lies  under 
many  an  auriferous  region  of  younger  age.  It  may,  indeed,  be 
possible  in  the  future  to  establish  a  direct  connection  between 
the  Archaean  auriferous  schists  and  some,  at  least,  of  the  Tertiary 
andesitic  goldfields,  the  gold  of  the  latter  having  been  derived 
by  wandering  solutions  from  the  hidden  veins  of  the  former.  Out- 
side the  Erythraean  province,  the  old  schists  are  best  developed 
(as  the  Appalachian  Province),  in  eastern  North  America.  The 
recrudescence  of  auriferous  activity  in  these  schists,  wherever 
penetrated  by  dioritic  or  diabasic  dykes,  is  by  no  means  one  of 
the  least  striking  features  in  the  history  of  gold  deposition. 

The  question  now  naturally  arises  :  What  is  the  relation  between 
gold  and  the  andesitic  rocks  ?  Some  connection  certainly  does 
exist.  It  may  be  urged  against  the  views  set  forth  in  this  place  that 
no  actual  proof  has  been  adduced  that  the  association  is  more  than 
fortuitous,  and,  further,  that  the  gold  may  have  been  brought  into 
the  andesites  from  unknown  sources  at  miknown  depths.  But 
goldfields  do  not  occur  in  the  sedimentary  rocks  or  even  in  the 
rhyolites  or  basalts  that  often  surround,  or  occur  with,  the  andesites, 
and,  therefore,  though  it  is  merely  an  assumption  that  gold  depo- 
sition is  an  andesitic  function,  it  is  not  an  unwarrantable  assump- 
tion. Nevertheless,  no  direct  answer  to  the  above  question  may 
be  given  ;  the  solution  of  the  problem  awaits  further  chemical 
research,  probably,  like  other  problems  of  ore-deposition,  in  the 
direction  of  the  genesis  of  pyrite  and  other  sulphides. 

The  poverty  of  basaltic  regions  has  been  explained  a  on  the 
assumption  that  then  occluded  gases  pass  off  as  vapour,  and  are 
thus  not  available  in  vein  formation.  Indeed,  it  is  stated  that  all 
surface  flows  are  barren  for  this  reason.  But  as  will  be  abundantly 
shown  when  further  considering  the  Tertiary  andesites,  these 
latter  rocks  are  highly  metalliferous,  and  yet  they  are  not  less 
superficial  than  basalts,  trachytes,  or  rhyolites,  all  of  which  are 
devoid  of  auriferous  deposits. 

No  less  striking  than  the  restriction  of  gold-veins  to  certain 
rocks  is  their  discontinuity  in  geological  time  when  broadly  con- 
sidered.    There  is  the  gap  of  all  the  geological  table  between  the 

a  Kemp,  Trans.  Am.  Inst.  M.E.,  XXXI,  1902,  p.  169,  p.  G95. 


78  AURIFEROUS   PROVINCES. 

Archaean  schists  and  the  Tertiary  andesites — a  gap  but  imperfectly 
bridged  by  the  Permo-Carboniferous  gold-veins  of  Eastern  Australia 
and  by  the  Middle  Mesozoic  lodes  of  California.  With  one  exception, 
these  intermediate  deposits  appear  to  have  arisen  from  what  may, 
perhaps,  reasonably  be  termed  in  the  present  study  an  abnormal 
influence,  viz.,  that  of  acidic  magmas  which  may  further,  as  has 
been  suggested,  have  yielded  auriferous  solutions  only  with  their 
less  acid  segregations. 


SECONDARY  AURIFEROUS  DEPOSITS. 


Due  to  Chemical  Action  at  Depth. — Secondary  auriferous 
deposits  are  those  which  may  presumably  be,  or  obviously  are,  due 
to  the  influence  of  chemical  or  mechanical  agents  acting  on  older  or 
primary  gold  ores  or  gold  solutions.  Secondary  deposits,  beingthe  result 
of  subsequent  action,  are,  therefore,  generally  to  be  found  within 
the  limits  of  the  auriferous  provinces  already  outlined  and  very 
often  are  confined  to  the  same  fissure  or  ore-channel  that  holds  the 
primary  deposit.  From  our  knowledge  of  the  general  character 
of  gold-veins  in  depth,  it  may  perhaps  be  legitimately  assumed  that 
the  normal  primary  form  of  deposition  of  gold  is  an  auriferous 
sulphide  or  a  chemically-allied  gold-telluride,  and,  further,  that  the 
free  gold  of  quartz-veins  represents  the  products  of  decomposition 
of  auriferous  sulphides  and  tellurides.  The  propositions  are  self- 
evident  on  the  great  majority  of  goldfields,  but  there  are,  never- 
theless, numerous,  though  perhaps  only  apparent  exceptions.  The 
most  notable  examples  of  clean  quartz-veins  carrying  free  gold  to 
great  depths  are  those  of  Bendigo  and  Ballarat,  in  Victoria.  It 
has  been  shown  that  these  are  in  sedimentary  rocks  adjacent  to 
great  granodioritic  intrusions.  Two  alternative  explanations  have  been 
advanced  to  account  for  the  character  of  their  contained  gold. 
Either  the  free  gold  may  be  truly  secondary  and  may  be  due  to 
the  action  of  deep-seated  acid  waters  on  sulphide  or  telluride  ores, 
or,  and  more  probably,  the  auriferous  solutions  that  have  deposited 
quartz  and  free  gold  in  the  sedimentary  rocks  were  part  of  the  same 
aqueous  body  that  has  deposited  refractory  auriferous  sulphides 
in  adjacent  igneous  rocks,  the  difference  in  the  character  of  the 
deposit  being  due  to  the  known  segregative  action  of  the  car- 
bonaceous matter  of  the  sedimentary  rocks,  pyrite  being  deposited 
generally  in  the  country  adjacent  to  the  fissure,  leaving  quartz  and 
free  gold  to  form  veins  by  simple  fissure-filling.  In  the  second 
case,  therefore,  the  deposit  must  be  regarded  as  truly  primary, 
using  the  word  in  the  sense  already  defined.     Additional  evidence 


SECONDARY    DEPOSITION    AT    DEPTH.  79 

for  regarding  many  of  the  deep-seated  free-gold  deposits  of  Eastern 
Australia  as  primary  is  afforded  by  the  fact  that  where  no  natural 
precipitant  is  present  in  the  sedimentary  rocks,  the  auriferous 
deposit  even  in  those  may  be  sulphide-ore,  and,  further,  that  where 
carbonaceous  matter  is  present  in  the  igneous  rocks,  as  at  Croydon, 
free  gold  in  clean  quartz  may  result.  At  Mount  Morgan,  where  the 
Gympie  beds  are  sandstones  and  contain  no  carbonaceous  matter, 
uprising  solutions  have  deposited  their  metallic  contents  as  sul- 
phides, and,  under  the  influence  of  mass  action,  their  silica  as  a 
•cement    or    replacement. 

The  Champion  Reef  of  the  Kolar  goldfield,  in  India,  furnishes 
another  example  of  gold-quartz  deposited  at  great  depths.  The 
evidence  available  renders  it  impossible  to  say  whether  its  gold 
is  truly  secondary.  Should  its  schistose  country  be  admitted  as 
having  originally  formed  an  auriferous  andesitic  complex,  as  has 
already  been  suggested,  the  secondary  nature  of  the  gold  of  the  vein 
may  also  reasonably  be  assumed. 

While  free-gold  of  secondary  origin  is  certainly  not  common 
in  the  deep  zones  below  the  reach  of  oxidising  waters,  some  free-gold, 
such  as  that  found  at  Kalgoorlie  below  the  2,000  feet  level,  is  obviously 
derivative,  arising  from  the  action  of  deep-seated  acid  waters  on 
sulphides  or  tellurides,  or  of  tellurides  on  passing  gold  solutions. 
Deep-seated  waters  are  probably  generally  alkaline,  but  it  is 
obvious  from  a  consideration  of  fumarolic  vapours  and  solfataric 
waters  that  they  may  at  given  times  and  in  certain  places  be  de- 
cidedly acid.  Maclaurin"  on  analysis  found  the  hot  waters  (110°  F.) 
of  a  lake  15  acres  in  extent,  on  White  Island,  New  Zealand,  to 
contain  5  •  47  per  cent,  of  free  hydrochloric  acid,  or  more  than  one- 
sixth  of  that  contained  in  ordinary  commercial  hydrochloric  acid. 
In  this  connection  the  recent  work  of  Lane,&  showing  that  at  great 
depths  the  waters  of  the  Michigan  copper  area  are  essentially 
saturated  chloride  solutions,  is  of  importance. 

Exceedingly  important  secondary  auriferous  sulphide  deposits 
are  formed  immediately  below  the  zone  of  oxidation  by  descending 
solutions.  It  is  probable  that  secondary  deposits  of  gold-tellurides 
are  deposited  in  the  same  way.  It  will  be  sufficient  in  the  present 
place  to  indicate  the  existence  of  secondary  auriferous  sulphide  and 
gold-telluride  deposits  ;  their  characters  and  method  of  formation 
will  be  considered  at  length  under  the  heading  of  "  secondary 
enrichment." 

Due  to  Chemical  Action  near  the  Surface. — The  changes 
that  take  place  in  the  chemical  composition  of  gold-ores  as  they 

a  41st  Amu  Rep.  Dominion  Laboratory,  New  Zealand,  1908,  p.  30. 
h  Amer.  Geol.,  XXIV,  1904,  p.  302. 


80  SECONDARY    AURIFEROUS    DEPOSITS. 

are  gradually  subjected  to  the  influence  of  oxidising  waters,  in  the 
progress  of  the  denudation  of  the  overlying  rock,  are  of  the  utmost 
economic  importance.  Briefly,  the  essential  process  for  gold  is  one 
of  liberation  from  auriferous  sulphides.  An  immediate  reduction 
to  the  metallic  state  is  possible,  but  the  normal  result  is  either 
re-deposition  as  free  gold  in  the  zone  of  oxidation,  or  with  sulphides 
at  the  top  of  the  sulphide  zone.  For  the  associated  base  sulphides 
the  change  is  to  native  metal,  oxide,  chloride,  carbonate,  or  sul- 
phate, the  oxides  of  iron  being  as  a  rule  especially  abundant,  and 
forming  a  ferruginous-red  deposit  that  with  quartz  constitutes  the 
"  ironstone  "  of  the  Australian  and  the  "  gossan  "  of  the  Cornish 
miner.  The  depth  of  the  oxidised  zone,  of  course,  varies  considerably, 
and  depends  on  the  level  of  the  permanent  ground-water ;  it  is  usually, 
therefore,  from  50  to  250  feet  below  the  surface.  In  glaciated  and 
boreal  regions,  it  is  usually  shallow  ;  in  elevated  desert  regions, 
which  yet  receive  a  rainfall,  it  may  be  very  deep.  The  economic 
aspect  of  the  changes  that  take  place  in  this  zone  are  best 
considered  in  a  later  section,  but  there  are  certain  points  which 
must  be  taken  here.  A  change  in  the  character  of  gold  ores  as  they 
pass  upwards  into  the  zone  of  oxidation  is  effected  by  the  removal  of 
the  base  matter,  thus  leaving  the  gold  free.  Though  no  direct  proof 
of  the  existence  of  gold  in  vadose  solutions  has  yet  been  offered,  it  is 
reasonably  certain  that  when  chemical  changes  are  effected  in  the 
base  associates  of  gold,  some  at  least  of  the  latter  ordinarily  passes 
into  solution,  and  is  carried  elsewhere  to  be  re-deposited,  generally, 
indeed,  to  increase  the  bulk  of  already-deposited  particles  of  gold, 
and  to  assume  crystalline  form  wherever  possible.  The  zone  of 
oxidation  is,  therefore,  for  gold,  also  that  of  crystallization.  It 
is  only  in  propylitised  andesitic  country,  or  in  the  upper  portions  of 
gold-quartz  veins,  or,  as  we  shall  see  later,  in  alluvial  drifts,  that 
crystallized  gold  is  formed.  It  may  be  conceived  that  this 
restriction  arises  from  the  lack,  in  the  zone  of  cementation,  of  free 
space  necessary  for  the  operation  of  the  forces  of  crystallization, 
for,  as  we  have  seen,  free  gold  may  readily  form  in  the  deeper  zones. 

Due  to  Chemical  Action  at  the  Surface. — Experience  has 
abundantly  demonstrated  a  notable  enrichment  of  gold  veins  at  and 
near  their  outcrops,  and  it  has  been  assumed  that  much  of  the  gold 
taking  part  in  the  enrichment  is  probably  transported  in  solution. 
It  is  evident  that  such  solutions  may  pass  from  the  vein-fissures, 
which  often  act  as  the  drainage  channels  of  the  region,  to  the  rock 
surface,  and,  finally,  into  overlying  soils  and  gravels.  In  the  soils 
they  are  speedily  decomposed  by  carbonaceous  matter  ;  but  in  the 
gravels,  which  are  composed  for  the  most  part  of  chemically  inactive 
silica,  metalliferous  solutions  may  be  carried  considerable  distances 


NUGGETS.  81 

before  parting  with  their  metallic  content.  Where,  however,  they 
encounter  a  grain  of  a  precipitant,or  a  cross-current  of  a  precipitating 
solution,  or  suffer  a  physical  change  sufficiently  great,  deposition 
in  the  gravel  will  ensue.  Gold  may  thus  be  deposited  in  alluvial 
gravels.  Like  mechanically-deposited  gold,  gold  deposited  from 
solution  will  be  found  on  the  down-stream  side  of  the  auriferous 
vein-fissure.  The  arguments  for  the  chemical  origin  of  alluvial 
gold  have  been  in  the  main  advanced  by  Australian  geologists  and 
chemists  (C.  S.  Wilkinson,0  Selwyn,^  Uhlrich,c  Daintree,0"  Skey,e 
J.  Cosmo  Newbery,/  and  others),  and  by  Egleston?  in  America. 
They  are,  briefly  :  (a)  Great  masses  of  solid  homogeneous  gold  com- 
parable in  size  to  nuggets  are  rare  in  veins  ;  (6)  the  purity  of 
alluvial  gold  is  always  greater  than  that  of  the  gold  of  the  neigh- 
bouring veins  ;  (c)  gold  nuggets  are  often  frosted  with  fine  gold 
on  their  surfaces  ;  (d)  pyrites  replacing  organic  matter  in  alluvial 
drifts  is  often  auriferous  ;  (e)  laboratory  experiments  have  shown 
that  gold  is  readily  soluble  in  reagents  that  may  well  be  supposed 
to  exist  in  nature.  While  no  single  one  of  the  foregoing  arguments 
is  in  itself  conclusive,  they,  nevertheless,  taken  together,  furnish 
strong  grounds  for  the  assumption  of  the  transport  of  gold  in  solu- 
tion. Masses  of  gold  enclosing  a  considerable  quantity  of  quartz, 
but  withal  more  valuable  than  the  largest  nugget  recorded,  have 
been  obtained  from  gold-quartz  veins.  A  mass  of  golden  quartz 
630  pounds  in  weight  and  containing  gold  to  the  value  of  £12,000 
was  obtained  in  1872  at  the  Hillend  goldfield,  New  South  Wales. 
The  opponents  of  the  hypothesis  of  the  growth  of  gold  in  situ  point, 
and  with  some  considerable  reason,  to  this  and  to  similar,  though 
smaller,  masses  of  gold  as  competent  to  furnish,  after  the  removal 
of  the  quartz  by  the  battering  action  of  stream  pebbles,  the  nuggets 
of  alluvial  drifts. 

It  is  universally  admitted  that  the  purity  of  alluvial  gold  is 
greater  than  that  of  the  veins  of  the  neighbourhood.  This 
superiority  in  fineness  is  explained  by  the  well-known  fact  that 
silver  is  more  readily  soluble  in  natural  waters  than  gold,  and  is 
by  them  removed  from  the  natural  alloy,  thus  increasing  its  purity. 
This  argument,  while  certainly  valid,  fails  to  explain  the 
homogeneity  of  nuggets,  which  are,  so  far  as  has  been  ascertained, 
of  even  fineness  throughout.     Laboratory  experience  in  "  parting  " 

°  Trans.  Roy.  Soc.  Vict.,  VIII,  1866,  p.  11. 

b  Geol.  Mag.,  Ill,  1866,  p.  457. 

c  Contrib.  Min.  Victoria,  Melbourne,  1870. 

^Rep.  Geol.  Ballan,  Melbourne,  1866. 

e  Trans.  N.  Z.  Inst.,  V,  1872,  p.  377. 

./'Trans.  Roy.  Soc.  Victoria,  IX,  1867,  p.  52. 

9  Trans.  Amer.  Inst.  M.E.,  IX,  1881,  p.  646. 


82  SECONDARY  AURIFEROUS    DEPOSITS. 

silver  from  gold  has  indicated  that  unless  the  silver  constitutes  at 
least  two-thirds  of  the  bullion,  the  outside  of  the  nugget  will  alone 
be  attacked,  and  the  depth  of  alloy  affected  by  passing  solutions  is 
here  considered  to  be  too  small  to  exercise  an  appreciable  effect. 
Nevertheless,  some  attention  must  be  directed  in  this  respect 
towards  the  work  of  Liversidge,  who  found  that  the  interior  of 
nuggets  is  often  spongy  and  at  times  even  cavernous.  It  is  possible 
that  some  part  of  the  sponginess  is  due  to  the  removal  of  silver. 
Further,  a  consideration  of  the  fineness  of  the  alluvial  gold  along 
the  course  of  any  given  stream  leads  us  to  the  conclusion  that  the 
greater  purity  of  large  masses,  as  nuggets,  is  not  due  to  the  solvent 
action  of  passing  waters.  It  is  found  that  the  purity  of  alluvial 
gold  is  generally  in  inverse  proportion  to  the  size  of  the  grain,  and 
is  consequently  in  direct  proportion  to  the  distance  the  gold  has 
travelled  down  stream.  This  relation  is  simply  explained  by  con- 
sidering the  greater  surface  presented  to  agents  of  solution  by  the 
further-travelled  and  consequently  smaller  grains.  This  fact  has 
long  been  known,  and  was,  indeed,  pointed  out  by  Pliny.a  It  was 
also  known  to  Oveido,  the  companion  of  Colombus,  and  has  been 
advanced  by  recent  authorities. b  It  may  be  assumed,  therefore, 
that  solvents  of  silver  could  have  exercised  little  effect  in  raising 
the  fineness  (in  tenor)  of  the  great  masses  of  gold,  seeing  that  so  far 
as  the  facts  go  they  show  that  such  solvent  action  is  operative  to 
an  appreciable  extent  only  when  the  grains  of  gold  become  very 
small.  In  regions  as  Alaska  and  Siberia,  where  oxidation  is  scanty 
and  acid  waters  are  not  abundant,  meteoric  waters  may  exercise 
little  effect  even  on  the  surface  of  nuggets.  The  low  tenor  (750-800) 
of  Klondike  nuggets  may  be  attributed  in  small  part  to  this  cause. 
The  frosting  of  the  surfaces  of  nuggets  is  attributed  by  the 
opponents  of  the  chemical  theory  to  the  etching  action  of  perco- 
lating waters  on  gold  surfaces.  As  will  be  seen  later,  this  assump- 
tion is  opposed  to  the  evidence  and  to  the  laws  governing  the 
solution  of  crystals.  The  validity  of  the  fourth  argument,  viz., 
that  the  presence  of  auriferous  pyrite  replacing  woody  fibre 
in  alluvial  drifts  indicates  deposition  from  solution  is  generally 
admitted,  but  it  is  urged  that  it  has  no  obvious  bearing  on 
the  growth  of  metallic  gold.  Numerous  examples  of  pyritous 
replacements  of  tree  stems  have  been  recorded  from  the 
alluvial  drifts  both  of  Victoria  and  of  California.  Many  of  these 
replacements  are  auriferous,  and  the  gold  is  assumed  to  have  been 
deposited  from  solution  by  the  well-established  reducing  action  of 
pyrite.     Newbery  also  found  gold  in  the  ashes  of  timbers  taken 

«Hist.  Nat.,  Lib.  XXVIII,  Cap.  21. 

b  Ross  Browne,  Eng.  Min.  Jour.,  Feb.  2,  1895. 


NUGGETS..  83 

from  alluvial  drifts.  The  bearing  on  the  question  at  issue  of  the 
fifth  argument,  which  makes  an  analogy  between  re-actions  in  nature 
and  in  the  laboratory,  is  not  admitted  by  the  supporters  of  the 
mechanical  hypothesis. 

The  foregoing,  in  brief,  represented  the  position  of  the  con- 
troversy in  the  early  'eighties,  and  the  hypothesis  of  formation  of 
nuggets  from  solutions  in  drifts  was  considered  well  established. 
The  conclusions,  rather  than  the  work,  of  Liversidge  have,  however, 
done  much  to  unsettle  this  position.  Liversidge  cut  many  nuggets 
into  sections,  etching  with  aqua-regia  the  flat  surfaces.  These 
showed,  when  thus  treated,  a  well-defined  crystalline  structure, 
which  appeared  to  be  the  more  perfect  as  the  quality  of  the 
gold  improved.  Nevertheless  Liversidge  concluded01  that 
nuggets  are  derived  entirely  and  directly  from  veins,  and  that 
;'  any  small  addition  they  may  have  derived  from  meteoric  water  ': 
is  quite  immaterial  and  may  be  neglected.  Apparently  his  diffi- 
culty in  the  acceptance  of  the  rrypothesis  of  the  growth  of  gold  in 
situ  in  gravels  arose  from  his  anticipation  that  nuggets,  were  they 
of  meteoric  growth,  would  show  concentric  or  curvilaminar  zones 
of  growth  arranged  like  the  shells  of  an  onion.  Such  concentric 
coatings,  however,  are  probably  only  possible  when  growth  takes 
place  with  abnormal  rapidity.  Two  such  nuggets  from  New 
Guinea  have  been  described,  showing  distinct  agate-like  lines  of 
growth,  with  no  signs  of  crystalline  structure,6  but  all  others  ex- 
amined show  more  or  less  completely  the  crystalline  character  of 
Plate  II,  a  character  entirely  in  accordance  with  all  that  we  know 
of  the  slow  growth  of  crystalline  bodies  from  dilute  solutions.  The 
internal  homogeneous  crystalline  structure  must  certainly  be  con- 
sidered an  argument  in  favour  of  growth  in  situ.  Evidence  is 
accumulating  in  favour  of  this  view.  Definite  examples  of  the 
deposition  of  gold  in  situ  in  gravels  are  still  rare,  but  there  can  be  no 
doubt  that  to  this  class  belongs  the  crystallized  gold  of  Kanowna, 
Western  Australia,  where  tiny,  yet  bright  and  sharply-defined 
octahedral  gold  crystals  occur  in  the  so-called  "  pug  "  or  ancient 
clayey  gravel.  They  have  obviously  undergone  no  attrition  such  as 
they  must  have  suffered  had  they  been  of  detrital  origin.  It  is 
interesting  to  note  that  Maitlandc  considers  these  crystals  to  be 
identical  in  origin  with  those  found  in  the  oxidised  portions  of 
adjacent  and  underlying  veins,  a  view  entirely  in  accord  with  that 
adopted  in  this  treatise.  An  even  more  striking  instance  is  recorded 
from  the  Klondike  region  of  Canada  .d       In  Miller  Creek  a  well- 

a  Jour.  Roy.  Soc.  N.  S.  W.,  XXVII,  1893,  p.  343  ;    lb.,  XXXI,  1897,  p.  79. 

b  Liversidge,  Jour.  Roy.  Soc.  N.  S.  W.,  XL,  1906,  p.  161. 

cAnn.  Prog.  Rep.  Geol.  Surv.  W.  A.,  1899,  p.  9. 

^McConnell,  Ann.  Rep.  Geol.  Suit.  Canada,  XIV,  1901,  p.  64b. 


84  SECONDARY    AURIFEROUS    DEPOSITS. 

rounded  quartz-pebble  or  boulder  was  found  carrying  on  its  upper 
surface  numerous  thin  specks  and  scales  of  crystallized  gold  dendri- 
tically  arranged.  Spurr"  quotes  a  somewhat  similar  case  from 
the  placers  of  Providence  Hill,  Plumas  Co.,  California,  where  nearly 
perfect,  and  only  slightly  worn  crystals  of  magnetite  were  covered 
by  a  thin  film  of  gold.  The  sections  of  nuggets  made  by  Liversidge 
show  that  nuggets  are  often  spongy  and  cavernous,  and  may  con- 
tain appreciable  quantities  of  quartz,  ferruginous  oxides,  and 
argillaceous  master.  The  specific  gravity  of  a  nugget  of  marked 
spongy  character  was  only  15-21.  Nuggets  of  gold  from  Klondike 
though  only  750  fine  showed,  in  general,  the  same  characters  as  the 
purer  Australian  nuggets.  In  a  later  paper6  the  same  authority, 
to  whom  we  are  indeed  indebted  for  all  our  knowledge  on  the 
internal  structure  of  nuggets,  shows  that  apparently  simple  gold 
crystals,  such  as  well-formed  rhombic  dodecahedra  from  New  South 
Wales,  on  etching  yield  ample  evidence  that  they  are  not  internally 
homogeneous  but  are  in  reality  highly  complex,  and  are  composed  of 
a  number  of  individuals. 

From  the  present  point  of  view,  the  most  potent  argument 
in  favour  of  the  growth  of  gold  in  gravels  is  one  on  which,  for  various 
reasons,  no  emphasis  has  previously  been  laid,  viz.,  that  by  far  the 
largest  and  best  examples  of  crystallized  gold  have  been  obtained 
from  alluvial  drifts.  (See  Frontispiece.)  The  general  absence  of 
crystallized  gold  from  the  placers  of  California  has  led  many  to  the 
inference  that  it  never  does  so  occur.  Newberry  (J.  S),  for  example, 
says  :  '  Crystals  are  never  found  in  placer -gold  nor  are  sheets 
or  threads."  The  evidence  furnished  by  the  placer  gold  of  Klondike, 
the  Urals,  Victoria,  Western  Australia,  and  other  fields  is  sufficient 
refutation  of  the  foregoing  statement.  Wire-gold,  according  to 
Gordon,0  was  common  at  the  surface  in  the  early  diggings  of  Otago, 
New  Zealand,  and  was  by  the  diggers  considered  to  be  grass-roots 
replaced  by  gold.  The  wires  were  often  broadened  to  plates  ; 
they  were  smooth  or  striated  and  were  occasionally  dusted  with 
small  cubical  crystals  of  gold.  Of  the  many  specimens  of  native 
crystallized  gold  examined  by  the  writer  during  the  past  ten  years, 
few  derived  from  the  oxidised  portions  of  veins  have  approached 
either  in  size  or  in  crystallographic  perfection  of  the  individual 
those  obtained  from  placer  deposits.  The  latter  present  an  aspect 
entirely  characteristic,  indicated  generally  as  a  tendency  towards 
isolation  of  the  individual  crystal,  and,  what  is  probably  a  corollary, 
towards  the  assumption  of     ideally  simple  cubical  or  octahedral 

«  18th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  Ill,  1896-7,  p.  378. 
b  Jour.  Roy.  Soc.  N.  S.  W.,  XLI,  1907,  p.  143. 
c  Trans.  Amer.  Inst.  M.E.,  XXV,  1895,  p.  294. 


Plate  11. 


I^BfeJ&fc 


Polished  and  etched  sections  oe  Gold  Nugget,  Coolgardie,  Western  Australia  (Liversidgi ). 

(Enlarged  2  diameters.) 


CRYSTALLIZED    GOLD.  85 

forms.  This  facies  is  to  be  attributed  to  accretion  of  metal  from  an 
enveloping  solution,  a  condition  that  is  rarely  possible  in  veins 
where  regular  crystal  growth  is  further  hindered  by  the  influence 
of  vein  walls  or  of  associated  solid  crystal  precipitants  (as  galena 
or  pyrite),  which  affect  the  local  supersaturation  of  the  auriferous 
solution  in  the  neighbourhood  of  the  growing  crystal.  The  numerous 
solid  angles  of  the  gold  crystals  thus  deposited,  by  counter-attraction 
within  the  solution,  further  operate  to  intercept  the  solid  matter 
that  would  otherwise  build  up  a  single  well-defined  crystal.  The 
general  character  of  crystallized  gold  from  veins  is  consequently 
that  of  an  irregular  mass  showing  numerous  small,  distorted,  and, 
within  crystallographic  limits,  unlike  faces.  Large  specimens  of 
crystallized  gold,  such  as  those  described  by  the  writer  and  others, 
do  occur  in  veins,  but  they  are  so  distorted  either  by  flattening 
or  by  elongation,  that  they  could  not  possibly  withstand  the  abrasion 
to  which  they  must  certainly  be  subjected  before  finally  coming  to 
rest  in  gravels.  Further,  were  the  gold  crystals  of  placers  derived 
from  veins  they  must  be  of  the  same  character  and  of  the  same  or 
less  size.  We  have  seen  that  they  differ  in  character,  and  are 
greater  in  size.  The  occasional  presence  of  small  quantities  of 
quartz  enclosed  in  the  interior  of  nuggets  is  not  in  itself  an  evidence 
of  vein  origin  since  it  is  conceivable  that  a  nugget  may  in  the  course 
of  its  growth  enclose  grains  of  quartz.  Where,  however,  the  quartz 
so  enclosed  is  sharp  and  angular,  a  detrital  origin  for  the  gold  is 
indicated.  Even  where  nuggets  have  not  been  entirely  deposited 
from  solutions,  it  is  possible  that  they  may  owe  their  massive  form 
to  filling  of  interstices  by  gold  attracted  by  mass-action  from 
solution  and  deposited  in  cavities  and  crevices  of  detrital  nuggets. 
Such  accretion,  from  our  knowledge  of  crystal  growth,  will  probably 
take  place  in  accordance  with  the  direction  of  the  crystallographic 
axes  of  already-formed  crystals,  and  the  new  deposit  may,  to  a 
limited  extent,  and  until  interfered  with  by  the  influence  of  adjacent 
crystals,  be  in  crystallographic  continuity  with  the  older  crystal. 
Close  and  exhaustive  examination  by  assay  of  the  variation  in 
internal  composition  of  gold  nuggets  would  throw  considerable 
light  on   the  origin  of  nuggets,    and    is   greatly   to  be  desired. 

The  high  gold  tenor  of  certain  pyrite  deposits  in  the  gravels 
of  Southern  Siberia,  of  British  Columbia,  and  elsewhere,  suggests 
the  possibility  of  some  of  the  placer  gold  of  those  regions  having 
been  derived  directly  from  the  decomposition  of  auriferous  pyrite, 
itself  probably  of  secondary  origin. 

It  has  been  stated  that  sharp,  well-defined,  crystal  edges  are 
regarded  as  evidence  of  growth  in  situ  ;  the  converse,  that  rounded 
edges  with  curved  faces  may  be  taken  to  denote  solution,  is  only 


86  SECONDARY   AURIFEROUS    DEPOSITS. 

partially  true,  since  this  result  is  also  attained  by  attrition.  Never- 
theless, certain  crystals  have  been  observed  whose  rounded  edges 
are  too  regular  to  be  ascribed  to  pounding  or  rubbing,  and  these 
are  perhaps  to  be  considered  attempts  to  approach  the  ideal  sphere 
that  theoretically  results  when  isometric  crystals  are  attacked 
by  solvents. a 

The  final  conclusions  to  which  the  writer  has  been  brought  with 
regard  to  the  much-vexed  question  of  the  origin  of  alluvial  gold  are 
therefore  that  growth  of  gold  on  gold  or  on  other  nuclei  is  possible, 
and  takes  place  wherever  and  whenever  ionized  or  other  auriferous 
solutions  pass  through  gravels  furnishing  the  conditions  of  pre- 
cipitation ;  and,  further,  that  no  real  distinction  in  origin  or  method 
of  formation  may  be  made  between  the  gold  so  deposited  and 
that  of  the  oxidised  zones  of  gold  veins,  the  differences  above- 
noted  being  merely  due  to  environment. 

Secondary  Auriferous  Deposits  Arising  from  Mechanical 
Action. — While,  therefore,  there  remains  but  little  doubt  that 
some  placer  gold  owes  its  origin  to  accretion  from  auriferous  solutions 
percolating  through  gravels,  it  is  nevertheless  probable  that  by 
far  the  larger  portion  of  the  gold  recovered  from  placers  is  of  detrital 
origin,  and  has  been  derived  directly  from  gold-quartz  veins,  and 
especially  from  those  veins  hi  which  the  gold  is  already  coarse. 
Speaking  generally,  the  richness  of  a  placer  deposit  is  governed 
rather  by  the  physical  conditions  of  deposition  and,  to  a  minor 
extent,  by  the  character  of  the  gold  of  the  parent  matrix,  than 
by  the  tenor  of  that  matrix.  Where  the  geological  history  of  any 
auriferous  area  has  admitted  of  oft-repeated  or  long-continued 
erosion  and  consequent  concentration  of  the  heavy  content  of 
gravels,  then  the  stream  beds — modern  and  ancient — are  of  economic 
value.  Thus  the  gold  of  the  rich  beaches  of  the  Clutha  River  in 
New  Zealand  is  derived  from  small  and  unimportant  quartz- 
veins  and  lenticles  in  the  quartz-schists  of  Central  Otago.  In  the 
Klondike  region,  despite  the  extraordinary  richness  of  the  gravels, 
the  parent  gold-quartz  veins  of  the  local  schists  are  apparently 
worthless.  Many  similar  instances  may  be  cited  ;  and  in  the 
majority  of  these  the  richness  of  the  gravels  cannot  be  explained 
by  the  assumption  that  the  placers  owe  their  value  to  the  degradation 
of  bonanza  outcrops,  for  the  formation  of  the  placers  has  taken 
place  in  comparatively  recent  times,  during  which  climatic  con- 
ditions have  not  varied  appreciably  from  those  at  present  prevailing, 
and  these,  as  in  Alaska,  British  Columbia,  and  Siberia,  are  often 
inimical  to  outcrop  enrichments.     Tyrrell  has  calculated  that  the 

"Fock,  "Chemical  Crystallography,"  London,  1895,  p.  61. 


SOURCE    OF   ALLUVIAL    GOLD.  87 

gold  of  the  Klondike  gravels  may  be  considered  to  be  derived 
from  900  feet  of  eroded  country,  or  a  total  quantity  of  1  •  6  billion 
(English)  tons  of  rock.  Assuming  the  gravels  to  contain 
10,000,000  ounces  of  gold,  the  average  gold  content  of  the  schist 
removed  has  been  only  -003  grain  gold.  On  the  other  hand, 
exceedingly  rich  vein-deposits  may  give  no  shoadings,  and 
therefore  no  hint  of  their  existence.  The  bonanza  outcrops 
of  the  Coromandel  and  Thames  goldfields,  in  a  country  where 
conditions  are  peculiarly  favourable  to  surface  enrichment, 
yielded  insignificant  quantities  of  alluvial  gold.  On  the  eastern  or 
Tokatea  slopes  of  the  mountain  range  at  Coromandel,  on  which 
the  rich  Royal  Oak  and  other  veins  outcropped,  not  a  single  colour 
could  be  obtained  by  panning,  nor  were  nuggets  found  in  the  streams 
below.  The  famous  Martha  system  of  the  Waihi  mine,  that  has  yielded 
nearly  seven  millions  sterling  from  the  uppermost  900  feet  alone, 
gave  no  alluvial  gold,  although  physical  conditions  were  exceedingly 
favourable  for  concentration.  In  this  case,  however,  there  was  no 
surface  enrichment,  and  the  gold  of  the  veins  is  in  a  state  of  extremely 
fine  division.  The  rainfall  is  heavy,  and  the  gold  in  solution  that 
would  normally  have  formed  a  surface  enrichment  was  carried  into 
the  surface  waters  and  widely  dispersed.  The  sheddings  also  from 
the  famous  Witwatersrand  "  banket '  deposit  were  trifling  in 
quantity.  These  instances  are  sufficient  to  show  that  the  richness 
of  a  placer  deposit  is  not,  of  necessity,  dependent  on  the  richness 
of  the  parent  source. 

Placers. — The  gold-quartz  of  the  outcrops  of  quartz-veins 
is  freed  from  the  parent  body  by  erosion  and  passes  either  at  once 
into  a  stream-bed  or  reaches  the  latter  after  a  slow  journey  down 
the  hill-slopes,  where  its  progress  towards  the  valley  bottom  is 
dependent  on  the  supply  of  running  water  and  on  the  "  creep" 
of  the  hiU-side.  Where  the  slopes  are  flat  a  certain  amount  of  gold 
concentration  may  take  place  in  the  soil  of  the  hill-side  below  the 
vein  outcrop  by  the  readier  removal  of  associated  quartz.  These 
deposits  (bergseifen)  are  not  of  great  economic  value,  and  have 
been  noted  mainly  in  tropical  countries  (Borneo,  &c).  Akin  to 
them  are  the  shallow  surface  deposits  of  dry  desert  countries  where 
wind-action  has  removed  the  lighter  grains  of  quartz.  Both  these 
types  are  in  themselves  of  little  economic  importance,  but  are 
invaluable  as  indicating  the  near  proximity  of  the  parent  vein. 

Rivers  erode  their  beds  so  long  as  their  waters  possess  sufficient 
velocity  to  keep  the  river  bottom  clear  of  gravel.  When  this  is 
no  longer  the  case,  and  permanent  deposition  of  material  is  the 
characteristic  feature  of  any  part  of  a  river  system,  that  part  is 
said  to  have   reached  base   level.     Cessation   of  eroding  activity 


88  SECONDARY   AURIFEROUS    DEPOSITS. 

obtains  first  in  the  lower  part  of  a  river  course,  but  erosion  may 
theoretically  be  continued  in  its  headwaters  and  numerous  branching 
and  sub-branching  tributaries  until  the  whole  country  is  reduced 
to  base-level,  and  becomes  so  low,  and  the  velocity  of  the  streams 
is  so  far  reduced,  that  erosion  is  no  longer  possible.  This  condition 
is,  however,  not  of  general  occurrence  in  nature,  for  regions  are 
rarely  stationary,  and  their  surface  slowly  rises  or  falls  in  respect 
to  sea-level.  In  a  region  of  depression  base-level  is  naturally 
reached  much  sooner  than  would  otherwise  be  the  case.  In  a  region 
of  elevation,  gradient  is  always  being  restored  and  the  active  life  of 
the  river  prolonged.  The  general  principles  governing  the  life- 
history  of  rivers  are  of  some  importance  from  our  present  stand- 
point, since  the  gold  and  gravel  are  generally  simultaneously 
deposited,  and  are  subjected  to  the  same  natural  laws. 

Deposits  of  auriferous  alluvial  gravels  are  termed  placers, 
alluvial  drifts,  or  more  simply,  "  alluvials."  The  first  term  is  of 
Spanish  origin,  and  is  used  mainly  in  America  ;  the  two  latter 
obtain  in  Australia.  Their  gold  is  generally  readily  accessible  to 
the  individual  miner,  and  is  easily  recovered  by  the  simplest  of 
means.  They  have,  therefore,  furnished  a  very  large  proportion 
of  the  world's  gold  supply,  and  for  the  same  reason  are  the  earliest 
of  the  gold  deposits  worked.  Their  richness,  in  California,  Victoria, 
New  Zealand,  and  the  Klondike,  has  at  times  been  extraordinary. 
Often  in  Victoria  yields  of  250  ounces  gold  per  bucket  of  gravel 
have  been  obtained. 

The  upper  portions  of  rivers  form  natural  sluices,  where,  owing 
to  the  velocity  of  the  stream,  gravel  deposits  are  rare,  coarse,  and 
thin.  The  earliest  permanent  deposit  of  gravel  takes  place  when 
the  gradient  of  a  stream  becomes  sufficiently  flat  or  the  valley 
widens  so  that  the  waters  of  the  stream  are  no  longer  confined. 
In  the  latter  case,  a  "  fan  "  results  at  the  debouchure  of  the  stream 
from  the  narrow  into  the  broader  valley  or  into  the  plains.  They 
are  especially  characteristic  of  tropical  and  other  rivers  subject 
to  periodic  high  floods.  Rivers  debouching  from  the  Himalayas  into 
the  Gangetic  and  Brahmaputra  plains  show  this  feature  especially 
well,  gold  and  coarse  gravel  being  deposited  only  within  a  short 
distance  of  the  debouchure.  Further  out,  sand,  and  still  further, 
fine  mud,  are  deposited.  Owing  to  changes  in  the  direction  of  rivers 
or  in  the  level  of  river  valleys,  gravels  may  be  covered  by  sands 
or  clays,  and  those  again  by  gravels.  Since  gold  is  deposited  with 
gravels,  there  may  therefore  occur  in  the  history  of  the  alluvium  of 
any  given  valley,  two  or  more  periods  of  auriferous  deposition. 

It  may  be  stated  as  a  general  rule  that  the  deposition  of  gold 
in  gravels  arises  from  a  diminution  in  the  velocity  of  the  trans- 


PLACER  GRAVELS. 


89 


porting  waters.  The  diminution  may  be  general,  as  in  the  case 
above-mentioned,  or  may  be  local.  The  latter  occurs  when  the 
river  crosses  the  strike  of  schistose  or  slaty  strata,  the  upturned 
edges  of  which  act  as  natural  riffles,  the  gold  being  deposited  in  the 
crevices  of  the  slate  or  schist.  The  down-stream  side  of  a  rocky 
bar  is  for  the  same  reason  a  convenient  lodging  place  for  auriferous 
gravels,  as  also  is  the  inner  or  concave  side  of  a  river  bend.  An 
uneven  bottom  is  favourable  to  deposition,  and  a  soft  bottom  is 
likely  to  retain  more  gold  than  a  hard  one. 

A  marked  concentration  of  gold  is  observable  towards  the 
bottom  of  placer  gravels,  the  richest  deposits,  as  a  rule,  lying  on 
"  bed-rock."     Where,  however,  conditions  have  permitted,  without 


'l|i\V'/'lll\\\N-///|n^W///l,r.^    '<Mll^      '/,/nu^  "//|n^"mV^",Y 


£'<!,'{&:  :^','   ■.■£'.!:  *"  !/^\"''/^i///Sai; 


Fig.  67.    Showing  Gbavels  Deposited  by  a  Meandering  River  (Spurr). 

prior  scouring  of  the  bed,  deposition  on  clays  or  on  cemented  sands, 
the  upper  surfaces  of  these  prevent  the  downward  progress  of  gold, 
and  are  then  known  as  "  false  bottoms." 

The  motion  of  a  grain  of  gold  in  course  of  transport  along 
a  stream  bed  is  neither  forward  horizontally  due  to  the  force  of 
the  stream  current  nor  downwards  vertically  due  to  the  force 
of  gravity,  but  is  in  a  direction  compounded  of  the  two.a  Lateral 
currents  may  tend  to  deflect  the  falling  grain  sidewise,  forming 
deposits  on  the  beaches  of  the  inner  or  concave  side  of  the  river. 
It  has  recently  been  shown  that  the  course  of  stream-waters  is 


a  Park,  Bull.  N.Z.  Geol.  Surv.,  Xo.  5,  1908,  p.  36. 


90  SECONDARY    AURIFEROUS    DEPOSITS. 

spiral  when  passing  round  river  curves,"  thus  explaining  the  deposit 
on  the  inner  side,  since  the  lower  part  of  the  spiral  flow  is  from 
the  deep  outer  to  the  shallow  inner  bank.  The  stream  itself  com- 
bining a  progressive  with  a  lateral  motion  may  thus  be  said  to 
screw  itself  like  a  corkscrew  round  a  bend.  The  fall  of  gold  in 
gravel  is  not,  of  course,  continuous,  but  takes  place  only  on  dis- 
turbance of  the  gravel.  This  is  generally  effected  by  the  force 
of  the  stream  current.  It  has  recently  been  suggested b  that  the 
necessary  disturbance  of  the  gravel  is  effected  during  a  downward 
"  creep  "  of  the  valley  gravels  entirely  comparable  to  that  well 
known  to  occur  on  hill-sides.  Where  gravels  are  absent  from  a 
stream  bed  owing  to  scour,  there  also  gold  is  wanting.  Rocky 
potholes,  contrary  to  the  general  belief,  rarely  contain  gold.  Coarse 
gold  is  certainly  caught  in  them,  but  the  continuous  grinding  of 
the  stones  generally  to  be  found  in  these  holes  soon  reduces  it  to 
powder,  in  which  state  it  is  readily  carried  away  by  the  swirl  of 
the  waters. 

Local  enrichment  of  gravels  may  take  place  below  the  junction 
of  two  auriferous  valleys,  or,  as  is  often  the  case,  below  the  outcrop 
of  gold-veins  crossed  by  the  stream.  A  general  relation  between 
the  coarseness  of  gold  grains  and  of  gravel  may  be  made  out  for 
most  regions,  fine  gold  occurring,  as  might  be  expected,  with  the 
finer  gravel  ;  it  is  possible  that  examination  might  establish  a 
fairly  constant  ratio.  For  the  same  reason  "  black  sand,"  containing 
magnetite,  ilmenite,  garnet,  and  other  heavy  minerals,  is  a  common 
associate  of  gold  in  gravels. 

Ideal  rivers  for  the  concentration  of  gold  are  those  in 
which  natural  conditions  approach  most  closely  those  of  a  long 
sluice ;  they  therefore  possess  even,  rapidly-flowing  waters,  have  a 
regular  gradient,  and  are  at  times  subject  to  minor  floods.  These 
conditions  are  practically  fulfilled  only  in  temperate  zones.  In 
tropical  countries  subject  to  monsoons,  where  rivers  are  in  -high 
flood  during  a  portion  of  the  year,  and  are  dry  or  nearly  so  during 
the  remainder,  the  continuous  concentration  necessary  to  yield 
placer  deposits  of  economic  value  is  absent.  Deposition  of  gold 
in  these  regions  takes  place  only  after  the  monsoon  or  rainy  season, 
when  the  rivers  are  falling  and  when  the  boulders  and  pebbles 
on  the  surface  of  the  gravels  furnish  convenient,  but  local,  riffles. 
Under  these  conditions  gold  is  deposited  only  in  the  tiny  eddies 
formed  by  the  passage  of  the  falling  flood  waters  over  deposits 
of  coarse  gravel.  It  therefore  occurs  at  the  heads  and  tails 
of  gravel  banks  and  islands  in  the  river-bed,  and  on  the  beaches 

a Lodge,  "Nature,"  Nov.  7,  1907,  p.  7. 
&Min.  Sci.  Press,  Aug.  15,  1908. 


FLOOD    GOLD.  91 

of  the  inner  sides  of  the  river  curves.  The  gold  deposits  are 
rarely  more  than  a  few  inches  below  the  surface  of  the  gravel, 
and  those  formed  at  the  close  of  a  rainy  season  are  scattered  deep 
and  wide  by  the  monsoon  floods  of  the  ensuing  season.  Many 
economic  investigations  have  failed  from  neglect  to  recognise 
the  impossibility,  under  the  foregoing  conditions,  of  'bottom" 
concentration. 

Surface  concentration  entirely  akin  to  the  above  takes  place 
locally  and  to  a  limited  extent  in  many  rivers  in  temperate  regions, 
but  in  these  rivers  by  far  the  greater  portion  of  the  gold  is  deposited 
on  or  near  a  "  bottom,"  false  or  true,  as  a  necessary  consequence 
of  the  persistence,  perhaps  for  centuries,  of  a  stream  in  the  same 
restricted  channel. 

Beach  Sands.— Marine  placers  are  the  only  other  form  of 
auriferous  alluvial  deposit  requiring  notice  in  this  section.  They 
are  confined  almost  entirely  to  the  shores  of  the  Pacific  Ocean,  but 
their  occurrence  on  the  coasts  of  Nova  Scotia,  Ireland,  and  Portugal 
shows  that  the  foregoing  restriction  is  purely  coincidental.  They 
perhaps  attain  their  greatest  development  on  the  west  coast  of 
the  South  Island  of  New  Zealand,  on  the  beaches  of  Oregon, 
and  below  Port  Arthur  on  the  Liau-Tung  Peninsula.  The 
richest  beach  sands  known  appear  to  have  been  those  of  the  Gold 
Bluff,  Klamath  County,  Oregon,  where  narrow  beaches  at  the 
foot  of  overhanging  bluffs  serve  as  concentrating  floors  for  the 
auriferous  sands  thrown  within  reach  of  the  ocean  waves  by  cliff 
falls.  Concentration  on  these  beaches  takes  place  only  when  the 
surf  strikes  the  shore  line  at  an  acute  angle  ;  when  the  surf  beats 
at  right  angles  gravel  -and  sand  are  cast  up.  The  process  of  con- 
centration is  simple  :  the  strong  surf  casts  up  gold,  gravel,  heavy 
minerals,  and  sand,  while  the  weaker  and  less  rapidly  flowing 
undertow  removes  only  the  sand  and  lighter  stones.  With  the 
gold  is  generally  associated  much  black  sand.  On  the  auriferous 
marine  beaches  of  New  Zealand  pebbles  or  stones  are  absent,  and 
the  gold  is  contained  entirely  in  "  black  sand."  The  distribution 
of  beach  sands,  both  in  time  and  place,  is  erratic,  the  requisite 
degree  of  concentration  being  generally  attained  only  after  heavy 
storms.  Once  formed,  beach  deposits,  when  being  worked  for 
their  gold  content,  are  immediately  removed  beyond  the  reach  of 
subsequent  storms,  since  these,  if  coming  from  a  slightly  different 
direction,  destroy  the  previously  formed  deposit.  South-west  gales 
are  in  New  Zealand  considered  the  most  favourable  for  the  production 
of  rich  layers  of  black  sand.  The  gold  of  these  deposits  is  invariably 
flaky  ;  that  of  Oregon  is  often  bi-concave  with  well-defined  rims, 
due  possibly  to  rolling  edgewise  when  moving  up  and  down  the 


92  SECONDARY   AURIFEROUS    DEPOSITS. 

beach.  The  deposits  of  Oregon  are  continued  north  to  Washington 
and  south  to  California.  Other  notable  beach  placers  are  those  of 
Carelmapu  and  Punta  Arenas,  Chili  ;  the  shores  of  the  Sea  of 
Okhotsk  ;  at  Unga  Island,  Nome,  and  Cape  Yagtag,  Alaska  ;  and 
on  the  northern  coast  of  New  South  Wales.  Those  of  Cape  Yagtag 
are  remarkable  in  that  they  carry  garnet  without  the  ordinary 
associates  of  gold  in  beach  sands,  viz.,  magnetite  and  ilmenite. 
In  Oregon  and  New  South  Wales  and  at  Nome,  ancient  auriferous 
beach  sands  are  worked  above  present  high  water  level.  At  Nome 
two  such  beaches  may  be  traced. 

Deep  Leads. — The  placer-deposits  that  have  heretofore 
been  described  are  of  recent  origin  and  lie  at  or  near  the  surface. 
Auriferous  gravels  of  greater  age  are  liable  to  be  subjected  to  all  the 
vicissitudes  of  erosion  or  sedimentation  attendant  on  orogenic 
movements  in  the  given  region.  With  depression  of  the  region 
many  hundreds  of  feet  of  sand  and  clay  may  be  superposed  on  the 
gravels.  In  the  two  principal  regions  containing  buried  placers, 
viz.,  California  and  Victoria,  the  ordinary  covering  of  alluvium  has 
been  capped  by  thick  flows  of  basaltic  lava,  and  to  this  capping 
the  ancient  gravels  of  California,  at  least,  largely  owe  their  preser- 
vation. Greatly  depressed  placers  are,  from  their  depth,  and  hence 
from  the  great  bodies  of  water  contained  in  them  and  in  the 
superincumbent  strata,  generally  economically  inaccessible  ;  it  is 
when  they  have,  in  the  course  of  great  earth-movements,  been 
elevated  above  the  permanent  water-level  of  the  country,  that  their 
gold  becomes  readily  available  to  mining.  The  buried  placers  of 
California  have  been  elevated  to  an  average  height  above  sea-level 
of  2,600  feet  along  the  western  flanks  of  the  Sierra  Nevada,  and 
have  shared  in  the  late  Tertiary  uplift  of  that  great  range.  In 
Victoria  similar  buried  gravels  are  commonly  termed  "  deep  leads." 
Akin  to  those  due  to  ancient  fluviatile  action  are  ancient  lacustrine 
auriferous  gravels,  as  those  of  the  Blue  Spur,  New  Zealand. 

It  will  be  evident  that  during  regional  depression  and  subsequent 
elevation,  the  drainage  system  of  a  country  may  be  materially 
modified.  The  modification  has  been  notable  in  California,  where 
the  existing  streams  have  intersected  the  ancient  buried  channels 
almost  at  right  angles,  and  have  cut  great  gorges  in  them,  the 
bed  of  the  present  stream  being  occasionally  1,500  feet  below  that 
of  the  ancient  channel.  In  this  way  also  great  lengths  of  the  course 
of  the  ancient  rivers  have  been  obliterated,  and  the  adjacent  country 
so  eroded  that  the  course  of  the  ancient  channel  may  now  be  traced 
only  at  intervals  high  up  on  the  flanks  of  a  mountain  range.  It 
may  even  follow  a  ridge,  a  feature  of  not  uncommon  occurrence 
when  a  basaltic  lava  flow  has  filled  an  ancient  valley.     In  this 


DEEP   LEADS. 


93 


case  the  lava  has  resisted  denudation  while  the  softer  bed-rock  of 
the  valley  sides  has  been  worn  away,  leaving  a  lava-capped  ridge, 
as  shown  in  the  accompanying  section.  (Fig.  68.)  In  the  same 
way  hill-tops  of  cemented  or  lava-topped  gravel  may  be  formed. 

In  Victoria  the  general  direction  of  river  drainage  has  not 
changed  since  the  deposition  of  the  deep  leads,  and  the  channels 
of  modern  streams  are  therefore  either  superimposed  on  the  deep 
leads  or  are  parallel  to  them.  No  great  amount  of  elevation  has 
taken  place  in  Victoria,  and  the  country  has  rather  been  subjected 
to  a  general  north  and  south  tilting,  depressing  the  lower  (northern) 
portions  of  the  channels  and  raising  the  upper  (southern)  portions. 


I 


'/////,  //////  ////// 


';///.' 


Fig.  68.     Ideal  Section   showing  Relative  Position1  of  "  Benches  "  aXd  of  Buried   River 

Channels  Covered  by  Basalt  Flow  {Hobson). 

1.  Capping  of  clay  and  soil.     2.  Auriferous  gravels.     3.  Blue  lead. 


The  tilting  has  occasionally  proceeded  so  far  as  locally  to  change 
the  direction  of  fall  of  the  bed-rock.  On  account  of  the  absence 
of  marked  regional  elevation,  the  ancient  placers  of  Victoria 
fail  to  show  the  high-level  "  benches  "  (river  terraces)  so  charac- 
teristic of  the  Calif ornian  deposits. 

The  gold  of  deep  leads,  as  might  be  expected  from  analogy  with 
the  deposits  of  modern  rivers,  is  not  evenly  distributed  through- 
out the  lead,  either  vertically  or  longitudinally.  The  deepest 
part  of  the  lead  is  termed  the  "  gutter,"  and  normally  pursues  a 
sinuous  course.  The  gutter  is  often  the  richest  part  of  the  lead, 
but  the  best  runs  of  gold  may  nevertheless,  as  in  existing  streams, 
be  contained  in  beaches  high  above  the  gutter.  Buried  "  benches  " 
are  known  along  the  course  of  deep  leads,  which  also  show  all  the 
branching  into  tributary  streams  displayed  by  modern  placers. 
The  boulders  of  the  deep  lead  gravels  of  Victoria  are,  on  the  average, 
less  than  6  inches  in  diameter.  They  may,  however,  range  up  to 
3    feet,    and,  very  rarely,  to    12  feet.      The  general  sequence  of 


94  SECONDARY    AURIFEROUS    DEPOSITS. 

strata  in  a  deep  lead  is  gravel,  sand,  and  clay,  with  often  a  car- 
bonaceous layer  overlying  the  clay  ;  this  sequence  may  be  repeated 
several  times.  The  normal  colour  of  the  chief  Calif ornian  leads  is 
blue,  from  the  presence  of  ferrous  compounds.  The  colour  changes 
to  rusty  brown  on  exposed  surfaces.  Cementation  by  ferruginous 
oxides  is  common  in  deep  leads,  the  resultant  indurated  mass  being 
termed  a  "  cement."  Notable  enrichments  occur  in  many  deep 
leads  below  the  junction  of  two  streams  and  also  below  the  inter- 
section with  auriferous  zones  or  reefs.0 

The  principal  deep  leads  of  California  lie  on  the  western  Sierra 
Nevada  ranges,  in  Yuba,  Sierra,  Placer,  and  Nevada  counties,  in 
the  region  drained  by  the  Feather,  Yuba,  and  Bear  Rivers.  A 
deep  lead  on  the  eastern  slopes  of  the  Sierra  Nevada  has  recently 
been  described  by  Reid.6  It  crosses  from  Lake  Tahoe  to  Washoe 
Lake.  The  general  age  of  the  Californian  placers  is  Neocene 
(Miocene  and  Pliocene)  ; c  that  of  the  Victorian  deep  gravels  is 
late  Pliocene. 

Range  in  Geological  Time  of  Placers. — A  consideration  of 
the  range  in  geological  time  of  auriferous  alluvial  deposits  at  once 
reveals  a  remarkable  feature,  viz.,  that  all  important  placers  are 
of  Tertiary  age,  and  that  of  these  the  majority  are  Recent,  Pliocene, 
or  Miocene  in  age.  Few  are  Eocene  and  fewer  still  Cretaceous. 
Older  than  Cretaceous  there  are  no  undoubted  examples  of  econo- 
mically valuable  deposits  of  placer  gold.  Possibly,  however,  an 
exception  to  this  statement  may  be  made  in  favour  of  the  Permo- 
Carboniferous  conglomerates  of  Tallawang  in  New  South  Wales. 
These  have  not  been  described  of  late  years  by  any  geologist,  but 
on  the  evidence  offered  many  years  ago  by  Wilkinson  there  seems 
little  doubt  of  the  alluvial  origin  of  the  contained  gold.  Similar 
auriferous  conglomerates  were  reported  also  many  years  ago,  by 
Daintree,  from  Peak  Downs,  Queensland.  Jurassic  auriferous 
conglomerates  have  been  described  by  Lindgren  d  from  the  Mariposa 
series  near  Mine  Hill,  Calaveras  County,  California,  and  Cretaceous 
(pre-Chico)  placers  by  Dunne  from  the  Klamath  range,  Oregon  ; 
but  exception  has  been  taken  by  Fairbanks/  to  the  alluvial  character 
of  the  gold,  which  is  considered  by  him  to  be  due  in  both  cases  to 
infiltration. 

There  are  at  least  two  great  goldfields  whose  features  of 
auriferous  deposition  must  be  considered  in  detail  before  this  question 

a  Wilkinson,  H.  L.,  Trans.  Inst.   Min.  Met.,  XVII,  1908,  p.  210. 

h  Min.  Sci.  Press,  Ap.  18,  1908,  p.  524. 

c  Lindgren,  Jour.  Geol.,  IV,  1896,  p.  881. 

d  Amer.  Jour.  Sci.,  XLVIII,  1894,  p.  275. 

e  12th  Ann.  Rep.  State  Mineral.,  Cal.,  1894,  p.  459. 

/Eng.  Min.  Jour.,  Ap.  27,  1895,  p.  389. 


WITWATERSRAND.  95 

may  be  dismissed,  and  even  before  any  validity  may  be  given 
to  the  above  statement,  restricting  the  range  in  geological  time  of 
placer  deposits.  Both  carry  gold  in  conglomerates  and  both 
are  of  Archaean  or  at  least  Pre-Cambrian  age.  The  contained  gold 
of  each  has  by  various  geologists  been  claimed  as  placer  gold,  and 
by  other  authorities  has  been  described  as  due  to  infiltration. 
They  are  the  famous  Witwatersrand  field  of  the  Transvaal,  and 
certain  occurrences  near  the  great  Homestake  mine  in  South 
Dakota. 

Witwatersrand. — The  great  economic  importance  of  the 
Witwatersrand  goldfield  has  directed  considerable  attention  towards 
this  remarkable  field,  and  several  hypotheses  have  from  time  to 
time  been  advanced  to  account  for  the  presence  of  gold  within  its 
"  banket  '  or  silica-cemented  conglomerate  beds.  Two  only  of 
these  hypotheses  have  stood  the  stress  of  time  and  agree  with 
accumulated  experience,  viz.,  the  placer  hypothesis  of  contem- 
poraneous deposition  of  gold  and  pebble,  and  the  infiltration 
hypothesis  of  introduction  of  gold  by  solutions  that  have  wandered 
through  the  gravels  long  subsequent  to  their  deposition.  The  former 
is  the  older  theory  and  has  been  excellently  set  forth  by  Becker, a 
and  later,  with  modifications,  by  Gregory. h  It  is  highly  characteristic 
of  the  long  discussion  that  has  been  carried  on  concerning  this 
subject  that  there  is  little  or  no  direct  evidence  in  support  of  either 
hypothesis,  and  that  the  case  for  each  rests  almost  entirely  on  the 
evidence  against  the  opposing  hypothesis. 

The  older  "  precipitation  hypothesis  ':  of  Schenck,  Stelzner, 
De  Launay,  and  others,  which  assumed  that  the  gold  had  been 
deposited  from  a  sea  containing  metallic  sulphides  and  gold  when 
the  conglomerates  were  still  at  the  surface,  has  been  revived  by 
Voit,c  but  in  a  form  so  modified  that  it  becomes  essentially  an 
infiltration  hypothesis,  differing  only  fro.m  the  one  generally  ad- 
vanced in  that  it  is  assumed  that  infiltration  took  place  at  the 
surface  before  the  conglomerates  were  depressed.  He  assumes 
that  solutions  loaded  with  metallic  sulphides  and  gold,  analogous 
apparently  to  those  of  hot  springs,  were  brought  in  great  quantity 
to  the  surface  at  the  periods  of  conglomerate  deposition  and  that 
the  metalliferous  content  found  the  requisite  precipitant  in  the 
great  amount  of  organic  matter  distributed  along  the  then  existing 
coast-line.  To  this  hypothesis  there  are  obvious  objections,  and 
these  arise  even  from  the  valuable  and  suggestive  evidence  offered 
in  the  paper  itself. 

a  18th  Ann.  Rep.  U.S.  Geol.  Survey,  Pt.  V,  1897,  p.  160. 
b  Trans.  Inst.  Min.  Met.,  XVI,  1907,  p.  1. 
c  Min.  Jour.,  Sept.  5,  1908,  p.  296. 


96  SECONDARY   AURIFEROUS    DEPOSITS. 

The  advocates  of  the  placer  theory  base  their  case  on  a  supposed 
general  resemblance  of  the  deposit  to  modern  placers.  The  resem- 
blance is,  however,  not  very  marked,  for  the  gold  is  exceedingly 
fine  in  grain,  and,  when  sufficiently  coarse  to  be  visible  to  the 
naked  eye,  is  often  angular.  Rounded  grains,  not  only  of  gold, 
but  also  of  pyrite,  do  occur,  and  are  regarded  as  evidence  in 
support  of  an  alluvial  origin. 

The  objections  to  the  placer  hypothesis  are  (a)  the  general 
fineness  in  grain  of  the  gold — a  fineness  that  in  modern  placers  is 
paralleled  only  in  beach  sands,  as  those  of  the  Snake  River  in 
Idaho,  and  of  the  west  coast  of  the  South  Island  of  New  Zealand  ; 
(6)  the  total  absence  of  those  nuggets  and  coarse  grains  that  are 
characteristic  features  of  all  modern  gravel  placers  ;  and  (c)  the 
absence  of  "black  sands"  (titanite,  magnetite,  and  garnet),  such 
as  are  found  also  in  all  modern  beach-sand  deposits  where  fine  gold 
occurs.  The  rounded  pyrite  pebbles  found  in  the  banket  are  amply 
explained  as  concretions  or  as  replacements  from  solution. 

The  infiltration  hypothesis  assumes  that  the  gold  was  deposited 
with  the  siliceous  cement  that  now  binds  together  so  strongly  the 
quartz-pebbles  of  the  banket.  In  its  support  is  adduced  (a)  the 
general  evenness  in  grade  of  the  gold  deposit  ;  (6)  the  fineness  of 
the  gold  ;  (c)  the  deposition  of  the  gold  on  pyrite  ;  (d)  the  general 
angularity  and  hackly  nature  of  the  gold  grains  ;  (e)  the  deposition 
of  gold  along  cracks  in  the  pebbles  of  the  banket  ;  and  (/)  the 
influence  occasionally  exercised  by  igneous  dykes  on  the  richness 
of  the  deposit."  As  an  argument  against  the  infiltration  theory  it 
has  been  advanced  that  the  overlying  and  underlying  quartzites 
should  also  have  been  impregnated  with  gold,  but  it  has  been 
shown &  that  the  quartzites  at  the  time  of  auriferous  impregnation 
may  have  been  comparatively  impermeable  rocks  and  that  the 
conglomerates  of  the  vertical  series  alone  were  sufficiently  porous 
to  permit  of  the  free  passage  of  wandering  solutions. 

The  validity  of  this  objection  is  rapidly  being  impaired  by 
gradually  accumulating  evidence  showing  that  while  gold  is  generally 
restricted  to  the  conglomerate  beds  it  nevertheless  occurs  in  economic 
quantities  in  normal  quartz -veins,  in  quartzites,  in  slaty  schists, 
and  in  certain  pyritous  bands  in  the  footwall  of  the  Main  Reef. 
These  are,  of  course,  not  proofs  of  an  infiltration  origin  for  the 
whole  of  the  gold  of  the  Witwatersrand,  but  they  at  the  least  show 
that  in  the  given  cases  the  gold  contained  is  not  alluvial.  A  normal 
white  quartz-vein  intercalated  in  the  footwall  quartzite  of  the  Main 

a  e.g.,  Worcester    Dyke,  cited    by    Hammond,  Trans.  Amer.  Inst.  M.E.,  XXXI, 
1901,  p.  844. 

b  Maclaren,  Trans.  Inst.  Min.  Met.,  XVII,  1908,  p.  50. 


WITWATERSRAND.  97 

Reef  has  been  worked  successfully  at  the  Rose  Deep  Mine  ;  at 
Kroomdraai  similar  gold-quartz  veins  occur  in  the  schistose  and 
pyritous  hanging-wall  of  the  Black  Reef,  a  much  higher  horizon 
than  that  of  the  Main  Reef.  Patches  of  quartzite  on  the  hanging- 
wall  of  the  Main  Reef  contain  appreciable  quantities  of  gold  ;  as 
also  do  certain  ferruginous  schists  in  the  footwall  of  the  Black  Reef. 
A  well-defined  dense  pyritic  quartzite  underlies  the  Main  Reef  and 
is  distant  from  it  about  90  feet.  This  band  has  been  opened  up  on 
many  mines  in  the  Central  and  Eastern  Rand.  Its  tenor  has  at 
times  been  high  ;  this  is  especially  the  case  when  the  band  is  very 
narrow,  and  in  some  cases  (Cinderella  Deep)  a  tenor  of  hundreds  of 
pennyweights  gold  per  ton  has  been  reached."  The  width  of 
the  pyritic  band  at  times  reaches  25  feet  ;  at  that  width  it  is  not, 
however,  workable  at  a  profit.  The  foregoing  facts  are  therefore 
ample  evidence  that  infiltration  of  gold  is  not  restricted  to  con- 
glomerate bands,  and  that  it  has  taken  place  elsewhere  when 
conditions  have  been  favourable. 

The  absence  of  "  verticals  '"  or  fissures  by  which  auriferous 
solutions  may  obviously  have  risen  to  the  conglomerate  beds  is 
urged  as  an  objection  to  impregnation.  The  absence,  however, 
of  an  undoubted  precipitant  of  gold  within  the  conglomerate  points 
rather  to  a  general  deposition  arising  from  physical  changes  in  the 
solution  than  to  one  from  chemical  reaction.  But  in  any  case, 
deposition,  either  of  silica  or  of  gold,  can  hardly  have  taken  place  in 
narrow  fissures  in  which  the  solutions  are  conceived  to  be  still  highly 
heated  and  to  be  travelling  with  comparative  rapidity.  More- 
over these  fissures,  representing  as  they  did  the  planes  of  structural 
weakness,  are  precisely  those  that  would  be  occupied  by  later 
extrusions  of  igneous  matter,  of  course  with  complete  obliteration 
of  the  original  characters  of  the  walls.  The  absence  of  well-defined 
ore-shoots  has  also  been  urged  against  the  infiltration  theory.6 
Ore-shoots  are,  however,  essentially  a  result  of  local  changes  in  the 
saturation  of  metalliferous  solutions  or  are  brought  about  by 
local  conditions  ;  they  must  necessarily  be  absent  where  conditions 
are  fairly  uniform  over  wide  areas.  Nevertheless  there  is  a  tendency 
in  depth  for  the  gold  of  the  banket-reefs  to  aggregate  to  shoots. 

With  the  data  at  present  at  hand,  the  gold  of  the  Witwatersrand 
banket  may  certainly  be  most  conveniently  considered  to  be  due  to 
infiltration.  It  is  possible,  though  there  is  no  evidence  whatever 
for  the  assumption,  that  the  banket  originally  contained  placer 
gold,  which  has  been  dissolved  and  redeposited  elsewhere  in  the 
conglomerate.     In  such  a  case,  however,  there  would  have  been,  in 

a  Voit,  loc.  cit.  sup. 
"  Gregory,  loc.  cit. 
G 


98  SECONDARY    AURIFEROUS    DEPOSITS. 

some  places  at  least,  local  aggregations  of  gold  to  nugget  size,  and 
it  has  already  been  shown  that  nuggets  or  masses  of  gold  are 
unknown,  at  least  at  depth,  where  there  has  been  no  possibility 
of  secondary  free-gold  enrichment.  In  any  case,  on  such  an 
assumption,  the  hypothesis  becomes  essentially  one  of  infiltration, 
when  it  is  scarcely  profitable  to  enquire  as  to  the  original  form  of 
the  gold  taken  into  solution. 

By  analogy,  moreover,  with  other  auriferous  occurrences  in  the 
Transvaal,  and  especially  with  those  of  the  Lydenburg  district, 
the  Witwatersrand  gold  may  reasonably  be  referred  to  the  same 
agents  that  have  obviously  been  effective  in  the  latter  cases,  viz.,  the 
diabasic  masses  (or  rather  their  advanced,  contemporaneous,  or 
consequent,  heated  solutions)  that  intrude  through  the  conglomerate 
"reefs  "  of  the  Rand,  or  overlie,  as  sills,  the  flat-lying  reefs  of  the 
Pilgrim's  Rest  field. 

South  Dakota — The  auriferous  Cambrian  conglomerates  of 
the  neighbourhood  of  the  great  Homestake  Mine  in  South  Dakota 
have  long  been  considered"  to  owe  their  gold  to  alluvial  deposition. 
There  are,  however,  in  the  immediate  vicinity  widespread  im- 
pregnations of  secondary  silica  that  carry  gold.  These  are  nearly 
always  connected  with  the  so-called  "  verticals,"  or  vertical  fissures 
that  pass  down  into  the  underlying  Algonkian  schists,  and  that 
have  obviously  served  as  channels  for  the  uprising  metalliferous 
solutions.  Emmons, l'  who  has  conducted  the  most  recent  geological 
examination  of  this  area,  and  who  is  pre-eminently  well  qualified 
to  judge,  has  concluded  from  the  waterworn  character  of  some  of 
the  gold  and  from  its  concentration  near  bed-rock,  that  some  at 
least  of  the  gold  of  the  conglomerate  is  of  placer  origin,  but  that 
the  enrichment  of  the  deposit  to  one  of  economic  value  is  due 
entirely  to  the  work  of  secondary  auriferous  solutions,  which  are 
also  responsible  for  the  pyrite  with  which  the  auriferous  portions 
of  the  conglomerate  are  invariably  associated.  The  pyrite  is  often 
found  occupying  fissures  and  cavities  in  the  pebbles.  Clear  evidence 
of  local  secondary  enrichment  is  afforded  by  the  presence  of  films 
of  gold  in  the  laminations  of  the  schist  and  in  crevices  from  3  to  10 
feet  below  the  base  of  the  conglomerate. 

Nullagine,  Western  Australia. — The  Nullagine  auriferous 
conglomerates  of  the  Pilbara  field,  Western  Australia,  closely 
resemble  those  of  the  Witwatersrand,  but  in  addition  to  the  gold 
contained  in  the  siliceous  matrix  between  the  pebbles,  gold  is 
also  found  in  thin  white  quartz-veins  that  are  parallel  to  the  bedding 


a  Devereux,  Trans.  Amer.   Inst.   M.E.,  X,  1889,  p.  iGo. 

h  Emmons,  S.  F.,  Prof.  Papers  U.S.  Geol.  Surv.,  Xo.  26,  1904,  p.  99. 


ANCIENT    GRAVELS.  99 

planes.  The  veins  are  much  richer  in  gold  than  the  siliceous  cement, 
and  there  is  thus  evidence  to  support  the  view  that  the  gold  of  the 
latter  is  due  to  infiltration. 

It  is  noteworthy  that  these  ancient  Cambrian  or  Pre-Cambrian 
conglomerates  are  all  highly  silicified  and  pyritised.  They  all,  it 
would  appear,  owe  their  gold  to  infiltration  rather  than  to  con- 
temporaneous deposition.  The  question  therefore  arises  as  to  the 
reason  for  the  restriction  of  undoubted  placer  deposits  to  the 
Tertiary  period.  It  is  not  conceivable  that  conditions  of  denudation 
different  to  those  in  existence  at  the  present  day  prevailed  in  the 
Palaeozoic  and  Mesozoic  periods.  The  strata  of  these  periods 
contain  numerous  conglomerate  beds  that  are  situated  in  the 
vicinity  of  older  auriferous  regions.  Conglomerates  of  Gondwana 
(Permo-Triassic)  age  are  largely  developed  in  India,  Eastern  Aus- 
tralia, South  Africa,  and  the  Argentine.  They  are,  it  is  true,  for 
the  most  part  of  glacial  origin,  but  such  an  origin  does  not  preclude 
the  possibility  of  gold  deposits,  for  the  rewash  of  recently 
deposited  glacial  matter  has  yielded  auriferous  deposits  of  economic 
value.  It  is  therefore  probable  that  wherever  Palaeozoic  or 
Mesozoic  conglomerates  were  formed  in  the  degradation  of  an 
auriferous  area,  they  contained  alluvial  gold  distributed  in  >k  leads  >! 
precisely  analogous  to  those  already  described  from  Victoria  and 
California.  It  is  believed  that  these  ancient  gravels  have  all,  in 
the  course  of  orogenic  movements,  been  depressed  below  the  ground- 
water level,  and  into  the  region  of  the  alkaline  deep-seated  waters. 
Here  the  gold  has  been  dissolved  and  removed,  probably  to  be  re- 
deposited  as  free  gold  in  clean  quartz  in  adjacent  rocks,  or  possibly  to 
pass  to  the  sea,  not  again  to  be  concentrated  in  economic  degree 
for  long  geological  ages.  Should,  however,  the  gold  grains,  prior  to 
the  introduction  of  a  solvent,  be  enclosed  in  silica  (acid  siliceous 
solutions  being  assumed  to  have  no  effect  on  gold),  the  placer-gold 
may  be  preserved  for  an  indefinite  time.  Hence  we  have  the 
original  gold  of  the  Homestake  Cambrian  occurrences,  and  possibly 
also  the  faintly  auriferous  conglomerates  of  France  and  England. 
But  such  a  preservation  would  appear  to  be  exceptional,  and 
ancient  conglomerates  are  on  the  whole  devoid  of  gold.  It  is 
further  noteworthy  that  rich  ancient  gravels,  as  those  of  California 
and  Victoria,  occupy  regions  that  have  not  suffered  a  notable 
depression.  Admitting  the  foregoing  speculation  we  have  therefore 
a  complete  cycle  of  auriferous  transference,  from  deep-seated  vein 
to  surface  placer,  and  from  depressed  placer  to  vein. 


100 


SOURCE  AND  TRANSPORT  OF  GOLD. 


Source  of  Gold. — In  the  investigation  of  auriferous  deposits 
no  feature  stands  out  in  greater  relief  than  the  constant  association 
of  the  primary  goldfields  with  igneous  rocks,  and  it  therefore  becomes 
necessary  to  examine  the  evidence  available  for  the  occurrence  of 
gold  as  an  original  constituent  of  an  igneous  magma.  As  a  rule  the 
evidence  offered  is  valueless,  from  the  impossibility  of  establishing 
definite  criteria  of  authigenesis  for  gold  and  rock,  and  in  many 
instances  that  have  been  advanced  the  gold  with  its  associated 
pyrite  has  certainly  been  subsequently  introduced  into  the  cooling 
or  cooled  igneous  rock  by  percolating  solutions.  There  are,  how- 
ever, certain  cases  that  do  not  obviously  fall  within  the  above 
category.  They  have  been  described  by  Merrill/'  Schultze,6 
M6ricke,c  Blake,^  Helmhacker,e  Jacquet,/  Scheibe,?  Brock,^ 
Catharinet,'  and  others.  With  the  exception  of  those  noted 
by  Helmhacker  from  diorite  and  serpentine  rocks  in  the 
Urals,  and  by  Scheibe  in  an  olivine  rock  from  Damara 
Land,  South  Africa,  all  the  foregoing  are  from  acid  rocks,  that 
described  by  Merrill  being  in  a  normal  biotite-granite  from  Sonora, 
Mexico,  while  Moricke's  specimens  showed  native  gold  in  pearlstone 
(obsidian)  from  Guanaco,  Chile,  as  skeleton  crystals  in  the  glass 
and  as  inclusions  in  perfectly  fresh  plagioclase  and  sanidine  crystals 
and  in  spherulites.  Jacquet  records  the  occurrence  of  free  gold 
in  the  microcline  of  a  quartz-microcline  rock  impregnated  with 
haematite.  Brock  reports  gold  from  porphyries  in  British  Columbia  ; 
Catharinet's  examples  are  also  from  the  same  region,  but  in  peg- 
matites. 

Two  instances  at  least  of  the  occurrence  of  gold  in  economic 
quantities  within  acidic  dyke  rocks  are  known,  but  in  both  cases  it 
may  be  clearly  shown  that  the  gold  is  of  later  origin.  Both  are 
fully  described  elsewhere  in  this  volume  and  need  only  be  mentioned 
here.     The  first  is  that  of  Berezovsk,  Ural  Mountains,  where  the 

a  Amer.  Jour.  Sci.,  I,  1896,  p.  309. 

b  H.  Kunz,  "  Chile,"  1890,  p.  78. 

cTscherm.  Min.   Petrog.   Mittheil,  XII,   1891,  p.   195. 

d  Trans.  Amer.  Inst.  M.E.,  XXVI,  1896,  p.  290. 

e  Oesterr.  Zeit.  fur  Berg-  nnd  Hiitt.,  XXVIII,  1880,  p.  97. 

/Mem.  Geol.  Surv.  N.S.W.,  No.  5,  1894. 

9  Zeit.  Deutsch.  Geol.  Gesell.,  XL,  1888,  p.  611. 

hEng.  Min.  Jour.,  1904,  p.  511. 

*  Eng.  Min.  Jour.,  1905,  p.  127. 


GOLD    IN    IGNEOUS    ROCKS. 


101 


gold  occurs  in  thin  veinlets  in  microgranite  (beresite),  and  the 
second  is  that  of  Omai  in  British  Guiana,  where,  however,  the  gold 
occurs  not  solely  in  thin  stringers  of  quartz  in  an  aplite  dyke,  but 
also  scattered  through  the  mass  of  the  aplite.  The  dyke  is  decom- 
posed to  great  depth,  but  where  fresh  contains  notable  quantities 
of  auriferous  pyrite,  the  decomposition  of  which  has  furnished  the 
free  gold  of  the  upper  zones. 

Despite  the  foregoing,  however,  the  occurrence  of  free  gold  as 
an  original  constituent  of  unaltered   igneous  magmas  cannot   be 


Fig.  69.     Thin  Section  showing  Free  Gold  in  Diorite  from  Mashonalasd  (Spttrr). 
X    25  ;    /.  felspar  ;    q.  quartz  ;    e.  epidote  ;    k.  hornblende  ;    m.  magnetite  ;  g.  gold. 

considered  fully  proven.  The  gold  may  have  been  caught  up  from 
veins  or  sediments  by  an  intruding  magma,  or  the  granitic  rock 
may  itself  be  metamorphic  and  its  gold  derived  from  veins  enclosed 
within  the  original  rock.  That  apparently  igneous  acidic  crystalline 
rocks  may,  in  exceptional  cases,  be  really  of  metamorphic  origin, 
the  present  writer,  reasoning  from  analogy  with  certain  diorites 
of  metamorphic  origin/'  fully  believes.  Further,  the  presence  of 
orthoclase  and  albite  in  many  normal  auriferous  quartz-veins 
(Bendigo,  California,  Cripple  Creek,  &c.)  may  suggest  an  explanation 


a  Maclaren,  Rec.  Geol.  Surv.  India,  XXXIV,  1908,  p.  112. 


102  SOURCE    OF   GOLD. 

for  the  free  gold  in  the  quart z-microcline  rock  of  Jacquet,a  viz., 
that  the  rock  matrix  is  essentially  an  aqueous  deposit.  It  is 
interesting  to  note  that  Liversidge b  records  the  presence  of  gold 
in  certain  European  and  Australian  meteorites  (siderolites). 

The  auriferous  tonalite-  or  quartz-diorite-gneiss  of  the  Ayrshire 
mine,  Lomagunda,  Rhodesia,  has  been  described  by  J.  E.  Spurr.c 
The  rock  lies  between  hornblende  and  chloritic  schists,  and  is 
only  100  feet  distant  from  a  granite  mass.  It  was  at  first  considered 
to  be  a  true  diorite,  but  is  a  fresh  fine-grained  diorite-gneiss,  com- 
posed chiefly  of  felspar  and  grey  hornblende.  Quartz,  biotite, 
magnetite,  and  epidote  also  occur.  The  gold  is  most  closely 
connected  with  the  hornblende  and  magnetite,  but  also  occurs 
rarely  as  inclusions  in  the  quartz  and  felspar.  The  rock  follows  a 
fairly  distinct  bedding,  and  the  gold  may,  on  the  whole,  be  reasonably 
regarded  as  derivative  from  veinlets  in  an  older,  presumably  igneous 
rock  now  highly  metamorphosed.  Somewhat  similar  biotite-gneisses 
containing  pyrites  are  recorded  by  Lacroix^  from  the  Mundraty 
River,   Madagascar. 

The  close  connection  between  igneous  rocks  and  auriferous 
regions  may  have  been  brought  about  in  either  or  both  of  two 
ways  :  The  gold  may  have  been  brought  near  the  surface 
and  within  the  reach  of  meteoric  waters  by  inclusion  within  an 
ascending  magma.  Considerable  weight  was  given  to  this  view 
by  the  work  of  Becker  and  others  on  the  country  of  the  Comstock 
Lode,  all  tending  towards  the  conclusion  that  the  gold  resided  in 
the  ferro-magnesian  silicates.  Don,  on  the  contrary,  has  shown, 
for  the  igneous  districts  examined  by  him,  that  gold  does  not 
necessarily  reside  in  the  ferro-magnesian  silicates.  He  has  further 
shown  that,  for  the  given  districts,  the  amount  of  gold  present  in 
the  country  rock  is,  as  a  general  rule,  directly  proportional  to  the 
amount  of  pyrite  present,  and  also  that  the  amount  of  pyrite 
decreases  inversely  as  the  distance  from  the  vein- fissure.  Since 
the  pyrite  may  be  considered  to  be  entirely  secondary  and  to 
have  been  introduced  by  percolating  waters,  we  are  thus  brought 
to  the  second  view,  viz.,  that  auriferous  solutions  have  been  intro- 
duced by  uprising  waters  that  have  a  connection  with  igneous 
masses.  Until  detailed  and  extended  analyses  of  fresh  igneous 
rock  and  of  igneous  emanations  have  been  made,  the  problem  will 
remain  a  matter  for  pure  speculation.  In  the  absence  of  definite 
data,  it  is  here  assumed  that  the  auriferous  content  of  many  waters, 

a  Loc.  cit.  sup. 

*>  Jour.  Roy.  Soc.  N.S.W.,  XXVI,  1902,  p.  xxiv. 

r  Eng.  Min.  Jour..  Oct.  3,  1903. 

d  C.  R.  Acad.Sci.  Paris,  CXXXII,   1901,  pp.   180-182. 


SOURCE    OF   GOLD.  103 

and  especially  of  those  which  are  set  in  circulation  by  intrusive 
igneous  rocks,  as  by  the  Pre-Cambrian  diabases,  is  derived  from 
emanations  from  intrusive  magmas,  the  emanations  being  finally 
dissolved  in  percolating  waters  and  by  them  carried  into  vein- 
fissures.  From  whatever  side  the  question  is  approached,  primary 
auriferous  deposits  may  be  regarded  as  phenomena  dependent 
on  the  extrusion  of  igneous  magmas,  and  further  as  having  an  origin 
indissolubly  bound  up  with  that  of  metalliferous  sulphides  or  of 
the  chemically  related  tellurides.  Work  throwing  light  on  the 
origin  of  pyrite  is,  therefore,  to  be  welcomed  as  assisting  enquiry 
into  the  genetic  relations  of  gold. 

Transport  of  Gold. — The  gold  in  vein  waters  may  most 
reasonably  be  regarded  as  ionized  and  balanced  either  as  auro- 
silicanion,  as  thio-auranion,  or  as  telluro-auranion ;  in  the  first 
case  the  deposition  products  are  silica  and  free  gold  ;  in  the  second 
case,  free  gold  and  sulphides,  or  possibly  sulphides  (including 
gold-sulphide)  alone  ;  and  in  the  final  case,  gold-tellurides.  The 
first  combination  is  considered  by  the  writer  to  be  the  probable 
form  in  all  those  veins  in  which  free  gold  is  found  studding  clean 
quartz.  Even  in  many  pyritous  veins,  deposition  of  pyrite,  quartz, 
and  gold  has  been  contemporaneous.  In  such  cases  the  gold 
would  appear  to  have  been  held  by  both  the  first-mentioned  ions 
and  to  have  been  freed  on  deposition. 

Since  gold  has  never  been  definitely  isolated  from  or  recognised 
in  underground  waters  all  speculations  on  the  manner  in  which 
it  is  dissolved  and  transported  must  necessarily  be  tentative. 
There  are,  however,  several  established  solvents  of  gold  that  may 
well  play  important  parts  in  the  transport  of  gold  in  nature.  Of 
these  the  chief,  in  the  deeper  zones  at  least,  are  the  alkaline  sulphides, 
if  any  value  is  to  be  placed  on  the  widespread  association  of  base 
sulphide  and  gold.  The  same  importance  cannot,  for  various 
reasons,  be  given  to  the  solvent  action  of  alkaline  silicates,  and  it 
has  elsewhere  been  shown  that  colloidal  gold  solutions,  the  third  form 
in  which  gold  may  be  transported  underground,  requiring,  as  they 
do,  pure  water  and  neutral  conditions,  are  of  doubtful  occurrence. 
In  this  connection  the  experiments  of  Doelter"  are  instructive.  He 
found  that  gold  was  somewhat  readily  soluble  in  an  8  per  cent,  solution 
of  sodium  carbonate  with  sodium  silicate  and  an  excess  of  carbonic 
acid.  Transport  of  gold  as  an  alkaline  auro-silicate  may  thus 
be  admitted.  It  has  been  seen  that  tellurides  of  gold  are 
of  common  occurrence,  and  from  the  general  chemical  analogy 
between  sulphides  and  tellurides,  the  latter  may  be  considered 
to  have  been  also  transported  in  alkaline  solution.  In  regions 
affected  by  meteoric  waters  possible  natural  solvents  appear  to 

"Tscherm.  Min.  Mittheil.,  XI,  1890,  p.  329. 


104  TRANSPORT    OF    GOLD. 

be  fairly  numerous.  Stokes a  shows  that  gold  is  readily  soluble, 
at  a  temperature  of  200°  C,  in  solutions  of  ferric  chloride  and  cupric 
chloride,  the  gold  forming  a  chloride.  The  percentage  of  gold 
dissolved  increases  with  the  temperature  and  with  the  concentration 
of  the  solution.  Ferric  sulphate  also  dissolves  gold,  but  only  in 
the  presence  of  a  chloride.  That,  however,  the  process  of  solution 
by  ferric  salts  is  not  a  simple  reaction  at  normal  temperatures 
and  pressures  is  shown  by  the  experiments  of  Don/J  who  failed 
even  with  strong  solutions  (from  1  to  20  grains  per  litre)  to  dissolve 
either  metallic  gold  or  auriferous  sulphides.  The  ready  solubility 
of  gold  in  alkaline  sulphides  has  been  demonstrated  by  various 
chemists.0  Skey  further  thought  that  gold  was  soluble  in  hydrogen 
sulphide,  and  it  is  probable  that  this  reagent,  though  perhaps 
rather  indirectly,  in  alkaline  combination,  than  directly,  does  exercise 
a  notable  effect.  All  these  reagents  occur  in  natural  waters,  and 
that  some  solvent  action  does  take  place  is  indicated  by  the  presence 
of  gold  in  the  sinter  of  sulphurous  springs  in  Nevada  and  New 
Zealand.^  As  long  ago  as  1877,  Liversidgee  found  gold  in  recently- 
formed  pyrite  that  had  been  deposited  on  twigs  in  hot  springs  near 
Lake  Taupo,  New  Zealand. 

Waters  containing  free  chlorine,  or  compounds  that  may 
furnish  free  chlorine,  are  always  competent  to  dissolve  gold.  The 
not  improbable  combination  in  nature  of  an  acid,  manganese 
di-oxide,  and  an  alkaline  chloride,  would  therefore  fulfil  the  con- 
ditions requisite  for  the  solution  of  gold./ 

The  existence  of  gold  in  sea-water  had  long  been  suspected 
before  its  occurrence  was  qualitatively  proved  by  Sonstadt.^  whose 
further  quantitative  determination  showed  results  roughly  estimated 
at  less  than  1  grain  gold  per  ton.  Quantitative  determinations  have 
also  been  made  by  Liversidge,  Don,  and  others,  showing  results 
always  less  than  1  grain  per  ton.  The  presence  of  gold  in  the  waters 
offthe  ocean  being  thus  established,  it  has  been  suggested  that  the 
gold  of  fissure-veins  in  sedimentary  rocks  has  been  derived  from 
sea-water  carried  down  during  the  course  of  deposition  of  the 
sediments,  and  from  them  has  been  removed  into  the  fissures  by 

a  Econ.  Geol.,  I,  1906,  p.  650. 

b  Trans.  Am.  Inst.  M.E.,  XXVII,  1898,  p.  598. 

c  Skey,  Trans.  N.Z.  Inst,,  III,  1870,  p.  216  ;  Egleston,  Trans.  Am.  Inst.  M.E., 
IX,r  1880-1,  p.  639  ;  Becker,  Am.  Jonr.  Sci.,  XXXIII,  1887,  p.  207  ;  Liversidge,  Proc. 
Roy!  Soc.  N.S.W.,  XXVII,  1893,  p.  303. 

d  Becker,  Mon.  U.S.  Geol.  Surv.,  XIII,  1888,  p.  344  ;  Maclaren,  Geol.  Mag.,  1906, 
p.  511. 

e  Jour.  Roy.  Soc.  X.S.W.,  XI,  1877,  p.  262. 

/Don,  Trans.  Am.  Inst,  M.E.,  XXVII.  1897.  p.  564;   Pearce.  ibid..  XXII,   1893, 
p.  739;    Rickard,  T.  A.,  ibid.,  XXVI,  1896,  p.  978. 
tfChem.  Xews,  XXV,  1872,  pp.  196,  231,  241. 


/I  .  *\   1    T  ~> 


TRANSPORT    OF    GOLD.  105 

lateral  secretion.  There  is  little  to  be  said  for  this  assumption. 
On  the  other  hand,  it  is  reasonable  to  assume  that  a  proportion 
of  the  steam  ejected  from  maritime  volcanoes  has  been  derived 
from  the  adjacent  seas.  In  such  cases  the  contained  gold  is  deposited 
within  the  rock,  either  in  fissures  or  vents,  or  in  the  rock-mass  itself. 
Notable  quantities  of  gold  may  thus  have  been  introduced  into 
the  solid  portion  of  the  outer  crust. 

Lenher's  experiments,"  showing  that  gold  is  soluble  in  sulphuric, 
phosphoric,  and  other  acids  if  a  compound,  as  manganese  di-oxide, 
capable  of  liberating  oxygen  be  present,  are  of  great  importance  as 
affecting  the  solution  of  gold  in  the  upper  zones  of  veins  that  lie 
within  the  reach  of  oxidising  waters.  Van  Hise  has  clearly  shown 
that  ferric  and  other  -ic  salts  are  abundantly  produced  in  the  zone 
of  weathering  by  the  action  of  descending  solutions  on  the  minerals 
of  the  deeper  zone,  as  pyrite.  Their  solvent  action  becomes,  there- 
fore, of  considerable  importance  when  considering,  as  will  later 
be  done  in  detail,  the  problems  of  secondary  enrichment. 

Epitomising  briefly  the  course  pursued  by  gold  from  its 
hypothetical  magmatic  host,  it  may  be  said  that  in  the  deeper 
zones  transport  upwards  is  effected  by  alkaline  sulphides  or  tellurides 
and  alkaline  silicates  ;  in  the  vadose  zone  or  zone  of  weathering, 
as  the  surface  of  the  land  is  gradually  lowered  by  erosion,  the  free 
gold,  gold-telluride,  or  possible  gold-sulphide  of  the  uppermost 
portions  of  the  deep  zone  is  attacked  by  acid  chloride  waters  and 
by  them  is  carried  either  upward  to  or  near  the  actual  outcrop, 
depositing  their  content  as  free  gold,  or  downward  to  the  permanent 
ground  water-level,  where  the  gold  is  deposited  with  base  sulphides. 

Dispersion  of  Gold  in  Nature- — The  dispersion  of  gold  is 
effected  both  by  mechanical  and  by  chemical  agencies.  Water, 
either  liquid  or  solid,  acting  at  the  earth's  surface  is  the  chief  of 
the  former.  In  rapidly-flowing  streams  with  hard  rock  bottoms 
with  or  without  pot  holes,  coarse  gold  is  in  the  course  of  time 
triturated  to  fine  flaky  powder,  in  which  condition  it  is  transported 
with  ease  even  at  or  near  the  surface  of  the  stream  waters,  and 
comes  to  rest  only  with  the  finest  of  sediments.  In  certain  rivers 
the  fine  "  float  "  gold  is  so  abundant  that  its  capture  by  "  fly- 
catching  '  tables  has  proved  a  profitable  avocation.  Such  gold 
may  pass  to  the  sea  to  be  deposited  in  fine  muds,  or  on  the  sand  or 
gravel  beaches  along  which  it  is  swept  by  tide  or  current.  In  either 
case  it  is  almost  certain  that  the  ultimate  fate  of  the  gold  is 
solution  in  sea-water. 

f/ Jour.  Amer.  Chem.  Soc,  XXVI,  1904,  p.  550. 


106  DISPERSION    OF   GOLD. 

In  tropical  regions,  subject  to  violent  and  short-lived  floods, 
rivers  and  streams  are,  in  general,  agents  of  dispersion  rather  than 
of  concentration  of  gold.  Throughout  India,  a  country  typical 
of  these  conditions,  from  the  Himalayas  to  Cape  Comorin,  small 
quantities  of  gold  (rarely  more  than  -?>-grain  gold  per  ton)  may  be 
obtained  wherever  coarse  gravels  are  found  ;  yet  in  all  that  extensive 
area  no  placer  aggregations  of  economic  value  are  found  or  are 
likely  to  be  found. 

In  high  latitudes  or  at  high  altitudes  glaciers  exercise  a  minor 
dispersive  effect.  They  wear  down  the  outcrops  of  lodes  that  have 
possibly  undergone  "  secondary  enrichment  "  prior  to  the  period 
of  glaciation,  and  so  scatter  fragments  of  auriferous  quartz  through 
a  great  mass  of  morainic  matter. 

Coastal  erosion  attacking  an  exposed  "  deep  lead  "  or  a  gold- 
quartz  vein,  may  destroy  the  aggregation  of  the  gold  and  disperse 
it  widely  through  sands.  Examples  of  the  latter  case  are  not 
uncommon. 

No  evidence  is  at  present  available  indicating  a  natural  pre- 
cipitation of  gold  from  sea-water,  and  the  sea  must,  on  the  whole, 
and  so  far  as  chemical  action  is  concerned,  be  regarded  as  an  agent 
solely  of  dispersion. 

Underground  waters,  by  virtue  of  their  heat  or  of  their  contained 
salts,  may  act  as  a  dispersing  agent.  It  has  been  shown  that  alkaline 
sulphides  in  the  deep  regions  and  -ic  salts  in  the  vadose  zone  are 
ready  solvents  of  gold,  and  it  is  quite  conceivable  that  re-deposition 
of  gold  from  these  and  other  wandering  solvents  may  result  in  a 
more  widely-distributed  deposit  than  the  original  from  which 
the  gold  was  derived. 

It  has  already  been  remarked  as  a  noteworthy  fact  that,  so  far 
as  our  knowledge  goes,  extensive  auriferous  alluvial  deposits  are 
confined  to  Tertiary  strata  that  have  not  yet  been  depressed  to 
any  considerable  depth  beneath  the  earth's  surface.  It  cannot  be 
conceived  that  the  agencies  of  denudation,  erosion,  and  deposition 
during  the  Palaeozoic  and  Mesozoic  periods  differed  materially 
either  in  character  or  in  degree  from  those  now  in  operation.  The 
conclusions  arrived  at  therefore  have  been  that  auriferous  alluvial 
gravels  ivere  deposited,  but  that  from  the  necessarily  porous  nature  of 
the  gravels  or  conglomerates,  such  beds  when  depressed  below 
ground-water  level  afforded  ideal  conditions  for  the  leaching  action 
of  deep-seated  solutions,  which  have  carried  the  gold  to  be  deposited 
elsewhere,  possibly  in  a  notable  state  of  aggregation  in  fissures, 
possibly  widely  diffused  in  percolating  waters. 

Another  method  of  dispersion  of  gold  is  finally  admitted.  It  is 
purely  hypothetical,  but  yet  is  sufficiently  reasonable.   It  is  assumed 


DISTRIBUTION    OF    GOLD. 


107 


that  igneous  magmas  may  eat  their  way  toward  the  earth's  surface. 
In  such  cases  any  gold  formerly  contained  and  concentrated  in 
the  rock  so  absorbed  is  in  the  course  of  time  distributed  throughout 
the  magma. 

The  assays  of  Wagoner, a  on  rocks  far  removed  from  known 
metalliferous  deposits,  show  how  widely  spread  are  gold  and  silver 
at  the  outer  surface  of  the  earth's  crust.  His  researches  appear 
to  have  been  conducted  with  the  extreme  care  necessary  in  these 
assays  where  litharge,  which  is  apt  to  contain  unsuspected  quan- 
tities of  gold,  is  used.  The  figures  given  below  are  in  milligrams 
per  metric  ton  ;    the  rocks  assayed  are  mainly  Calif ornian. 


Granite 

Do 

Do 

Syenite,  Nevada  . 
Granite,  Nevada  . 
Sandstone     


An. 

Ag. 

104 

7,660 

137 

1,220 

115 

940 

720 

15,430 

1,130 

5,590 

39 

540 

Sandstone     

Do. 

Basalt    

Diabase 

Marble 

Marble,  Carrara 


Au. 


24 
21 

26 

76 

5 

8-63 


Ag. 


450 
320 
547 
7,440 
212 
201 


It  is  probable  that  the  wide  distribution  of  gold  above  indicated 
is  closely  connected  with  that  of  pyrite. 

/ 
2~ 


"Trans.  Amer.  Inst.  M.E.,  XXXI,  1901,  p.  808. 


108 


DEPOSITION    AND    CONCENTRATION    OF 

GOLD. 


Precipitants  of  Gold. — In  whatever  form  and  by  whatever 
means  gold  is  transported,  it  is  deposited  either  as  free  gold  or  as 
a  telluride  of  gold.  It  is,  as  has  already  been  indicated,  at  present 
impossible  to  say  whether  deposition  as  a  sulphide  also  takes  place. 
The  amount  of  free  energy  shown  by  the  complex  ions  of  gold  indi- 
cates ready  reduction  of  the  element,  and  the  precipitants  of  gold 
are  consequently  numerous.  They  may  be  gaseous,  as  sulphuretted 
hydrogen,  liquid,  as  a  solution  of  ferrous  sulphate,  or  solid,  as 
numerous  sulphides  and  as  gold  itself  ;  again,  a  physical  modification 
of  auriferous  solutions  may  induce  precipitation.  Of  the  active 
physical  factors,  decrease  of  temperature  and  decrease  of  pressure 
are  the  most  potent  ;  minor  physical  agents  are  those  involved 
in  a  modification  of  the  degree  of  dilution  of  an  auriferous  solution, 
and  in  the  change  from  the  colloidal  to  the  crystalline  state. 

The  chief  of  the  chemical  agents  of  precipitation  is  probably  the 
base-metal  sulphide  group.  These  act  mainly  below  the  ground-water 
level,  and  there  is  very  often  a  fairly  definite  relation  between  the 
occurrence  of  gold  and  of  the  base  sulphide,  which  is  generally 
pyrite  or  chalcopyrite.  Thus  Dona  shows  for  the  Victorian  rocks 
that  where  sulphides  are  abundant  the  total  amount  of  gold  is 
likely  to  be  great,  and  that  when  a  small  quantity  of  pyrite  is 
present,  gold  also  is  lacking.  The  same  relations  also  hold  for  many 
Calif ornian  gold-quartz  veins. b  In  these  cases  it  is  believed  that 
the  gold  has  been  carried  in  solution  as  an  alkaline  sulphide,  and 
the  same  cause  that  induced  the  precipitation  of  the  base  sulphide 
has  induced  that  of  the  free  gold.  Skey,c  Liversidge,^  and  others, 
have  shown  that  nearly  all  natural  base  metallic  sulphides  will 
precipitate  gold,  at  least,  from  auric  chloride  solutions.  This 
reaction  suggests  a  prior  deposition  in  nature  of  the  base  sulphides, 
which  then  act  as  a  precipitant  for  gold.  According  to  Skey,  one 
part  of  pyrite  will  precipitate  more  than  eight  parts  of  gold.  Never- 
theless, it  must  be  pointed  out  that  while  laboratory  experiments 
have  shown  that  deposition  of  gold  from  solution  in  these  cases  takes 
place  as  a  shining  metallic  film  on  the  pyrite,  no  gilded  pyrite  or 
other  sulphide   is  known  in  nature. 

«  Trans.  Araer.  Inst.  M.E.,  XXVII,  1898,  p.  567. 

&Lindgren,  17th  Ann.  Rep.  U.S.  Geol.  Surv.,  II,  1896,  p.   182. 

c  Trans.  N.Z.  Inst.,  Ill,  1870,  p.  225. 

^Proc.  Roy.  Soc.  N.S.W.,  XXVII,  1893,  p.  303. 


TELLURIDES    OF    GOLD. 


109 


The  recent  work  of  Lenher  and  Hall,"  on  the  reducing  power 
of  tellurides  of  gold,  is  of  great  interest  when  considering  the  dis- 
tribution of  free  gold  in  gold-telluride  veins  and  ore-channels. 
They  found  that  the  natural  tellurides  of  gold,  silver,  and  mercury 
(calaverite.  krennerite,  sylvanite,  nagyagite,  hessite,  and  coloradoite) 
readily  reduce  metallic  gold  from  its  solutions.  While  most  of  the 
free  gold  of  Kalgoorlie,  for  example,  is  undoubtedly  derived  from 
the  decomposition  of  the  tellurides  by  vadose  waters,  there  are 
occasional  occurrences  of  free  gold  at  considerable  depths  which 
are  rather  to  be  attributed  to  the  reducing  power  of  tellurides  on 


Figs.  70  add  71.     Showing  Relations  of  Gold,  Telluride-ore,  and  Quartz  at  (a)  Goldfield, 
Nevada,  and  (b)  Kalooorlie,  Western  Australia  (Skarwood). 

ascending  solutions  containing  gold.  It  is  conceivable  that  this  action 
may  be  of  considerable  economic  importance. 

Selenium  and  selenides  precipitate  gold  in  the  same  manner 
as  tellurides  ;  in  both  cases  time  is  an  important  factor  in  obtaining 
complete  precipitation. 

In  the  zone  of  oxidation  -ous  salts  and  oxides  are  potent  pre- 
cipitating agents.  The  most  notable  of  these  are  ferrous  sulphate 
and  ferrous  chloride.  Stokes  b  claims  that  the  chemical  action  varies 
with  the  temperature,  and  that  the  reactions  are,  as  shown  below, 
reversible. 

Au  CI,  +  3  Fe  Cl2  <^ZT>  Au  +  3  Fe  Cl3. 

With  a  falling  temperature  the  result  is  shown  on  the  right- 
hand  side  of  the  equation  ;  with  a  rising  temperature  the  tendency 
to  revert  to  the  salts  shown  on  the  left-hand  side  is  followed. 


« Jour.  Am.  Chem.  Soc,  XXIV,  1902,  p.  918. 
6Econ.  Geo!.,  I,  1906,  p.  650. 


110  DEPOSITION    OF   GOLD. 

Ferrous  sulphate  is  often  abundant  in  the  waters  of  the  oxidised 
zone.  The  old  disused  workings  of  the  Cambria  mine,  Thames 
Goldfield,  New  Zealand,  at  times  contain  stalactites  of  ferrous 
sulphate  (green  vitriol)  3  feet  in  length.  It  is  to  be  noted  that 
according  to  Moissana  exceedingly  dilute  solutions  of  gold  in 
complex  media  are  not  precipitable  by  ferrous  salts  or  by  sulphurous 
acid. 

A  most  important  reducing  agent  is  organic  matter.  Its 
association  with  gold  has  long  been  noted,  and  is  described  in  detail 
elsewhere  in  various  sections  of  this  treatise.  In  placer  deposits 
the  wire  gold  found  at  the  surface  is  commonly  ascribed  to  the 
reducing  action  of  grass  roots,  since  the  wires  often  assume  a  similar 
form.  The  occurrence  of  auriferous  pyrite  replacing  woody  matter 
in  alluvial  drifts  has  already  been  mentioned.  The  deposition  of 
gold  is  here  perhaps  not  directly  dependent  on  the  carbonaceous 
matter  but  on  the  pyrite  itself  reduced  by  the  woody  tissues. 

Numerous  instances  are  on  record  of  gold  in  the  ash  or  in 
the  pyrite  of  coal  or  coaly  matter.  The  ash  of  the  pyritous 
coal  of  Batu  Belaman  (Assem  Assem,  Tanah-Laut,  Borneo) 
contains  gold.6  Coaly  matter  intercalated  in  the  quartzites 
of  the  WitAvatersrand  occasionally  carries  high  tenors  in  gold, 
some,  indeed,  from  the  Buffelsdoorn  mine,  Klerksdorp,  assaying 
as  high  as  800  ounces  per  ton,  so  that  the  ash  was  coloured 
purple  by  the  gold.  The  gold  was  exceedingly  fine,  but  on  close 
examination  it  was  found  to  be  scattered  through  the  coal.  It 
was  only,  however,  in  the  immediate  neighbourhood  of  a  diabase 
dyke  that  the  coal  contained  gold  ;  elsewhere  in  the  mine 
it  was  barren/ 

A  notable  instance  also  occurs  in  California,  where,  in  the 
so-called  "  pocket  "  region  in  Tuolumne  County,  north  of  Sonora, 
pockets  of  gold  are  developed  only  where  a  silicified  porphyry 
dyke  crosses  a  carbonaceous  band  of  slated  Gold  is  also  reported 
from  the  coal  of  Gippsland,  Victoria.  Some  65  miles  south-west 
from  the  goldfield  of  Deadwood,  South  Dakota,  are  the  Cambria 
coal  seams.  The  coke  of  this  coal  is  stated  to  contain  between 
1  and  2  dwts.  gold,  assays  occasionally  showing  3  dwts.  The  coal 
is  used  in  smelting  the  gold-ores  of  Deadwood.6 

The  most  remarkable  instances  of  the  influence  of  carbonaceous 
matter    on    auriferous    deposition    are    furnished    by   the    Eastern 

^"Traitede  Chiraie  Minerale,"  Paris,  1906,  V,  602. 

h  Jaarb.  Mijnw.  Xed.  O.  Ind.,  1885,  II,  p.  114. 

c  Stephens,  Aust.  Min.  Stand.,  Sept.  8,  1904. 

^Min.  Sci.  Press,  June  6,  1908  ;  see  also  12th  Ann.  Rep.  State  Min.  Cal.,  p.  299.' 

eChenhall,  Proc.  Inst.  C.E.,  CXXXIX,  1900,  p.  326. 


EFFECT  OF  CARBONACEOUS  MATTER.  Ill 

Australian  goldfields  of  Ballarat  and  Gympie.  In  the  former  case 
auriferous  deposition  is  common  and  abundant  where  vertical 
carbonaceous  "indicator"  bands  are  intersected  by  flat  "floors'1 
of  quartz.  The  indicators  are  occasionally  highly  pyritous,  and, 
according  to  Gregory,  at  times  contain  rutile.  Deposition  of  gold 
here,  as  in  many  other  cases,  may  therefore  be  primarily  due  to 
the  presence  of  sulphides,  themselves  due  to  the  influence  of 
carbonaceous  matter.  It  is  not  probable  that  solid  carbon- 
aceous matter  plays  an  active  and  primary  part  in  auriferous 
deposition  ;  it  acts  rather  by  the  liberation  of  hydrocarbons  (liquid 
or  gaseous)  which  form  the  actual  reducers.  Again  it,  or  its 
products,  may  produce  -ous  salts,  which  are  then  the  immediate 
precipitants  of  gold.  That  carbonaceous  shale  is  a  ready  reducer 
in  nature  has  been  abundantly  proved  by  Rickarda  and  others. 

At  the  Gympie  goldfield  quartz-veins  intersect  bedded  Permo- 
Carboniferous  strata,  but  it  is  only  where  they  cross  carbonaceous 
shales  that  they  are  notably  auriferous.  At  Croydon,  in  Queensland, 
abundance  of  graphite  in  the  "  pug  "  of  the  veins  is  considered  a 
most  favourable  indication  of  high  tenors  in  the  gold-quartz.  The 
gold-quartz  lenses  of  the  eastern  side  of  the  Gadag  goldfield  in 
India,  follow  for  several  miles  a  narrow  carbonaceous  argillite  band. 
Instances  of  the  potent  reducing  effect  of  carbonaceous  matter  in 
veins  might  be  multiplied  indefinitely,  but  sufficient  has  been  said 
to  indicate  its  extreme  importance  in  the  formation  of  gold-deposits 
of  economic  value. 

Some  little  light  is  thrown  on  the  deposition  of  gold  by  a 
general  consideration  of  the  gangues  and  minerals  with  which  it 
is  commonly  associated.  How  numerous  these  are  has  recently  been 
shown  by  Merrill,  whose  list &  contains  48  members,  each  showing 
a  different  association  of  gold.  It  may  here  once  again  be  empha- 
sized that,  notwithstanding  this  long  list,  to  two  alone,  viz.,  to 
quartz  and  to  base  sulphides,  may  a  genetic* association  be  attributed. 
The  "  indicator  "  minerals  so  largely  relied  upon  on  various  fields 
have  a  purely  local  value,  and  no  general  deductions,  based  on  their 
presence  or  absence,  may  be  drawn  for  other  fields.  On  a  given 
field,  any  or  some  of  the  following  minerals  may  be  valuable 
indicators  :  calcite,  graphite,  chlorite,  serpentine,  native  arsenic, 
stibnite,  galena,  tetradymite,  chalcopyrite,  chalcocite,  pyrite, 
pyrrhotite,   pyrargyrite,   proustite,   and  others. 

Concentration  of  Gold  in  Nature. — Since  the  degree  of 
aggregation  of  gold  is  of  vital  importance  from  an  economic  point 
of  view,  it  is  necessary  to  briefly  review  the  causes  that  have  formed 

°  Trans.  Ainer.  Inst.  M.E.,  XXVI,  1897,  p.  978. 
h  Eng.  Min.  Jour.,  May  25,  1905,  p.  922. 


112  CONCENTRATION    OF    GOLD. 

not  only  the  notable  bonanzas  that  have  from  time  to  time  been 
found,  but  also  those  minor  aggregations  that  furnish  so  much 
of  the  Avorld's  present  supply  of  gold.  The  possible  sources  from 
which  the  gold  of  any  deposit  may  have  been  derived  are  :  (a) 
Emanations  from  igneous  magmas  ;  (b)  disseminations  throughout 
igneous  rocks  ;  (c)  pre-existing  auriferous  veins  ;  and  (d)  deposits 
mechanically  or  chemically  formed  in  sedimentary  rocks.  Some, 
or  all  of  these  may  have  been  affected  by  the  leaching  action  of 
the  waters  that  are  gathered  within  a  single  fissure.  Since  the 
motion  of  loaded  waters  in  fissures  is  mainly  upward,  and  since 
deposition  of  their  metallic  content  may  take  place  with  the  dimi- 
nution of  heat  and  pressure  that  obtains  as  they  near  the  surface, 
the  general  effect  of  motion  in  upward-moving  deep-seated  waters, 
is  towards  deposition  of  their  metallic  content  on  the  sides  of  the 
fissure.  For  gold,  precipitation  takes  place  either  in  the  mass  of 
baser  sulphides  or  as  tellurides.  With  long-continued  passage  of 
solutions  the  auriferous  sulphides  may  readily  be  conceived  to  grow 
in  bulk,  but,  to  the  growth  of  gold-tellurides  in  like  fashion,  the 
evidence  available  offers  certain  objections,  which  may,  neverthe- 
less, be  inapplicable  to  the  natural  conditions  of  telluride  depo- 
sition, of  which  we  are  profoundly  ignorant.  Lenher  and  Halla  have 
shown  that  the  natural  tellurides  of  gold  are  capable  of  readily 
reducing  gold  from  its  solutions.  Hence,  while  the  association  of 
free  gold  and  gold-telluride  is  readily  accounted  for,  there  is  reason 
to  believe  that  accretion  of  gold-telluride  to  gold-telluride  does 
not  take  place.  .Telluride  aggregations  are  perhaps  to  be  ascribed 
rather  to  the  long-continued  mingling  at  the  given  spot,  or  in  the 
given  fissure,  of  solutions  containing,  respectively,  gold  and  a 
telluride  compound.  In  such  fashion  there  may  be  formed  notable 
concentrations,  both  of  auriferous  sulphides  and  of  gold-tellurides. 
The  two  are  often  associated.  At  Kalgoorlie,  after  a  steady  decrease 
in  value  from  the  secondarily  enriched  telluride  zone  at  the  base 
of  the  vadose  region,  a  notable  and  probably  primary  enrichment 
has  been  noted  in  certain  mines  at  the  2,000-foot  level. 

The  agents  of  concentration  acting  on  the  surface  of  the  earth 
are  fluviatile,  peolian,  and  marine.  Of  these,  the  first  is  important, 
the  two  last  insignificant.  Their  relative  values  have  already  been 
indicated,  and  need  not  be  here  further  discussed. 

Local  factors  often  tend  to  produce  bonanzas.  These  will  be 
treated  separately  as  inducing  secondary  enrichment  and  as  forming 
shoots. 

Secondary  Enrichment. — The  aggregation  of  gold  with 
regard  to  its  matrix  may  be  increased  either  by  the  removal  of  a 

«  Jour.  Am.  Chem.  Soc,  XXIV,  1902,  p.  355;    Ibid.,  p.  918. 


SECONDARY    ENRICHMENT.  113 

portion  of  the  matrix  or  by  an  actual  addition  of  gold.  The  first 
is  a  relative,  the  second  an  actual  enrichment.  The  first  is  operative 
in  the  vadose  zone  or  the  zone  of  weathering,  where  complex  minerals 
are  decomposed  and  the  resultant  salts  removed  either  in  solution 
or  in  mechanical  suspension  in  running  water.  Notable  enrichments 
may  thus  occur  at  the  outcrops  of  veins,  especially  where  their 
contained  gold  is  coarse.  When  the  primary  gold  is  fine,  as  in  the 
case  of  the  great  Martha  lode  of  the  Waihi  mine,  the  outcrop 
gold  is  not  less  readily  removed  by  chemical  than  by  mechanical 
agents. 

The  great  proportion  of  the  work  of  secondary  enrichment  is 
performed  by  solutions  percolating  in  the  vadose  zone.  These 
may  be  divided,  according  to  the  nature  of  their  work  and 
its  result,  into  two  divisions  :  (a)  Ascending  solutions  depositing 
free  gold  as  near  the  outcrop  of  the  vein  as  possible  ;  (b)  descending 
solutions,  which  by  interaction  with  the  solid  and  liquid  contents 
of  the  fissures  of  the  deeper  zone  deposit  auriferous  sulphides  and 
gold-tellurides  at  or  near  the  base  of  the  vadose  zone.  For  both 
divisions  the  initial  process  of  solution  of  gold  is  the  same.  We  have 
already  considered  the  various  possible  natural  gold-solvents, 
and  also  the  precipitants  of  the  vadose  zone,  and  they  need  not  here 
be  recapitulated.  It  remains  but  to  trace  the  course  of  the  gold 
solutions.  Free  gold  may  conceivably  be  dissolved  within  the 
vadose  zone,  but  the  general  source  is  the  upper  sulphide  and 
telluride  horizon,  which  erosion  and  the  consequent  lowering  of  the 
ground-water  level  brings  within  the  reach  of  oxidising  waters. 
When  the  course  of  the  loaded  waters  is  upward  the  gold  may  be 
precipitated  in  the  free  state  by  one  of  its  numerous  precipitants,  or, 
as  is  probably  generally  the  case,  the  contained  gold  is  withdrawn 
from  solution  by  mass-action  exercised  by  grains  or  crystals  of  free 
gold.  Thus  are  grown  those  gold  crystals,  which,  as  we  have  seen, 
are  characteristic  of  the  vadose  zone  as  well  as  of  alluvial  gravels, 
and  thus  are  formed  the  notable  masses  of  gold  that  have  been  found 
in  the  gossan  of  the  deposit,  as  at  Mount  Morgan,  or  at  the  inter- 
sections of  fissures,  as  in  the  "  propylite  "  of  the  Thames  and  other 
andesitic  goldfields.  This  action,  though  perhaps  most  notable 
at  the  immediate  outcrop  of  veins,  since  there  it  represents  the  sum 
of  the  products  of  many  such  operations,  yet  takes  place  throughout 
the  whole  of  the  zone  of  weathering,  which  may,  indeed,  range  to 
many  hundreds  of  feet  in  depth.  At  moderate  depths  it  is  generally 
accompanied  by  the  formation  of  siliceous  veins  or  replacements  ; 
these  last  are  lacking  at  the  immediate  outcrop. 

In  the  second  division  of  secondary  enrichments,  where  the 
ultimate  course  of  the  gold-bearing  waters   is   downward  to  the 

H 


114  CONCENTRATION    OF    GOLD. 

top  of  the  sulphide  and  telluride  zone,  the  possible  reactions  are 
much  more  complex.  In  the  zone  of  weathering  the  sulphides  are 
oxidised  ultimately  to  oxides  and  sulphates  generally  in  the  following 
order. in  time:  arsenopyrite,  pyrite,  chalcopyrite,  blende,  galena, 
and  chalcocite,  the  first-mentioned  being  the  most  readily  attacked. 
Chlorides  and  carbonates  are  also  formed  in  the  zone  of  weathering. 
When  these  reach  the  sulphide  zone  on  the  downward  journey 
and  come  into  contact  with  the  reducing  waters  of  that  zone,  their 
metallic  content  is  deposited  in  a  variety  of  ways.  Organic  matter 
below  the  ground- water  level  has,  as  we  have  seen  in  the  case  of  the 
carbonaceous  bands  of  Bendigo  and  Gympie,  exercised  a  notable 
effect  in  this  directions  Sulphates  and  sulphites  are  probably  also 
reduced  to  sulphides  by  -ous  salts,  such  as  ferrous  silicates. b  Perhaps 
the  most  important  agent  in  the  formation  of  metallic  sulphides  in 
this  zone  is  sulphuretted  hydrogen,  which  is  of  wide  distribution 
in  underground  waters.    Alkaline  sulphides  may  also  be  operative. 

However  formed,  the  resultant  mineral  sulphide  contains 
all  or  some  of  the  gold  contained  with  it  in  the  solution.  At  the 
top  of  the  sulphide  zone  there  is  thus  a  notable  secondary  enrich- 
ment, both  of  sulphide  and  of  gold.  Thus  we  have  in  a  typical  gold 
vein  :  (a)  a  surface  oxidised  zone  characterised  by  free  gold,  (b) 
a  narrow  zone  of  enriched  auriferous  sulphides,  and  (c)  a  belt  of 
great  depth  of  original  lean  auriferous  sulphides.  The  contact 
between  the  first  two  zones  is  often  well  defined  ;  that  between 
the  two  last  is  rarely  so. 

It  is  believed  that  a  telluride  zone  of  secondary  enrichment 
may  be  formed  in  a  manner  somewhat  analogous  to  that  of  the 
enriched  sulphide  zone.  For  the  existence  of  such  a  zone  there  is 
abundant  evidence  both  at  Kalgoorlie,  Western  Australia,  and  at 
Cripple  Creek,  Colorado,  the  two  most  important  telluride  areas  at 
present  worked. 

The  apparent  comparative  insusceptibility,  in  the  oxidised 
zone,  of  gold  to  solvents,  the  accumulation  of  gold  in  that  zone 
as  the  vein  is  slowly  worn  away  by  erosion,  the  removal  of  much 
of  the  vein-matter  by  decomposition  and  weathering  leaving 
cavities  and  vughs,  and  the  constant  reinforcement  of  its  gold 
contents  from  the  enriched  sulphide  zone,  all  tend  to  render  the  tenor 
of  a  given  vein  in  the  oxidised  zone  greatly  higher  than  in  the 
primary  lean  sulphide  zone  far  below.  Notable  exceptions  to  this 
rule,  arising  from  special  conditions,  are  known  (Waihi,  &c),  and 
have  been  indicated  elsewhere  in  this  volume.  Owing  probably 
to   slowness  of    oxidation  in    boreal    regions,    as    Alaska,    British 

a  See  also  Jenney,  Trans.  Amer.  Inst.  M.E.,  XXXIII,  1903,  p.  445. 
b  Van  Hisc,  Mon.  U.S.  Geol.  Surv.,  XLVII,  1902,  p.  1112. 


SHOOTS.  115 

Columbia,  Siberia,  &c,  secondary  enrichments  are  there  very 
rare,  even  the  pyrite  in  surface  gravels  showing  no  tendency  to 
oxidation  and  consequent  liberation  of  its  contained  gold. 

Shoots. — Local  enrichments  or  aggregations  of  gold  are  called 
"shoots,"  "chimneys,"  "bonanzas,"  "pockets,"  or  "pay- 
streaks,"  according  to  their  general  shape.  Ore-deposits  vary  at 
times  in  tenor  and  in  shape  with  remarkable  suddenness.  The  study 
of  the  conditions  governing  their  formation  is  one  of  extreme 
difficulty,  since,  in  the  course  of  time,  many  changes,  physical 
and  chemical,  may  have  taken  place  in  the  adjacent  country,  all 
tending  to  obliterate  the  essential  features  in  existence  at  the  period 
of  formation  of  the  ore-shoot.  It  is  characteristic  of  shoots 
within  a  vein  that  they  possess  not  only  the  dip  of  the  vein,  but  a 
pitch  to  one  side  or  the  other  within  the  vein  itself.  In  given  veins 
a  general  parallelism  of  successive  shoots  may  often  be  observed. 
Shoots  may  be  rudely  divided  into  three  classes,  according  to  their 
probable  method  of  origin  or  to  the  causes  that  have  affected 
their  deposition  : — 

( 1 )  Shoots  due  to  structural  features  in  fissure  or  in  country. 

(2)  Shoots  due  to  the  influence  of  wall  rocks. 

(3)  Shoots  due  to  the  influence  of  descending  waters. 

No  sharp  division  may  be  made  between  these,  since  more 
than  one,  or  all  three,  may  have  been  combined  to  form  a  given 
shoot.  Other  causes  beside  those  given  may  operate,  and  the  history 
of  any  shoot  may  be  traced  only  on  the  field  on  which  it  occurs, 
and  then  only  when  in  possession  of  abundant  geological  data 
derived  from  that  field. 

Where  ore-bodies  are  formed  by  simple  filling  of  fissures,  their 
shape  is  naturally  dependent  on  the  conditions  that  have  directed 
or  modified  the  formation  of  the  fissures.  Since  fissures  are  generally 
also  fault-lines,  the  irregularities  of  the*  walls  are  so  opposed  by 
dislocation  that  the  subsequent  ore-body  presents  a  succession  of 
swellings  and  pinchings.  This  takes  place  not  only  vertically, 
but  also,  to  a  more  limited  extent,  laterally.  Faulting  along  a 
fissure  may  therefore  mean  the  local  discontinuity  of  the 
ore-body  subsequently  formed.  The  openings  of  a  fissure  due  to 
fracture  and  dislocation  are  greatly  enlarged  and  modified  by  the 
solvent  action  of  passing  waters.  Solution  may  be  simple  or  may 
be  accompanied  by  metasomatic  replacement.  An  ore-body,  there- 
fore, tends  to  widen  on  passing  from  a  less  to  a  more  soluble  rock. 
The  mass  of  metal  is  often  greater  in  wider  parts  of  the  ore-body 
owing  to  the  greater  amount  of  solution  contained  within  the  wider 
cavity,  but  no  general  statement  may  be  made  under  this  head. 
Often  the  narrower  portions  of  an  ore-body  are  much  the  richer, 


116  CONCENTRATION    OF   GOLD. 

and  in  these  cases  it  may  be  observed  that  the  total  quantity  of 
gold  contained  within  the  ore-body  at  selected  horizons  is  fairly 
constant,  but  that  in  the  wider  portions  it  is  merely  distributed 
through  a  greater  mass  of  gangue. 

Successive  movements  along  the  same  fault-line  may  re-open 
a  mineral-filled  fissure  and  permit  of  the  further  deposition  of  ore. 
This  process  may  be  repeated  until  a  notable  aggregation  results. 
The  walls  of  a  main  fault-fissure  may  be  so  deeply  affected  by 
movement  that  adjacent  bands  of  numerous  minor  parallel  and 
interlacing  fissures  may  form  in  the  country,  thus  affording  a* 
ready  passage  for  mineral-bearing  waters  and  abundant  oppor- 
tunity for  replacement  of  the  brecciated  country  by  ore.  Interlacing 
stringers  (stockworks),  especially  in  propylite  regions  as  those  of 
Transylvania,  Colorado,  and  New  Zealand,  are  favourable  to  ore- 
deposition,  probably  because  opportunity  is  afforded  for  the  inter- 
mingling of  solutions  containing  the  metallic  salt  and  the  pre- 
cipitant respectively. 

The  line  of  intersection  of  fractures  or  fissures  is  always  a 
possible  locus  of  an  ore-body.  Since  these  may  meet  in  any  line  at  any 
angle  from  the  horizontal  or  from  the  vertical,  any  given  disposition 
of  ore-body  may  result.  Local  variations,  either  towards  poverty 
or  richness,  may  arise  in  shoots  of  this  character,  from  the  fact  that 
the  precipitating  or  the  metalliferous  solution  may  have  egress 
and  may  be  intermingled  with  the  waters  of  the  other  channel  only 
at  given  points  along  the  line  of  intersection.  A  remarkable  instance 
of  the  secondary  development  of  an  ore-shoot  along  the  line  of 
intersection  of  two  fissures  is  afforded  by  the  "  chimney  "  of  the 
Bassick  mine,  Colorado,  where  igneous  matter  has  taken  advantage 
of  the  line  of  weakness  so  formed  to  the  surface,  and  has  welled  up 
along  it,  shattering  the  walls  and  forming  a  pipe  elliptical  in 
plan  of  brecciated  material.  The  ore-body  consisted  of  the  central 
portion  of  the  breccia,  this  portion  apparently  remaining  the  channel 
for  ascending  solutions. 

A  remarkable  form  of  ore-body  is  furnished  by  the  "  saddle- 
reefs  "  of  Victoria  and  Nova  Scotia,  where  ore-bodies  are  developed 
at  given  horizons  within  the  rocks  at  the  crests  of  anticlinal  folds, 
or  more  rarely  at  the  bottoms  of  synclines.  Minor  flexures  carrying 
ore-bodies  may  also  be  developed  on  the  sides  of  the  main  folds, 
and  these,  as  in  Nova  Scotia,  may  carry  shoots.  The  shoots  of  the 
Champion  Reef,  India,  perhaps  the  most  notable  worked  in  the 
history  of  gold-mining,  are  apparently  due  to  combined  vertical 
and  longitudinal  compressions,  the  resultant  of  which  is  midway 
between  horizontal  and  vertical  and  is  in  the  strike  of  the  vein. 
Along  the  resultant  line,  therefore,  there  have  been  opened  channels. 


SHOOTS.  117 

for  the  passage  of  the  auriferous  waters,  and  along  the  same  line 
the  already-formed  quartz-vein  has  been  folded  over  to  form  the 
rolls  characteristic  of  the  Champion  Reef.  As  might  be 
expected,  the  Kolar  shoots,  like  those  of  many  other  veins  in 
other  parts  of  the  world,  are  parallel  in  "  pitch,"  which  is  here 
understood  as  the  dip  of  the  shoot  within  the  plane  of  the  vein. 
In  fairly  steep  veins  it  is  probable  that  the  direction  and  the  velocity 
of  flow  of  metalliferous  waters  are  important  factors  in  governing 
the  'L  pitch  "  of  an  ore-shoot  formed  by  the  intermingling  of  waters 
from  intersecting  fissures.  In  this  case  the  position  finally  occupied 
by  the  gold  grain  lies  along  the  line  resultant  from  the  com- 
bination of  the  motions  imparted  to  the  grain  by  the  moving 
waters  and  by  gravity  respectively.  Even  in  a  slowly-moving 
current  a  fine  particle  of  gold  may  be  carried  a  considerable  distance 
before  coming  to  rest.  In  other  cases,  as  on  the  Maldon  goldfield, 
Victoria,  the  pitch  of  auriferous  shoots  is  dependent  on  the  dip  of  a 
given  stratum  and  the  underlie  of  the  vein,  since  it  is  only  along 
the  intersection  of  bed  and  vein  that  shoots  are  developed." 

We  have  seen  that  ore-shoots  may  be  due  to  the  influence  of  wall- 
rocks,  and  those  due  to  the  action  of  carbonaceous  rocks  have  also 
been  indicated  with  sufficient  detail.  In  readily  soluble  rocks,  as  lime- 
stones, traversed  by  fissures  through  which  auriferous  silica-bearing 
solutions  are  passing,  widespread  metasomatic  replacement  adjacent 
to  the  fissures  may  result.  When  metasomatism  is  accompanied  by 
auriferous  deposition,  as  has  been  the  case,  e.g.,  at  Pilgrims's  Rest, 
Transvaal,  and  Tintic,  Utah,  the  ore-body  may  assume  considerable 
economic  importance.  Again,  in  the  northern  goldfields  of  Western 
Australia,  the  peculiar  banded  hsematite-magnetite-quartz  rocks 
of  the  Archaean  schists  are  auriferous  only  where  they  are  intersected 
by  transverse  fissures.  Finally,  a  wall-rock  may,  on  leaching,  furnish 
the  metalliferous  contents  of  the  veins  by  which  it  is  traversed. 
The  propylitic  rocks  of  the  Tertiary  andesites  may  thus  have 
furnished  some  portion  of  the  gold  of  their  stringers  ;  this  assumption 
is  based  on  analyses  of  the  country  of  the  Comstock  Lode,  and  of 
similar  rocks,  but  it  is  doubtful  whether  much  of  the  evidence 
offered  a  quarter  of  a  century  ago  is  now  admissible. 

A  further  cause  of  ore-shoots  is  the  precipitation  from  down- 
ward-moving solutions  that  takes  place  at  the  top  of  the  sulphide 
zone.  Their  formation  has  been  fully  indicated  under  secondary 
enrichment.  As  already  seen,  shoots  of  this  type  are  more  or  less 
horizontal  in  disposition,  and  extend  only  to  comparatively  shallow 
depths  below  the  zone  of  oxidation. 


aMoon,  Rep.  Mines  Dept.  Victoria,  1895. 


119 


PART    II. 

The  Geographical  Distribution  of  Gold. 


EUROPE. 

The  auriferous  deposits  of  Europe  comprise  three  great  groups 
and  a  number  of  minor  occurrences,  the  latter  not  being 
obviously  related  to  each  other  or  to  the  main  groups. 
Two  of  the  groups,  viz.,  those  of  the  Ural  mountain  chain  and  of  the 
Hungarian  Miocene  andesitic  lavas  and  tuffs  possess  considerable 
economic  value  ;  the  third,  or  Alpine  group,  which  ranges  from 
Carinthia  through  the  Austrian  Tyrol  and  the  Italian  Alps  to  the 
Pyrenees  and  the  Cantabrian  Alps,  is  of  minor  importance. 

The  gold- veins  of  the  Urals  are  apparently  dependent  for  their 
origin  on  late  Palseozoic  igneous  activity,  though  it  is  not  clear 
whether  they  are  to  be  ascribed  to  acid  or  to  basic  magmas  ;  most 
probably  to  the  latter,  though,  as  at  Berezovsk  and  at  Kotchkar, 
they  occur  in  microgranitic  and  granitic  country.  It  is  possible, 
however,  that,  as  in  California  and  in  Eastern  Australia,  they 
are  all  to  be  referred  to  a  single  protracted  period,  during 
which  magmatic  differentiation  produced  both  acid  and  basic 
rocks.  On  the  other  hand,  the  relations  of  the  Hungarian  occur- 
rences (of  which  the  principal  fields  are  Schemnitz,  Kremnitz, 
Nagybanya,  and  those  of  the  Transylvanian  Alps)  are  very 
clear,  and  auriferous  impregnation  is  there  certainly  dependent  on 
the  extrusion  in  Miocene  time  of  dacites  and  normal  andesites. 
The  third  or  Alpine  group  contains  numerous  sporadic  occur- 
rences along  the  belt  above  indicated.  These  are  all  in  the  Permo- 
Carboniferous  schistose  rocks  of  the  Alpine  uplift,  and  in  some 
cases,  at  least,  would  appear  to  have  arisen  from  dioritic  or  diabasic 
intrusions.  It  is  noteworthy,  however,  that  tonalite  rocks  have 
been  extruded  on  the  eastern  and  southern  side  of  the  schistose 
rocks. a  The  Italian  gold-quartz  veins  have  proved  the  most 
important  of  the  group. 

Of  isolated  occurrences,  the  gold  of  the  North  Wales  area  in 
Middle  Cambrian  strata  is  perhaps  connected  with  diorites  and  dia- 

a  De  Launay,  Cornptes  Rend.  Congres  Geol.  Internat.,  1906,  p    586. 


120 


EUROPE. 


basic  rocks,  as  also  is  that  of  Norway  in  metamorphic  rocks.  The 
Carboniferous  conglomerates  of  Western  Europe  appear  in  places 
to  be  slightly  auriferous,  but  no  guess  may  be  hazarded  as  to 
whether  their  contained  gold  is  due  to  impregnation  or  is  in  point 
of  deposition  contemporaneous  with  that  of  the  conglomerate. 

ENGLAND. 

Cornwall. — Of  the  production  of  gold  in  Cornwall  and  Devon 
in  early  times  there  are  no  records,  but  that  from  time  to  time  the 


ORKNEV  ISLAND: 


LOOALITY-MAP 
OF 

GREAT      BRITAIN 

AND 

prtli  IR  ELAN  D 


NORTH   s e n 


Fig.  72.     Auriferous  Localities  in  Great  Britain  and  Ireland.  ' 

gold  mines  of  these  counties  were  considered  sufficiently  remunera- 
tive to  be  worked  is  evidenced  by  the  numerous  writs  and  grants  of 
Henry  III,  and  of  his  successors  down  to  Elizabeth.  With  all 
these,  however,  not  a  single  ounce  of  gold  is  recorded  as  having  been 
obtained.  In  1564  a  patent  or  monopoly  was  granted  to  William 
Humphreys,  Cornelius  Devos,  Daniel  Hochstetter,  and  Thomas 
Thurland,  to  seek  for  gold,  silver,  and  quicksilver  in  certain  counties 
in  England,  Wales,  and  Ireland  within  the  Pale.     This  patent  was 


ENGLAND.  121 

confirmed  and  amplified  by  James  I,  and  became  the  charter  of  the 
Mines  Royal  Company,  which  existed  and  claimed  the  right  to  all 
royal  metals  until  after  the  middle  of  the  nineteenth  century.  It 
does  not  appear,  however,  that  their  operations  at  any  time  met 
with  any  degree  of  success.  In  the  early  part  of  the  last  century, 
gold  was  obtained  in  small  quantities  at  Ladock  by  Sir  Christopher 
Hawkins.  A  specimen  presented  by  him  to  the  Royal  Geological 
Society  of  Cornwall  was  enclosed  in  a  quartz-matrix. 

In  1753,  certain  tin-streamers  in  the  parish  of  Creed,  near 
Grampound,  met  with  some  grains  of  gold,  and  "  in  one  stone  a 
vein  of  gold  as  thick  as  a  goose  quill  was  found."  Shortly  after, 
gold  was  discovered  in  blue  sandy  slate  at  Luny  in  the  parish  of 
St.  Ewe.  A  little  gold-ore  is  reported  to  have  been  obtained  in 
18-16,  at  Wheal  Samson,  in  St.  Teath.  In  1852  gold  was  discovered 
in  quartz-veins  at  Davidstowe,  North  Cornwall. 

Borlase  mentions  that  he  had  seen  a  nugget  from  the  parish 
of  Creed,  near  Grampound,  weighing  15  dwts.  3  grains.  Gold  was 
also  found  in  the  Crow  Hill  stream  works  at  Trewarda,  at  Kenwyn, 
and  at  Llanlivery,  near  Lostwithiel.  In  the  British  Natural 
History  Museum  there  is  exhibited  a  small  water-worn  nugget 
from  Wendron,  near  Helston.  Gold  is  also  reported  from  Cornwall 
in  the  matrix  from  a  cross-course  in  Huel  Sparnon,  and  in  the  gossan 
of  the  Nargiles  mine.  Forbes  records  the  presence  of  gold  in  the 
argentiferous  tetrahedrite,  chalcopyrite,  and  galena  of  a  lode  at 
Bound's  Cliff,  near  St.  Teath. 

Native  gold  has  been  found  in  most  of  the  Cornish  tin-streams 
flowing  to  the  south.  Of  these  the  Carnon  stream,  at  the  head  of 
Restronget  creek  in  the  Falmouth  estuary,  has  perhaps  yielded  the 
most  specimens.  Small  nuggets  are  not  uncommon  there,  and  one 
found  at  Carnon  is  reported  to  have  weighed  more  than  10  guineas, 
and  was  probably  about  2  ounces  in  weight.  The  gold  is  generally 
found  associated  with  stream-tin.  Analysis  of  several  grains  from 
St.  Austell  Moor,  the  largest  of  which  was  only  2  ■  1  grains  in  weight, 
gave  Forbes  the  following  result  :  Gold,  90*12  ;  silver,  9*05  ;  and 
silica  and  iron,  0  ■  83  per  cent.  The  specific  gravity  of  the  gold 
was  15*62.  Gold  from  Ladock,  analysed  by  Church,  proved  to  be 
slightly  finer  in  quality  than  the  above  :  Gold,  92  34  ;  silver, 
6*06  ;    and  silica,  1*60  per  cent. 

Devon. — In  this  county  the  existence  of  gold  has  been  known 
or  assumed  for  many  centuries.  In  the  beginning  of  the  nineteenth 
century,  a  miner  named  Wellington  is  reported  to  have  found  gold 
at  Sheepstor  on  South  Dartmoor.  At  different  times  he  brought 
to  a  silversmith  at  Plymouth  quantities  which  in  the  aggregate 
were  valued  at  about    £40.      The  principal  auriferous  locality  in 


122  EUROPE. 

Devon  is  at  North  Molton.  Here,  in  1852,  the  gossan  ores  of  the 
Britannia  and  Poltimore  mines  were  discovered  to  be  payably 
auriferous.  This  discovery,  coming  immediately  after  the  world- 
wide excitement  and  unrest  caused  by  the  discovery  of  the  Cali- 
fornian  diggings,  attracted  an  extraordinary  amount  of  interest. 
The  first  trial  of  the  gossan  yielded  26|  ozs.  from  20  tons  of  ore, 
and  the  average  yield  of  further  trials  of  50  and  75  tons  was  6  dwts. 
per  ton.  The  gold  was  of  very  good  quality,  and  was  said  to  be 
worth  nearly  £4.  4s.  per  ounce.  The  total  value  of  the  gold 
produced  from  the  Poltimore  mines  up  to  November  2nd,  1853,  was 
£581.  5s.  Id. 

The  North  Molton  auriferous  copper  lodes  are  situated  in  an 
area  of  Devonian  rocks,  some  distance  away  from  an  exposed 
contact  with  the  overlying  Carboniferous  sandstones.  Both  the 
Devonian  and  Carboniferous  strata  are  very  highly  inclined,  being 
at  times  even  vertical,  and  the  lodes  appear  to  dip  with  the  country. 
The  chief  auriferous  gossan-lode  is  from  4  to  10  feet  wide,  and 
dips  to  the  north.  There  is  considerable  evidence  of  this  mine  having 
been  worked,  probably  for  copper,  in  very  remote  times.  The 
auriferous  gossan  is  a  friable  ironstone,  highly  mineralised,  and  con- 
taining copper.  It  is  brown  on  the  western  side  of  the  Mole  and 
reddish  on  the  eastern  bank.  The  latter  portion  of  the  vein  is 
reputed  to  be  twice  as  valuable  as  the  former,  assays  giving  17  dwts. 
and  8  dwts.  gold  respectively.  The  Britannia  mine  is  three-quarters 
of  a  mile  north  of  the  Poltimore.  Gold  was  found  there,  in 
grains  and  small  plates,  prior  to  1822.  It  likewise  carries  a  gossan 
ore,  which  is  more  siliceous  than  that  of  the  Poltimore.  These 
gossans  arise  from  the  decomposition  of  slightly  auriferous  metallic 
sulphides,  mainly  iron-pyrites.  In  a  specimen  from  North 
Molton,  in  the  British  Museum,  small  particles  of  gold  are  clearly 
visible  in  the  brown  and    somewhat  siliceous  ironstone. 

Cumberland. — Gold  is  said  to  have  been  formerly  recovered 
from  the  rich  copper-ore  of  Goldscope,  Keswick,  Cumberland,  but 
no  specimens  have  been  obtained  in  modern  times. 

Somerset. — Gold  has  been  recorded  from  the  Carboniferous 
Limestone  near  Bristol.  Appreciable  quantities  of  both  gold  and 
silver  have  been  found  in  the  limestone  at  Whalton,  near  Clevedon. 
One  sample  on  assay  contained  94  grains  of  silver  and  another 
nearly  1  ounce  of  silver  ;  while  both  returned  3  to  5  grains  of  gold 
per  ton.  In  the  absence  of  proof  of  the  absolute  purity  of  the 
fluxes  used  (and  especially  of  the  litharge),  these  results  must  be 
received  with  some  degree  of  caution. 

Gloucester. — During  1907  the  discovery  of  auriferous  con- 
glomerates was  reported  from  Gloucester  (Forest  of  Dean),  1 J  miles 


WALES.  123 

south-west  by  south  of  Mitcheldean,  where  siliceous  pebbly  con- 
glomerates were  found  to  carry  about  6  grains  gold  per  ton.  Their 
present  importance  is,  however,  negligible." 

WALES. 

Of  the  early  Roman  gold-workings  in  Wales  there  are  no 
authentic  remains,  but  it  has  generally  been  supposed  that  the  old 
workings  of  Ogofau,  near  the  village  of  Pumpsant,  some  12  miles 
west  of  Llandovery,  are  evidences  of  Roman  occupation  and  of  their 
search  for  gold.  The  name  Ogofau  or  Gogofau  is  probably  Ogofawr, 
designating  a  large  cave  or  large  disused  workings,  Ogo  being  a 
generic  term  for  such  old  excavations.  At  this  spot,  numerous 
remains  of  Roman  pottery,  ornaments,  and  baths  have  been 
found.  Some  of  the  ornaments  are  of  gold,  and  show  consider- 
able artistic  skill.  Grooved  stones,  on  which  the  crushing 
of  the  quartz  was  performed,  also  occur  in  the  neighbourhood. 
The  workings  are  extensive,  and  have  evidently  been  opened 
first  along  the  cap  of  the  lodes.  When  these  open  cuts  became 
too  deep  for  easy  working,  levels  170  feet  long,  6  feet  high,  and 
5  to  6  feet  wide,  were  driven  through  the  country  to  cut  the  lode. 
The  upper  level  communicated  with  the  opencast  workings  by 
a  rise,  and  the  lower  and  upper  levels  were  similarly  connected. 
The  workings  are  in  Lower  Silurian  rocks,  which  here  dip  slightly 
to  the  northward.  The  lodes  are  of  quartz,  and  vary  both  in  dip 
and  strike.  The  quartz  is  massive  and  somewhat  opaque,  showing 
in  places  a  tendency  to  form  interpenetrating  growths  of  crystals. 
The  accompanying  minerals  are  iron-pyrites,  in  cubes  and  pyrito- 
hedra,  and  a  little  galena.  A  white  sericitic  mica  and  inclusions 
of  slate  are  not  uncommon.  The  slates  when  fine-grained  are 
very  dark  and  very  fissile,  and  through  them  run  occasional 
thin  veins  of  greenish  blue  serpentinous  mineral.  Gold  was 
first  noted  at  Ogofau  in  modern  times  by  Sir  W.  Warington 
Smyth  and  Dr.  Percy,  though  Sir  Roderick  Murchison  had  some 
years  previously  submitted  the  quartz  to  assay  without  result. 
The  Ogofau  veins  were  worked  for  a  short  time  (during  1889 
to  1891)  by  the  South  Wales  Gold  Mining  Company,  but  the  results 
Mere  extremely  discouraging,  the  total  return  of  gold  being  only 
4  ozs.  19  dwts.  The  mine  was  soon  abandoned,  but  work  was 
resumed  about  1903,  and  the  veins  have  since  been  further  opened  up 
by  private  enterprise.  A  small  5-stamp  battery  was  erected  to  deal 
with  the  ore,  and  in  1905-1906,  some  800  tons  of  quartz  and 
ancient  tailings  were  crushed  for  a  yield  of  92  ounces  of  gold.  In 
1907  the  mine  passed  into  the  possession  of  a  small  company. 

aCullis  and  Richardson,  Proc.  Cottesw.  Nat,  F.  C,  XVI,  1907,  p.  81. 


124  EUROPE. 

North  Wales. — The  auriferous  veins  of  Merionethshire,  in 
North  Wales,  appear  to  have  been  discovered  in  1843,  the  occur- 
rence of  gold  in  that  county  being  reported  to  the  1844  meeting 
of  the  British  Association  for  the  Advancement  of  Science. 
In  1846  an  attempt  was  made  to  raise  capital  to  work  the  gold- 
mines, but,  owing  to  the  ridicule  cast  on  the  project,  the  attempt 
resulted  in  failure.  Early  in  1847  the  Vigra,  Clogau,  Tyddyn- 
gwladys,  and  Dol-y-frwynog  lodes  were  opened  up.  The  last 
mentioned  yielded  a  little  gold  during  1847,  but,  being  in  places 
12  feet  wide  with  good  copper-ore,  it  was  worked  almost  entirely 
for  the  latter  metal. 

Before  January,  1849,  the  first  extensive  trials  of  Welsh 
auriferous  veins  had  been  made  at  Cwm  Eisen,  and  7  lbs.  of  gold  of 
the  approximate  value  of  £350  had  been  obtained  from  lOf  tons  of 
concentrates,  the  produce  of  300  tons  of  ore.  Gold-mining  operations 
were  at  this  time  much  hindered  by  the  claims  of  the  Mines  Royal 
Corporation,  to  which,  as  we  have  already  seen,  the  Crown  had 
granted,  by  patents  of  Elizabeth,  its  royal  prerogative  in  Wales. 
The  matter  was  finally  settled  by  the  Crown  requiring  a  royalty  of 
5  per  cent,  on  private  property  and  of  10  per  cent,  on  Crown  land. 
In  1853,  a  great  impetus  was  given  to  gold-mining  in  Wales  by  the 
introduction  of  the  Berdan  machine  for  gold-recovery.  It  came 
at  the  height  of  the  excitement  caused  by  the  gold  discoveries 
in  California,  and  created  a  mild  boom,  of  which  the  usual 
advantage  was  taken  by  unscrupulous  persons.  At  that  time,  gold 
was  reported  from  all  parts  of  England  and  Wales,  nearly  all  the 
alleged  discoveries  being,  of  course,  fictitious.  The  gold  mines 
worked  during  this  boom  were  all  about  the  upper  waters  of  the 
Afon  Mawddach,  in  the  vicinity  of  the  Rhaiddr  Mawddach. 

On  August  16th,  1853,  gold  was  discovered  at  the  Prince  of 
Wales  mine  (later  the  Voel  mine),  about  half  a  mile  west  of  the 
junction  of  the  Mawddach  with  the  Afon  Wen,  and  in  the  same  week 
a  similar  discovery  in  an  old  dump  was  made  at  Vigra  (Clogau  ?)  by 
Messrs.  Goodman  and  Parry,  of  Dolgelly.  In  1854,  a  single  piece 
of  stone  worth  £25  was  crushed  from  Clogau,  and  two  years  later 
100  lbs.  of  quartz  from  the  same  mine  yielded  14£  ounces  of  gold. 
It  was  not,  however,  until  1860,  that  the  St.  David's  lode  of  the 
Clogau  mine  gave  any  indication  of  the  presence  of  rich  bonanzas. 
On  May  21st,  1860,  a  mass  of  15  cwt.  of  gold-quartz  of  the  estimated 
value  of  £500  to  £600  was  broken  down.  During  the  first  half-year 
of  1861,  983  ounces  of  the  value  of  £3,664  were  obtained.  This 
rich  discovery  naturally  stimulated  enterprise  in  the  vicinity  ;  and 
in  1863  the  Clogau,  Cefn  Coch,  Dol-y-frwynog,  and  Cwm  Eisen 
mines  were  being  vigorously  worked,  and  visible  gold  was  obtained 


WALES. 


125 


at  Garth-gell,  Cambrian,  Cae-Mawr,  Prince  of  Wales,  Moel  Offryn, 
Glasdir,  Tyddyn-gwladys,  and  Ganllwyd  mines.  In  April,  1862,rgold 
was  met  with  in  situ  in  the  Berthllwyd  mine,  near  Tyn-y-groes,'  and 
a  crushing  of  332^  tons  from  the  adjacent  Welsh  Gold  Mining 
Company's  mines  gave  a  yield  of  282J  ounces  of  gold.     The  gold 


Geological  Sketch-map 

OF  THE  '■'■■'■'(] 

■  Auriferous  District  of  North  Wales.       ' : ' ' '  ■  '■ 

Alluvium  ....  fc^^d) '. 

U»««  Oamsbiah-Bala  Aoe.-Diaba6Es.  Dolbrites.  etc. 
■  •  n  ,       AntNia  Aqe.-Acio  Intrusives,  «to. 

MlOOLE   CaMBBIAN— LmOULA  Flao  SERIES.  — DOLOELLV  BeOS 

"  ii  i.  ti  FpesTiNioa  Beds 

"  II  II  MaSNTWBOO  BEOS  J 

(.owes  Caubdian-Mimiviah  Series  .      » 

•  ■  >■  Harlech  Series  J    '■'•'      '  ■' 

Faults  ■ 


Veins 


Fig.  73.     Geology  or  the  Auriferous  Akea  of  the  Mawddach  Valley,  North  Wales. 

of  the  Gwyn-fynydd  lode,  which  yielded  so  handsomely  a  quarter 
of  a  century  later,  was  discovered  early  in  1864  by  Capt.  Griffith 
Williams,  but  the  discovery  was  kept  secret  until  February  23rd. 
1864.  In  1865,  the  Clogau  mine  paid  £22,575  in  dividends  and  had 
in  little  more  than  three  years  produced  gold  to  the  value  of  £43.783. 


126 


EUROPE. 


After  1866,  gold-mining  languished  for  nearly  20  years,  and 
there  is  little  of  importance  to  note  in  that  period.  The  Vigra  and 
Clogau  mines  had  worked  out  their  bonanzas,  and  in  1868  produced 
only  490  ounces  of  gold.  In  1870,  the  total  yield  from  Wales  was 
only  191  ounces,  of  which  Gwyn-fynydd  contributed  165  ounces. 
During  the  following  year  not  a  single  ounce  of  gold  was  produced. 

The  following  table  shows  the  yield  of  gold  from  Wales 
from  1861-1906  inclusive  :— 


Year. 


1861 
1862 
1863 
1864 
1865 
1866 
1867 
1868 
1870 
1874 
1875 
1876 
1877 
1878 
1879 
1880 
1882 
1883 
1885 
1887 
1888 
1889 
1890 
1891 
1892 
1893 
1894 
1895 
1896 
1897 
1898 
1899 
1900 
1901 
1902 
1903 
1904 
1905 
1906 


Gold  Ore. 


Tons.  Cwts. 


803 
385 
2,336 
4,280 
2,928 
3,241 
1,191 


14 
15 
10 
15 
0 
4 
10 


869 

0 

35  „ 

0 

0 

17 

3,844 

0 

6,226 

0 

575 

0 

14,067 

0 

9,990 

0 

4,489 

0 

6,603 

0 

13,266 

0 

2,765 

0 

4,517 

0 

703 

10 

3,047 

0 

20,802 

0 

16,374 

0 

29,953 

0 

28,600 

0 

23,203 

0 

15,981 

0 

17,384 

0 

t222,389  10 


Gold. 
Crude   Ounces. 


Ozs. 

2,886 

5,299 

552 

2,887 

1,664 

742 

1,520 

435 

191 

385 

548 

288 

139 

697 

447 

5 

226 

66 

3 

58 

8,745 

3,890 

206 

4,002 

2,835 

2,309 

4,235 

6,600 

1,352 

2,032 

395 

3,327 

14,004 

6.225 

4,181 

5,495 

19,655 

5,797 

1,871 


Dwts.  Grs. 

3  0 

1  12 

12  19 

0  0 

11  0 

16  10 

6  21 

14  23 

0  0 


0  12 

1  21 


18 
4 


7 
0 
0 
0 

10 
0 
0 
0 
0 
7 
0 
0 
0 
0 

10 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 


6 
13 


12     16 


21 

0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 


Value  of  Gold. 


116,197     19      8 


10,816 

20,390 

1,747 

9,991 

6,408 

2,859 

5,853 

1,677 

735 

1,477 

2,105 

1,119 

536 

2,825 

1,790 

19 

863 

254 

13 

209 

29,982 

13,277 

675 

13,700 

10,511 

8,619 

14,811 

18,528 

5,035 

7,185 

1,299 

12,086 

52,147 

22.042 

14,570 

19,308 

73,925 

21,222 

6,569 


17  0 

15  5 

0  0 

0  0 

10  0* 

7  10* 

3  5* 

12  9* 

7  0* 
6  11* 

17  6 

10  9 

0  4* 

8  6 
0  0 
5  0 
0  0 
2  0* 

9  6* 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 
0  0 


£417,183  13  11 


*  Estimated,  at  £3.   17s.  per  ounce  of  crude  gold, 
t  From  1888  to  1906  inclusive. 


WALES. 


127 


In  1881,  a  low-level 'tunnel  was  driven  to  intersect  the  St. 
David's  lode  (Clogau  mine)  ;  shortly  afterwards  a  small 
pocket  of  225  ounces  was  obtained.  Nothing  of  importance 
was  recorded  from  the  district  until  1888,  when  a  rich  shoot  was 
discovered  in  the  Gwyn-fynydd  lode.  The  Morgan  Company  was 
floated  to  work  this  mine,  which,  in  two  years,  produced  over  £35,000 
worth  of  gold.  After  the  exhaustion  of  the  shoot,  the  company 
suspended  operations  ;  but  a  new  company  was  formed,  and  carried 
on  operations  for  many  years,  with  varying  success.  The  two 
most  important  mines,  the  Clogau  and  the  Gwyn-fynydd,  were  then 
united  as  the  St.  David's  Gold  and  Copper  Mines,  Ltd. 

The  recent  yields  of  the  two  principal  lodes  near  Dolgelly  are 
shown  in  the  subjoined  table  : — 


Gwyn  Mines. 

St.  David's 

,  Dolgelly. 

Tons. 

Ounces. 

Tons. 

Ounces. 

1901 

726 

622 

15,517 

5,5371 

1902 

12,239 

1,079 

17,711 

3,054 

1903 

11,461 

2,868 

17,128 

2,595 

1904 

8,819 

1,238 

14,384 

18,417 

1905 

2 

188 

15,538 

5,550 

1906 

703 

83 

16,153 

1,728 

In  addition  to  the  foregoing,  Cefn  Coch  mines  for  the  years 
1901-1903  produced  90|  ounces  gold  from  58|  tons  ;  and  Ffridd 
Coch,  43  ounces  from  76 J  tons  during  1 90 1-1 902. a  Small  yields 
have  also  been  obtained  from  Borth  Valley  mines  (27  ounces), 
and  from  the  Arenig  mines,  Bala  (2  ounces). 

It  will  be  seen  that  at  times  the  returns  have  been  so  large  as 
to  admit  of  a  handsome  profit.  The  net  profit  of  the  St.  David's 
Gold  and  Copper  Mines,  Ltd.,  for  the  year  1900,  was  £39,729,  which 
admitted  of  the  payments  of  dividends  at  the  rate  of  60  per  cent,  on 
the  capital.  While  the  gross  receipts  for  that  year  were  £51,344. 
4s.  10d.,  the  total  expenses  were  only  £8,423.  9s.  7d.,  or  8s.  7|d., 
per  ton.  The  royalties  paid  to  the  Crown  were  £2,038.  7s.  7d.,  or  at 
the  rate  of  2s.  Id.  per  ton  of  ore  crushed.  The  extremely  low  mining 
and  milling  costs  have  therefore  permitted  of  the  payment  of  sub- 
stantial dividends. 

The  rocks  of  the  auriferous  area  of  North  Wales  may  be  grouped 

as  follows  : — 

Bala  Series Castell-carn-Dochan  Slates. 

Bala  Age     Felstone-porphyriesand  felspathic  ashes. 

Arenig  Age Igneous  intrusive  rocks. 

C  Dolgelly  Beds. 
Lingula-flag  Series  J  Ffestiniog  Beds. 

(  Maentwrog  Beds. 


Upper  Cambrian 
or  Ordovician 


Middle  Cambrian 


Lower  Cambrian 


Menevian  Series. 
Harlech  Series 


.Harlech  Grits. 


a  Home  Office  Rep.  Mines  and  Quarries,  1902.     Part  III. 


128  EUROPE. 

Neither  in  the  Harlech  grits  nor  in  the  Menevian  beds  are  metal- 
liferous veins  developed,  and  the  general  horizon  of  the  auriferous 
veins  of  North  Wales  is  that  of  the  Lingula-flags.  These  are  divided 
into  three  groups.  The  lowest,  the  Maentwrog,  rests  in  this  area 
directly  and  without  unconformity  on  the  Menevian  beds,  and 
like  them,  dips  south-east  and  east  at  angles  varying  from  45° 
near  Barmouth  to  10°  near  Gwyn-fynydd.  They  are  f ossi- 
ferous at  Tyddyn-gwladys  and  Cwm  Eisen.  The  most  productive 
auriferous  lodes  in  these  beds  include  the  Gwyn-fynydd,  Cwm 
Eisen,  Cefn-dewddwr,  Ganllwyd,  Berthllwyd,  Cefn  Coch,  Voel,  and 
Clogau.  The  contact  of  the  Maentwrog  and  the  underlying 
Menevian  beds  is,  especially  in  the  Llechau  and  Mynach  valleys, 
clearly  traceable  on  the  surface,  the  Menevian  beds  showing  a  barren 
surface,  while  the  slates  of  the  Maentwrog  beds  yield  a  fair  soil  that 
supports  an  abundant  vegetation.  The  rocks  of  the  Maentwrog 
beds  are,  on  the  whole,  grey  and  dark-coloured  slates,  sometimes 
highly  ferruginous,  associated  with  occasional  bands  of  sandstone. 

The  Ffestiniog  beds,  which  conformably  overlie  the  Maentwrog 
beds,  are  developed  from  Moel-Hafod-Owen  through  Glasdir  to 
Penmaenpool.  The  auriferous  veins  on  this  horizon  are  those  at 
Dol-y-frwynog  and  at  Glasdir.  The  Ffestiniog  beds  in  this  neigh- 
bourhood have  been  very  considerably  altered  by  dynamic  stress, 
occasioned  possibly  by  the  extrusion  of  the  great  neighbouring 
igneous  mass  of  Rhobell  Fawr.  The  ordinary  slaty  rocks  of  the 
Lingula-flags  give  place  to  a  hard,  massive  rock,  indistinguishable 
in  many  cases  froni  the  intrusive  felspathic  igneous  rocks  of  the 
area.  In  places,  it  contains  a  large  quantity  of  talc,  becoming  a 
talcose  schist,  weathering  along  fissure-planes  to  a  somewhat  kaolinic 
clay. 

Igneous  rocks  are  well  developed  in  the  auriferous  area,  the 
intrusions,  especially  north  of  the  Mawddach  river,  between  the 
Barmouth  estuary  and  Llanelltyd,  running  parallel  with  the  strike 
of  the  lower  beds  of  the  Lingula-flag  series.  They  occasionally 
occupy  fault-lines,  furnishing  a  remarkable  instance  midway  between 
Tyn-y-groes  and  the  Clogau  mine,  where  the  large  Cefn  Coch 
quartz-lode  occupies  for  some  distance  the  plane  of  contact  between 
the  Menevian  and  Maentwrog  beds ;  further  south-west,  the 
fissure,  which  runs  into  the  head  of  the  Mynach  valley,  has  been 
filled  by  intrusive  diabase,  which  at  times  again  gives  place  to 
quartz.  No  less  than  150  diabasic  intrusions,  varying  from  a  few 
feet  to  nearly  a  mile  in  length,  have  been  mapped  in  this  area  by  the 
officers  of  the  Geological  Survey.  Many  of  the  dyke-rocks  are  light 
in  colour,  and  exhibit  the  imperfect  crystallization  due  to  rapid 
cooling.     Some  are  calcareous,  showing  effervescence  on  treatment 


WALES.  129 

with  acid.    They  are,  as  far  as  may  be  gathered  from  hand  specimens, 
dolerites  and  diabases. 

These  North  Wales  gold  mines  are,  with  the  exception  of  Castell- 
carn-Dochan,  disposed  along  the  northern  and  western  slopes  of 
the  watershed  of  the  Afon  Mawddach,  a  stream  flowing  into  St. 
George's  Channel.  The  auriferous  belt  extends  from  near  Pontddu, 
midway  between  Barmouth  and  Dolgelly,  in  an  easterly 
direction  to  a  mile  beyond  the  falls  at  Rhaiddr  Mawddach. 
The  two  most  productive  lodes  are  located  one  at  each  end  of 
the  already  proved  auriferous  belt — the  Clogau  on  the  south-west 
and  the  Gwyn-fynydd  on  the  north-east.  The  Clogau  mine  is 
situated  some  distance  from  Pontddu  up  the  Cwm-llechau  valley. 
Midway  between  Pontddu  and  the  mine  is  the  crushing-mill,  the  ore 
being  conveyed  by  an  aerial  tramway  from  the  mouth  of  the  main 
level.  The  mountainous  nature  of  the  country  permits  of  the  lode 
being  worked  level-free,  and  at  the  same  time  furnishes  abundant  fall 
for  the  use  of  the  water  of  the  Llechau  as  a  source  of  motive-power. 
The  St.  David's  lode  lies,  as  already  stated,  in  the  Middle  Cambrian 
slaty  rocks  (Lingula-flags),  a  short  distance  south  of  their  line  of 
surface-contact  with  the  coarse  greenish-grey  underlying  Lower 
Cambrian  or  Menevian  grits  and  sandstones.  The  vein,  which  has 
a  nearly  east  and  west  strike,  parallel  with  the  line  of  contact  men- 
tioned, is  almost  perpendicular,  any  dip  being  towards  the  north. 
It  varies  in  width  from  2  to  9  feet,  but  it  is  much  split  in  places, 
forming  occasionally  large  horses.  The  matrix  of  the  vein  is 
quartz,  somewhat  white  and  chalcedonic  in  appearance,  especially 
near  and  at  the  surface.  Calcite  is  not  uncommon,  and  occasionally 
contains  gold.  Of  the  sulphide  ores  found  at  depth,  blende  is  by 
far  the  most  abundant,  but  iron  pyrites,  pyrrhotite,  chalcopyrite, 
and  arsenopyrite  also  occur  in  quantity.  Tetradymite,  the  silvery 
white  telluride  of  bismuth,  and  a  somewhat  uncommon  associate 
of  gold,  is  met  with  at  Clogau.  The  gold  itself  is  occasionally 
in  the  clean  white  quartz,  where  it  is  shotty,  but  is  more  often  asso- 
ciated with  blende  or  with  a  darker  veinstone,  the  darker  hue  being 
probably  due  to  the  contemporaneous  deposition  of  sulphides  in  a 
state  of  extremely  fine  division.  The  values  are  disposed  generally 
in  shoots  and  pockets. 

The  Gwyn  -  fynydd  mine  lies  a  short  distance  above 
Rhaiddr  Mawddach ;  like  the  Clogau  it  has  the  advantage  of 
an  ample  supply  of  water  under  a  good  head,  and  also  is  worked 
level-free.  This  mine  was  originally  opened  as  a  lead  mine,  but  in 
1870  a  small  rich  pocket  of  gold-ore  was  discovered  a  few  feet  below 
the  surface,  portions  yielding  at  the  rate  of  7  to  16  ounces  to  the 
ton.     The  auriferous  character  of  the  lode  was  first  discovered  in 


130  EUROPE. 

1864.  The  Gwyn-fynydd  lode,  like  the  St.  David's,  from  which  it  is 
distant  about  8  miles,  is  close  to  the  contact  between  the  Maentwrog 
slates  and  the  Menevian  sandstones.  The  former,  in  this  area,  dip 
to  the  east  at  angles  varying  from  10°  to  60°.  The  latter 
also  dip  in  the  same  direction,  but  at  much  lower  angles. 
The  lode  strikes  east  and  west,  dipping  to  the  north 
at  about  80°.  It  branches  in  several  places,  forming  numerous 
small  horses  of  slate.  As  a  natural  consequence,  its  width 
varies  considerably,  2  feet  and  20  feet  being  perhaps  the 
extreme  limits.  The  matrix  of  the  gold  is  a  white  and  opaque 
quartz.  In  places  it  is  much  mineralised,  the  most  abundant 
sulphide  being  blende  ;  but  pyrite,  mispickel,  galena,  and  chalco- 
pyrite  are  also  present.  The  gold  here  is,  as  a  rule,  much  finer  in 
grain  than  that  from  Clogau  ;  indeed,  in  some  cases,  it  is 
so  finely  divided  that  it  imparts  a  yellow  stain  to  the  stone, 
with  which  it  is  obviously  of  contemporaneous  origin.  In  other 
cases,  the  gold  is  of  subsequent  deposition,  occurring  in  vughs  in 
blende,  and  infiltrating  the  somewhat  cavernous  quartz.  In  the 
latter  case,  the  gold  is  often  leaflike  and  wiry.  Since  the  discovery, 
in  1888,  of  the  rich  shoot,  which  has  been  traced  for  more  than 
300  feet,  this  lode  has  yielded  consistently,  and  for  many  years  it 
furnished  the  greater  proportion  of  the  Welsh  gold-yield. 

In  the  vicinity  of  Gwyn-fynydd,  mines  that  have  yielded  good 
specimens,  but  have  never  been  sufficiently  rich  in  gold  to  pay  for 
working  expenses,  are  the  Cwm  Eisen  (Cwm-heisian),  Dol-y- 
frwynog,  Cefn-dewddwr,  and  Tyddyn-gwladys.  Of  these,  as  we 
have  already  seen,  Cwm  Eisen  and  Dol-y-frwynog,  were  among 
the  earliest  worked,  and  though  never  yielding  a  profit, 
the  gold  produced  from  them  has  been  considerable.  Cwm 
Eisen,  in  the  early  days  of  gold  mining,  yielded  two  large 
returns,  of  170  ounces  from  300  tons  and  148  ounces  from  157i  tons 
respectively.  The  quartz  is  on  the  whole  rather  clear,  and  the  in- 
variable associate  of  the  gold  is  zinc-blende,  the  latter  being  some- 
times contemporaneous  and  sometimes  prior  in  point  of  deposition. 
Galena  and  pyrites  also  occur  in  quantity. 

The  Dol-y-frwynog  mine,  about  a  mile  east  of  Cwm  Eisen,  has 
produced  some  very  rich  ore.  The  gold  here  is  fine,  at  times 
staining  the  quartz.  It  is  also  found  associated  with  blende  and 
with  pyrites.  The  main  lode  averages  about  5  feet  in  width,  strikes 
west-north-west  and  east-south-east,  and  dips  towards  the  north 
at  about  40°.  At  a  depth  of  200  feet,  very  rich  ore  was  met  with 
in  this  mine.  The  Tyddyn-gwladys  silver-lead  mine  has  yielded  a 
small  quantity  of  gold,  as  also  has  the  Cefn-dewddwr.  Both  are 
situated  almost  at  the  junction  of  the  Menevian  and  the  Maentwrog 
beds. 


WALES.  131 

On  the  west  of  the  river  Mawddach,  below  its  junction  with 
the  river  Eden,  gold  has  been  obtained  in  small  quantities  from 
lodes  at  Ganllwyd,  Coed-cy-fair,  Berthllwyd,  Goitref,  Cae-gwernog, 
Cefn  Coch,  and  Cae-mawr.  These  are  either  in  the  Maentwrog 
beds  or,  as  in  the  case  of  Cefn  Coch,  are  at  the  contact  with  the 
underlying  Menevian  beds.  East  of  the  Mawddach,  and  across  the 
valley  from  the  foregoing  are  Penrhos,  Tyn-y-Penrhos,  and  Glasdir. 
The  last  is  situated  opposite  the  Tyn-y-Groes  hotel,  and  a  short 
distance  up  the  Afon  Pabi.  The  country  here  is  of  bedded 
slate  (Festiniog  beds)  striking  about  north-east  and  south-west, 
and  dipping  south-eastward.  The  ore-body  is  not  a  defined  vein, 
but  appears  to  be  an  impregnation  of  the  country-rock  along  a  line 
of  faulting,  and  is  contained  between  two  fairly  well-defined  walls, 
which  are  usually  slickensided.  The  auriferous  pyrites  (pyrite  and 
chalcopyrite)  is  distributed  in  irregular  patches  throughout  the  ore- 
body.  The  general  tenor  of  the  ore-body  is  about  1  ■  1  per  cent,  of 
copper,  with  a  very  small  proportion  of  gold,  less  than  1  ounce  per 
ton  of  concentrates. 

The  only  other  lodes  to  be  noted  in  this  area  are  those  included 
in  the  Voel  mines  near  Llanelltyd,  where  they  occupy  planes 
of  contact  between  diabase  and  slates,  the  igneous  rock  in 
one  case  forming  the  hanging- wall  and  the  slates  the  foot- wall  of 
the  vein.  The  auriferous  quartz  is  generally  stained  with  green 
chloritic  matter,  and  is  associated  with  zinc-blende,  here  the  usual 
"  indicator  "  for  gold.  The  gold  is  sometimes  contained  in  the 
quartz,  but  is  more  often  deposited  on  the  accompanying  blende. 

The  only  noteworthy  auriferous  occurrence  outside  the  watershed 
of  the  river  Mawddach  is  that  of  Castell-carn-Dochan,  about  five  miles 
from  Bala,  and  two  miles  from  the  small  village  of  Llanuwchllyn. 
The  main  auriferous  vein  strikes  north-east  and  south-west,  dips 
southward,  and  is  composed  of  extremely  clean  quartz,  completely 
free,  as  a  rule,  from  sulphide  ores.  The*  gold  occurs  in  specks 
disseminated  throughout  the  quartz.  The  lodes  are  in  soft,  black, 
shaly  rocks,  dipping  eastward  at  about  45°,  very  near  their 
junction  with  the  felspathic  ash-beds  and  lavas  which  form  the 
summit  of  Castell-carn-Dochan.  Complete  reduction  works  were 
erected  in  1864,  and  up  to  the  end  of  1865  about  3,500  tons  had 
been  treated  for  a  yield  of  1,606  ounces.  The  lode  has  since 
been  worked  spasmodically,  in  1889  yielding  12 \  ounces  from  50 
tons,  and,  during  the  years  1895  to  1898  inclusive,  393  ounces  of 
gold  from  2,638  tons  crushed. 

The  gold  or  electrum  of  the  Welsh  auriferous  region,  when  met 
with  in  situ,  is  scattered  throughout  the  quartz  matrix,  or  occurs 
deposited  on  blende  or  pyrites  in  vughs  and  cavities.     It  rarely 


132  EUROPE. 

shows  any  approach  to  crystallization.     The  following  are  average 
percentage  analyses  of  vein  gold  from  Clogau  : — 


No.  of 
Sample. 

Gold. 

Silver. 

Quartz. 

Loss. 

1 

2 

90-16 

89-83 

9-26 
.         9-24 

0-32 
0-74 

0-26 
0-19 

These  samples  represent  a  value  of  £3.  16s.  to  £3.  16s.  6d.   per 
ounce. 

The  alluvial  gold  of  the  river  Mawddach  is  found  mainly  in  the 
bed  of  the  stream,  but  a  fair  prospect  may  be  washed  in  many 
places  from  the  soil  on  the  slopes  of  the  valley.  The  gold  occurs  in 
small  flattened  grains,  often  coated  with  a  haematitic  film,  and  is 
associated  with  galena,  blende,  titanic  iron  ore,  marcasite,  and  pyrite. 
Its  specific  gravity  is  low,  namely,  15*  79,  due,  however,  not  so  much 
to  impurities  as  to  the  presence  of  numerous  small  air  cavities.  As 
a  general  rule,  the  Mawddach  alluvial  gold  is  worth  about  5s.  per 
ounce  more  than  vein  gold.  It  is  also  lighter  in  colour  than  the 
Clogau  gold,  owing  to  the  admixture,  in  the  latter,  of  copper  with 
the  ordinarily  prevailing  silver. 

The  earliest  recorded  attempt  to  obtain  gold  from  the  sands  of 
the  river  Mawddach  was  that  of  Mr.  Frederick  Walpole  and  Sir 
Augustus  Webster,  who  obtained  an  appreciable  quantity  in  the 
summer  of  1852.  In  1870,  owing  to  the  unprecedented  lowness  of 
the  river  Mawddach,  several  Australians  and  Californians  worked 
its  bed  with  good  results.  One  sample  of  about  1  ounce  weight 
was  taken  to  Liverpool  and  there  assayed  at  the  rate  of  23  §  carats 
(nearly  990  fine).  Above  Gwyn-fynydd  no  nuggets  have  been  found, 
but  they  occur  along  the  whole  course  of  the  river  Mawddach  from 
Rhaiddr  Mawddach  to  Cymmer  Abbey,  the  gold  gradually  becoming 
finer  as  the  latter  place  is  approached. 

An  analysis  of  the  alluvial  gold  of  the  river  Mawddach  made 
by  Forbes  gave  the  following  results  : — 


Gold. 

Silver. 

in  in. 

Quartz.  . 

Loss. 

Specific 

Gravity. 

84- 8D     . 

.     13-99     . 

.     0-34     . 

.     0-43     . 

.     0-35     . 

.     15-79 

It  will  be  noted  that  this  analysis  shows  a  much  lower  value 
than  those  of  the  vein  gold  from  Clogau  cited  above.  This  is  due 
to  the  fact  that  none  of  the  alluvial  gold  of  the  river  Mawddach  is 
derived  from  the  Clogau  lode,  but  in  all  probability  arises  from  the 
degradation  of  the  Gwyn-fynydd  or  neighbouring  lodes,  the  gold  of 
which  is  worth  much  less  than  that  from  Clogau,  8  miles  to  the 
south-east.  A  fruitless  attempt  has  in  recent  years  been  made  to 
dredge  the  gravels  of  the  Mawddach. 


133 


SCOTLAND. 

The  earliest  recorded  notice  of  the  occurrence  of  gold  in  Scotland 
is  found  in  a  grant  (1153  a.d.)  to  the  Abbey  of  Dunfermline  of  a 
tithe  of  all  the  gold  which  should  accrue  to  David  I  from  Fife  and 
Fothrif ,  and  Gilbert  de  Moravia  is  said  to  have  discovered  gold  at 
Duriness  (Durness),  in  the  north-west  of  Sutherland,  in  1245. 

With  the  discovery  of  the  gold  mines  of  Crawford  Moor  in  the 
reign  of  James  IV  (1488  to  1513),  we  pass,  however,  from  the  region 
of  speculation  to  that  of  fact,  for  in  the  Treasurer's  accounts  for 
1511,  1512,  and  1513,  are  found  many  payments  to  Sir  James 
Pettigrew  for  working  the  gold  mines  of  that  region.  In  1524,  it 
was  enacted  that  the  gold  from  Crawford  Moor  should  be  minted 
at  the  Cunyie  House  (the  Scottish  Mint).  The  Albany  medal, 
struck  in  the  same  year,  was  made  from  gold  found  on  Crawford 
Moor,  as  no  doubt  was  much  of  the  coinage  of  that  period. 

In  July,  1526,  a  lease  of  all  the  mines  of  gold,  silver,  and  other 
metals  was  granted  for  43  years  to  certain  Germans  and  Dutchmen, 
Joachim  Hochstetter,  Gerard  Sterk,  Antony  de  Nikets,  and  others. 
To  the  same  grantees,  a  license  to  coin  was  issued  in  the  following 
year.  But  the  results  could  not  have  been  encouraging,  for  in  1531 
a  payment  is  recorded  to  "  the  Dutchmen  quhill  cam  here  for  the 
myndis,  at  their  departing  hamewart."  In  1535,  a  commission  was 
appointed  to  enquire  into  the  workings  of  the  gold  mines,  with  the 
result  that  miners  were  imported  from  Lorraine  in  1539.  From 
1570  to  1583  licenses  to  work  the  gold  mines  of  Scotland  were 
successively  assigned  to  Arnold  von  Bronchhorst,  to  Abraham 
Peterson  (or  Greybeard),  and  to  Eustachius  Roche  (1583).  The 
royalty  demanded  varied  from  6  to  7  ounces  per  100  ounces 
obtained,  and  the  remainder  was  to  be  brought  to  the  Cunyie 
House,  where  £22  Scots  was  paid  for  the  ounce  of  fine  gold 
and  40  shillings  Scots  for  the  ounce  of  fine  silver.  About 
1578,  there  appeared  on  the  scene  one  Sir  Bevis  Bulmer,  a  man 
destined  to  play  a  great  part  in  the  development  and  working 
of  the  Crawford  Moor  deposits.  The  scenes  of  his  operations  lay 
principally  on  Mannock  Moor  and  Wanlock  Water  in  Nithsdale, 
and  on  Friar's  Moor  and  Crawford  Moor,  and  the  district  in 
the  Leadhills.  He  worked  the  deposits  very  systematically, 
constructing  head-races  and  tail-races,  and  appears  to  have  been 
fairly  successful.  The  largest  nuggets  of  pure  gold  recorded  by 
him  are  of  6  ounces  and  5  ounces  weight  respectively.  They  were 
found  within  2  feet  of  the  moss  at  Lang  Cleuch  Head. 

In  1593,  James  VI  granted  the  gold  mines  of  Glengonnar 
to    Thomas  Foullis,   a    goldsmith,   and  a  burgess    of    Edinburgh. 


134  EUROPE. 

In  1603,  a  sum  of  £200  was  granted  to  Sir  Bevis  Bulmer,  and  in 
1604,  £300  to  George  Bowes,  to  search  for  gold  and  other  metals 
on  Crawford  Moor.  Bowes  reported  the  discovery  of  an  auriferous 
vein,  but  later  was  doubtful  of  it  being  so.  He  gave  up  his  work  in 
1604.  After  Bowes's  retirement,  little  appears  to  have  been  done  till 
1616,  when  a  grant  of  the  Scottish  mines  was  made  to  Stephen 
Atkinson,  an  Englishman  and  a  refiner  in  the  Mint  of  the  Tower  of 
London.  The  operations  were  apparently  unsuccessful,  for  in 
1621  a  lease  was  granted  to  John  Hendlie,  physician,  for  a  period  of 
21  years,  and  another  in  1631,  for  7  years,  to  James,  Marquis  of 
Hamilton.  In  1649,  grants  are  recorded  in  favour  of  Sir  James 
Hope  in  respect  of  the  Crawford  Moor  mines. 

At  the  present  time,  it  is,  of  course,  impossible  to  estimate  with 
any  approach  to  accuracy  the  quantity  of  gold  yielded  by  the 
Crawford  Moor  placer  deposits  during  the  sixteenth  and  seventeenth 
centuries.  Pennant,  on  what  authority  it  does  not  appear,  says, 
"  In  the  reigns  of  James  IV  and  James  V,  vast  wealth  was  pro- 
cured in  the  Leadhills,  from  the  gold  found  in  the  sands  washed  from 
the  mountains  ;  in  the  reign  of  the  latter  not  less  than  £300,000 
sterling."  Dr.  Lauder  Lindsay  places  the  yield  still  higher, 
namely,  £500,000,  but  his  authorities  for  this  high  sum  are  equally 
obscure.  Bowes  himself,  speaking  of  the  total  produce  of  the 
Crawford  Moor  district,  during  his  own  and  part  of  the  preceding 
generation,  places  the  yield  at  £100,000  sterling,  and  even  this 
amount  is  probably  overstating  rather  than  understating  the 
amount. 

Lanarkshire. — The  district  of  Leadhills,  southern  Lanarkshire, 
lies  about  44  miles  south-east  by  south  from  Glasgow.  The 
auriferous  area  lies  almost  entirely  in  rocks  of  Lower 
Silurian  age — of  Llandovery,  Caradoc-Llandeilo,  and  Arenig  time. 
The  surface-contact  line  of  the  Llandovery  and  the  older  underlying 
Caradoc-Llandeilo  beds  runs  approximately  north-east  and  south- 
west, parallel  with,  and  some  little  distance  to  the  north  of  the 
Potrail  Water. 

The  oldest  rocks  in  the  district  are  pillowy  diabase-lavas  which, 
with  the  overlying  radiolarian  cherts,  are  exposed  in  rapidly- 
recurring  folds  wherever  denudation  has  proceeded  sufficiently  far 
to  remove  the  younger  rocks.  The  folds  are  generally  isoclinal. 
and  relief  is  often  obtained  by  the  development  of  thrust-planes . 
Overlying  the  radiolarian  chert  (Lower  Llandeilo)  is  a  well-defined 
but  thin  band  of  black  shale — the  Glenkiln  shales  (Upper  Llandeilo). 
Overlying  the  Glenkiln  shales,  at  a  short  interval,  and  without  any 
stratigraphical  break,  are  the  Hartfell  shales  (Caradoc),  which  at 
the  Leadhills  occasionally  give  place  to  coarse  grey-wackes,  grits, 


SCOTLAND.  135 

and  conglomerates.  It  is  in  these  arenaceous  sediments  alone  that 
the  metalliferous  (galena)  veins  of  the  Leadhills  are  developed.  As 
these  veins  approach  the  black  shales,  either  laterally  or  in  depth, 
they  gradually  become  poorer,  and  finally,  with  contact,  the  galena 
disappears  from  the  vein. 

The  gold  of  the  Leadhills  area  is  found  in  the  streams,  into 
which  it  has  been  washed  from  a  gravelly  clay,  locally  known 
as  "  till,"  which  lies  on  the  slopes  of  the  hills.  It  generally 
occurs  as  fine  dust,  but  small  nuggets  have  from  time  to  time  been 
observed.  The  largest  on  record  weighed  27  ounces  ;  it  is  said  to 
have  been  discovered  about  1502,  and,  being  larger  than  the 
Wicklow  nugget  of  22  ounces,  is  therefore  the  heaviest  recorded 
British  nugget.  Gold-washing  as  an  industry  has  been 
abandoned  at  Leadhills  for  many  years,  such  gold  as  has  been 
obtained  during  the  last  century  having  been  collected  for  the 
purpose  of  making  jewellery  for  wedding-presents,  &c,  to  the 
ground  landlords.  The  gold  from  Wanlockhead  is  of  the  average 
quality  of  British  gold,  the  following  being  an  assay :  Gold, 
86-60;  silver,  12-39;  copper  and  iron,  0*35;  loss,  0*66.  The 
specific  gravity  is  16-50. 

Gold  has  also  been  found  in  situ  in  the  Leadhills  district. 
In  1803,  Prof.  Traill  recorded  gold  from  a  vein  of  quartz  at 
Wanlockhead,  and  in  the  Edinburgh  Museum  of  Science  and 
Art  there  is  a  specimen  of  clean,  slightly  water-worn,  white 
quartz,  containing  gold  which  shows  a  tendency  to  wiriness. 
A  specimen  of  auriferous  quartz  in  the  Edinburgh  Museum  of 
Science  and  Art,  from  Wingate  burn,  Leadhills,  shows  somewhat 
wiry  gold,  is  but  little  water-worn,  and  is  associated  with  a  clean, 
milky- white  quartz.  Another  specimen  from  Stake  burn,  Wan- 
lockhead, in  the  same  museum,  shows  native  gold  disseminated 
throughout  limonite  and  quartz. 

Sutherland. — Though,  as  far  back  as  1853,  a  nugget  weighing 
1|  ounces  is  recorded  as  having  been  picked  up  in  1840  in  the  Kil- 
donan  stream,  and  though,  as  we  have  already  seen,  gold  was  repu- 
ted to  have  been  obtained  in  1 245  by  Gilbert  de  Moravia  at  Durness 
(a  few  miles  south-east  of  Cape  Wrath),  it  was  not  known  to  occur 
in  any  considerable  quantity  in  Sutherland  until  November,  1868, 
when  the  re-discovery  of  gold  was  made  in  Kildonan  burn,  a  small 
tributary  of  the  Ullie.  Following  up  the  discovery,  gold  was  found 
in  the  neighbouring  burns,  and  a  rush  to  the  neighbourhood  took 
place.  At  one  time,  in  1869,  no  less  than  400  men  were  employed 
at  the  diggings.  That  the  work  was  remunerative  for  the  time 
being,  is  evidenced  by  the  continued  payment  during  a  year  of 
the  license-fee   for  each  digger  of   £1   per   month,   in  addition  to 


136  EUROPE. 

the  royalty  of  10  per  cent,  demanded  by  the  Government. 
During  the  short  period  that  these  gravels  were  worked  after 
the  discovery  of  their  auriferous  character,  royalty  was  paid  on 
£3,000  worth  of  gold  ;  but  as  the  temptation  to  conceal  the  greater 
portion  of  the  gold  discovered  must  have  been  almost  irresistible,  it 
is  possible,  as  estimated  by  Dr.  Joass,  that  the  total  amount 
recovered  was  not  less  than  £12,000. 

About  the  same  time,  gold  was  discovered,  but  in  smaller 
quantities,  in  the  Allt-Smeoral,  or  Gordon-bush  burn,  and  in  the 
Uisge  Duibh  or  Blackwater,  two  streams  falling  into  the  head  of 
Loch  Brora.  These  were,  however,  worked  for  a  very  short  time, 
since  the  license-fees  obtained  did  not  by  any  means  compensate 
for  the  damage  occasioned  by  the  diggers  to  pastoral  interests  by 
driving  sheep  away  from  the  sheltered  valley  to  the  bleak  moorland. 
Digging  was  therefore  prohibited  in  the  Brora  district  from  January 
1st,  1870,  and  has  never  since  been  resumed. 

The  goldfields  of  Sutherland  are  therefore  restricted  to 
two  main  localities — to  the  tributary  streams  flowing  from 
the  north  into  the  Ullie  or  Helmsdale,  and  to  the  two 
streams,  already  mentioned,  flowing  into  Loch  Brora.  All 
the  former  have  their  sources  in  the  highlands  running  along 
the  boundary  between  the  counties  of  Sutherland  and  Caithness. 
The  auriferous  streams,  are,  in  order  from  the  mouth  of  the  Helms- 
dale upward,  the  Allt  Torrish,  Allt  Breacich,  Allt  Duibh,  Kildonan, 
Allt  Ant'  Fionnaraidh,  Suisgill,  and  Kinbrace  (Cn  Preas).  The 
Craggie,  flowing  from  the  west  into  the  Ullie,  has  also  yielded  alluvial 
gold. 

The  whole  country  through  which  these  streams  run  is  typical 
moorland,  with  heather-clad  lower  hills  and  with  extensive  marshy 
ground  at  the  sources  of  the  streams  in  the  high  lands.  The  valleys 
of  the  streams  have  been  cut  down  rapidly,  and  are  narrow  and 
fairly  straight.  Alluvial  flats  of  any  size  are  wanting  along  their 
course,  and  it  is  only  in  the  main  stream,  the  Ullie  or  Helmsdale, 
that  such  are  developed. 

The  rocks  of  the  district  have  been  mapped  by  the  officers  of  the 
Geological  Survey,  and  are,  in  the  main,  granites  and  schists.  The 
auriferous  district  proper  is  almost  wholly  in  schistose  rocks, 
which  have  been  divided  into  quartz-schists,  flaser  mica-schists,  and 
granulitic  biotite-schists,  clearly  representing  original  sandstones 
and  shales,  probably  of  Lower  Silurian  age.  The  upper  portion  of 
the  Kildonan,  and  the  main  part  of  the  Suisgill,  lie  in  these  rocks. 
Overlying  the  metamorphic  schists,  and  rendering  it  at  all 
times  difficult,  and  in  some  cases  impossible,  to  map  out  the 
boundaries  of  the  rocks,  is  a  heavy  deposit  of  glacial  drift,  overlain 
in  its   turn  by  thick  beds  of  peat. 


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SCOTLAND.  [ ; J  — 

The  gold  is  found  as  small  grains  in  the  beds  of  the  streams. 
and  in  the  gravel  banks  along  their  courses.  It  is  naturally  most 
abundant  in  the  coarser  gravels,  and  in  the  crevices  afforded  by 
the  upturned  edges  of  the  flaggy  schists,  across  the  strike  of  which  the 
streams  run  ;  but  it  appears  to  be  also  disseminated  throughout 
the  drift.  Although  most  abundant  in  the  lower  courses  of  the 
streams,  it  is  not  found  there  alone,  but  occurs  in  the  heads 
of  the  burns,  clearly  demonstrating  either  long-continued  denuda- 
tion, or  more  probably,  a  concentration  of  the  gold  in  the  drift  which 
caps  all  but  the  highest  hills.  The  grains  of  gold  are  generally 
flattened,  and,  except  in  the  case  of  the  larger  nuggets,  present 
very  little  evidence  of  rolling  or  attrition  by  the  action  of  water. 
The  heaviest  nugget  discovered  here  weighed  2  ounces  17  dwts. 
Generally  speaking,  the  gold  becomes  finer  from  north-west  to 
south-east,  indicating  perhaps  a  north-western  origin  for  the  gold 
of  this  area.  The  alluvial  gold  of  Kinbrace  burn  is  coarse  and 
shotty,  as  also,  but  in  a  less  degree,  is  that  of  the  Suisgill,  while 
Kildonan  gold  farther  to  the  south-east  is  very  much  finer  than 
either  of  the  above.  The  richest  deposits  yet  found  have  been  in  the 
Gold  burn,  a  stream  flowing  from  the  east  into  the  Suisgill.  Here, 
indeed,  several  colours  or  specks  of  gold  may  be  obtained  from 
nearly  every  dish. 

The  matrix  of  the  gold  is  to  be  sought  for  in  the  quartz-veins  in 
the  local  schists,  and  possibly  in  similar  veins  in  the  granites  to  the 
north-west ;  but  in  the  latter  case  only  where  they  are  adjacent  to, 
or  intersect  the  schists.  An  examination  of  the  beds  of  the  streams 
disclosed  several  quartz-veins,  apparently  striking  and  dipping 
with  the  country. 

The  two  auriferous  localities  at  Loch  Brora  are  the  Allt  Smeoral, 
or  the  Gordon-bush  burn,  and  the  Uisge  Duibh,  or  Blackwater. 
The  former  flows  from  the  north  into  the  loch  about  f-mile  from  its 
head.  The  rocks  are  Lower  Silurian  flaggy  quartzites  and  mica- 
ceous schists  dipping  south-eastward  from  40°  to  60°.  Granite- 
dykes  and  quartz- veins  are  common  in  fhe  upper  waters  of  the  Allt 
Smeoral.  The  gold  is  found  in  the  bottom-stratum  of  coarse  grit 
lying  on  the  rock,  both  in  the  terraces  and  in  the  flats  of  the  stream, 
and  is  overlain  by  a  deposit  of  reddish  clay  and  sand,  much  of  which 
has  been  obviously  derived  from  the  neighbouring  Old  Red 
Sandstone  area. 

The  Uisge  Duibh,  or  Blackwater,  flows  into  the  head  of  Loch 
Brora,  in  the  upper  part  of  its  course,  over  Lower  Silurian  rocks 
precisely  similar  in  composition  to  those  noted  above,  and  through 
an  alluvial  flat  for  more  than  two  miles  of  its  lower  course.  A  short 
distance  above  its  junction  with  the  Brora  river,  two  miles  from  the 


138  EUROPE. 

Loch,  gold  has  been  found.  Here  the  burn  runs  across  the  strike 
of  the  rocks,  which  dip  south-eastward  at  angles  of  about  20". 
The  micaceous  schists  and  quartzites  are  seamed  by  numerous  narrow 
dykes  of  granite.  The  gold  occurs  in  a  bluish  sandy  clay,  together 
with  rolled  fragments  of  red  granite  and  quartz,  and  is  somewhat 
coarse  in  character.  There  is,  however,  little  alluvium  in  the  stream 
after  it  leaves  the  valley  plain  formed  by  the  filling  of  Loch  Brora. 

Other  Scottish  Occurrences. — The  other  Scottish  localities  in 
which  gold  has  been  discovered  may  be  grouped  into  two  divisions  : — 

(a).  Occurrences  which  may  be  associated  with  the  Leadhills 
alluvial  deposits.  These  are,  in  addition  to  the  streams  already 
mentioned  as  flowing  from  the  high  land  in  the  vicinity  of  Leadhills 
(Shortcleuch,  Leadburn,  Elvan,  Langcleuch,  Glengonnar,  Wanlock), 
those  in  valleys  flowing  into  the  Tweed  (Manor  Water,  Meggat. 
Yarrow,  and  Glengaber),  and  those  flowing  into  the  Annan  (Moffat 
Water  and  Dobbs  Linn).  All  the  above  occurrences  are  alluvial, 
but  auriferous  pyrites  is  recorded  from  Torbockhill,  near  Annan. 
This  on  analysis  yielded  4  dwts.  of  gold  and  10  ounces  of  silver 
per  ton.  The  auriferous  pyrites  was  taken  from  an  old  working 
called  "  the  cave,"  which  was  worked  in  the  eighteenth  century  by 
Germans. 

(b).  Perthshire  occurrences  (Breadalbane  area),  about  Loch  Tay 
and  the  headwaters  of  the  Tay.  According  to  Lauder  Lindsay,  a 
nugget  found  here  in  former  times  weighed  2  ounces.  He  also 
records  gold  in  its  matrix  from  Tyndrum,  at  the  head  of  Strathfillan, 
western  Perthshire,  where  argentiferous  galena  occurs  in  mica- 
slate  near  its  junction  with  quartzite.  In  1861,  James  Tennant 
found  gold  in  quartz,  associated  with  iron-pyrites  at  Taymouth. 
Gold  has  also  been  recorded  by  various  observers  from  other 
parts  of  Perthshire  :  from  galena  veins  at  Lochearnhead,  where 
arsenical  pyrites  has  yielded  at  the  rate  of  6  ounces  to  the  ton,  and 
where  particles  of  native  gold  have  been  found  in  the  gossan  ;  Glen 
Lednoch  ;  Ardvorlich,  south  side  of  Loch  Earn,  in  mining  for 
argentiferous  galena  ;  Cornebruchill,  on  the  southern  side  of  Loch 
Tay,  opposite  Ben  Lawers  ;  Glenturret  ;  Glenalmond  ;  and  Glen- 
quaich,  near  Loch  Freuchie.  There  is  in  the  British  Natural  History 
Museum  a  nugget  of  1,010  grains  from  Turrerich,  Glenquaich,  Bread- 
albane. It  is  of  a  brassy-yellow  colour,  and  is  apparently  of  very 
poor  quality.  It  contains  about  one-third  of  its  weight  of  quartz. 
The  gold  is  extremely  cavernous,  and  shows  a  tendency  to  crystalliza- 
tion, though  no  distinct  crystal-faces  are  to  be  seen. 

Small  quantities  of  alluvial  gold  have  been  recorded  from 
tributaries  of  the  Dee  at  Braemar  and  Invercauld,  and  in  the  sea- 
sand  of  the  coast  near  Aberdeen. 


SCOTLAND.  139 


In  1869,  gold-dust  in  small  quantity  was  found  in  the  alluvium 
of  the  headwaters  of  the  Erricht  and  Nairn  rivers  in  Inverness  ; 
gold  was  also  washed  from  the  granites  there  by  Dr.  Bryce  in  1870. 


IRELAND. 

There  is  no  actual  knowledge  of  the  discovery  or  working  of  gold- 
deposits  in  Ireland  before  1765.  Gerald  Boate,  in  his  Natural 
History  of  Ireland,  written  in  1652,  mentions  the  occurrence  of 
alluvial  gold  in  the  Mayola  (Miola)  river,  which  flows  into  Lough 
Neagh  through  a  portion  of  Londonderry  county. 

It  would  appear  that  the  first  well-authenticated  discovery  of 
gold  in  Ireland  was  made  about  1765,  a  small  nugget  being  obtained 
in  the  Ballinvalley  brook,  which  flows  into  the  Aughrim 
river,  near  its  junction  with  the  Ovoca.  Five  years  later  another 
small  nugget  was  found  in  the  same  stream  by  a  boy  while  fishing, 
but  it  was  not  until  September,  1795,  that  it  became  generally 
known  that  the  gravels  of  this  stream  (then  called  the  Aughatina- 
vought,  but  afterwards  called  by  Mr.  Thomas  Weaver  the  Ballin- 
valley or  Gold-mine  river)  were  more  or  less  auriferous  throughout 
its  whole  course.  A  rush  to  the  spot  naturally  followed,  and  in  a 
very  short  time  a  great  concourse  of  peasants  were  engaged  in  the 
arduous  and  unaccustomed  work  of  gold-washing,  using  the  crudest 
of  appliances.  In  October,  1795,  when  the  news  of  the  discovery 
came  to  the  ears  of  the  authorities,  a  strong  force  of  Kildare  militia 
was  sent  to  turn  away  the  peasants,  who,  driven  from  Ballin- 
valley and  Ballinasiloge,  the  richest  spots  on  the  Aughatinavought, 
flocked  to  the  neighbouring  streams,  but  these  apparently  did  not 
prove  as  rich  as  that  first  exploited,  for  work  in  them  ceased  after 
a  time. 

Government  operations  were  conducted  on  these  gravels  until 
May,  1798,  when  the  works  were  destroyed  by  the  rebels,  and  the 
workings  were  deserted  for  more  than  two  years.  During  the  period 
of  working,  the  directors  had  obtained  555  ounces  17  dwts.  22J 
grains  of  gold,  valued  at  £2,146.  15s.  The  cost  was  £1,815.  16s.  5d., 
and  thus  the  produce  of  the  undertaking  defrayed  all  expenses, 
and  left  a  surplus  in  hand.  Streaming  operations,  carried  on 
in  1801  in  the  branches  of  the  Gold-mine  river  and  in  adjacent 
streams,  yielded  388  ounces  6  dwts.  16f  grains,  valued  at  £1,528. 
12s.  11  Jd.,  so  that  the  total  quantity  of  gold  recovered  by  the  Govern- 
ment operations  was  944  ounces  4  dwts.  15  grains,  of  the  value  of 
£3,675.  7s.  lljd.     The  workings  were  abandoned  in  1803. 

In  1840,  Messrs.  Crockford  &  Co.  obtained  the  rights  to  the 
auriferous  deposits  and  worked  them  energetically  for  a  period  of 


140  EUROPE. 

nearly  4  months,  during  which  time  they  obtained  no  less  than 
£1,800  worth  of  gold,  including  one  nugget  of  11  ounces  and  another 
of  4  ounces  12  dwts.  12  grains.  It  seems  curious  that,  notwith- 
standing this  apparently  profitable  return,  the  enterprise  should 
have  been  abandoned  so  quickly ;  and  further  that,  if  we  except 
more  or  less  surreptitious  working  by  the  peasants,  no  attempt 
was  made  to  recover  the  gold  of  the  Gold-mine  river  until  1862, 
when  the  Carysfort  Mining  Company  leased  the  gold-royalties. 
This  company  appears  to  have  devoted  its  attention  rather  to  the 
discovery  of  auriferous  veins  in  the  neighbourhood,  than  to  the 
working  of  the  stream  gravels  ;  but  its  operations  in  the  former 
respect  were  no  more  successful  than  were  those  of  Messrs.  King, 
Weaver,  and  Mills  in  the  early  years  of  the  century.  The  company 
ceased  active  work  in  1865,  having  obtained  only  £203.  5s.  worth 
of  gold.  Since  that  time,  with  the  exception  of  some  desultory 
streaming  by  Mr.  Acheson  from  1876  to  1879,  no  work  has  been 
done  on  these  gravels. 

The  total  yield  of  the  Ovoca  gravels  since  1795  is  estimated 
at  from  7,440  to  9,390  ounces,  of  a  value  between  £28,855  and 
£36,185  ;  but  the  estimated  amount  bulks  very  largely  in  these 
totals  and  the  amount  recovered  is  possibly  much  less  than  that 
stated.a 

Though,  so  far  as  is  yet  known,  no  other  auriferous  deposits  of 
economic  value  occur  in  Ireland,  the  presence  of  gold  has  been 
detected  in  various  places,  both*  in  veins  and  in  alluvial  sands. 
Under  the  latter  head  are  the  sands  of  the  Glendun  river,  county 
Antrim,  which  enters  the  sea  at  Cushendun,  and  flows  from  the 
flanks  of  Slieve-an-Orra  ;  the  sands  of  the  Dodder  river  above  Rath- 
f  arnham,  which  yielded  the  two  small  nuggets  picked  up  many  years 
ago  on  Stephen's  Green,  Dublin  ;  Balliscorney  Gap,  county  Dublin  ; 
and  the  "  black  sand  "  deposit  near  Greystones,  county  Wicklow. 
This  last  deposit  appears  to  have  resulted  from  the  concentration, 
by  wind  and  by  wave-action,  of  the  heavier  constituents  of  the 
drift-sands  that  are  here  exposed  on  the  beach.  It  extends  along 
the  beach  for  several  hundreds  of  feet  and  was,  when  examined, 
several  inches  in  thickness.  It  contained  21*5  per  cent,  of  magnetic 
material  (magnetite,  chromite,  and  ilmenite),  together  with  red  and 
brown  haematite,  iron  pyrites,  rutile,  cassiterite,  and  garnets.  On 
washing  and  panning  7^1bs.  of  black  sand,  37  colours  of  very  finely 
divided  gold  were  left  in  the  dish.  Indeed,  "  gold  was  found  in 
small  quantities  in  all  the  specimens  of  black  sand  taken  from  the 
beach."6 

a  Kinahan,  Jour.  Roy.  Geol.  Soc.  Ireland,  VI,  1882,  p.  147. 
h  Idem,  loc.  cit.,  p.  113. 


IRELAND.  141 

Gold  in  situ  has  also  been  reported  from  Bray  Head, 
county  Wicklow  ;  from  the  gossan  of  the  Dhurode  copper-lode, 
Carrigacat,  county  Cork  ;  and  from  the  pyrites  and  gossan  of  the 
mineral  lodes  in  the  Ballymurtagh,  Cronebane,  and  Connary 
mines  in  the  Vale  of  Ovoca,  several  miles  to  the  north  of 
the  Gold-mine  river.  The  pyrites-lodes  of  the  last-mentioned 
district  have  long  been  known  to  carry  a  small  quantity  of  gold. 

From  the  foregoing,  it  will  therefore  be  apparent  that  the 
only  Irish  occurrence  requiring  description  in  this  place  is  that 
of  the  Gold-mine  and  adjacent  valleys  in  Wicklow. 

The  Gold-mine  river  flows  into  the  Aughrim  river  at  Wooden- 
bridge,  immediately  above  the  junction  of  the  Aughrim  with  the 
Ovoca.  Its  sources  are  on  the  southern  and  eastern  slopes  of 
Croghan  Kinshelagh  mountain,  the  highest  eminence  in  the 
vicinity.  For  the  greater  part  of  its  course  it  flows  through 
a  miniature  ravine,  with  steep,  well-wooded  sides.  These 
narrow  trench-like  valleys  in  the  slaty  rocks  are  characteristic, 
not  only  of  the  tributary  streams,  but  also  of  the  main 
rivers — the  Aughrim  and  the  Ovoca.  About  f-mile  above  the 
confluence  of  the  Gold-mine  river  with  the  Aughrim,  the  former  is 
augmented  in  volume  by  the  Eastern  stream,  also  auriferous.  All 
the  other  auriferous  streams  lie  to  the  west  of  the  Gold-mine  river, 
and  are  tributaries  of  the  Aughrim.  They  are  the  Ballintemple,  a 
mile  above  Woodenbridge  ;  the  Clone  ;  and  the  Coolbawn,  which 
flows  also  from  the  slopes  of  Croghan  Kinshelagh,  but  to  the  north- 
west. Gold  in  small  quantities  has  also  been  reported  from  the 
Ballythomas  stream,  still  further  to  the  west. 

All  these  streams  run  through  an  area  of  Lower  Silurian  (or 
Cambro-Silurian)  grey,  green,  and  dark  slates,  sandy  shales,  and 
grits,  belonging  probably  both  to  the  Caradoc  and  to  the 
Llandeilo  beds.  They  have,  in  this  district,  a  general  north-east 
to  south-west  strike  and  a  dip  south-eastward  of  70°  to  80°.  To 
the  west  and  north-west  of  the  Gold-mines  river,  and  forming 
the  high  lands  of  the  Croghan  Kinshelagh  (1,987  feet),  Monateigue 
(1,892  feet),  and  Ballycoog  (1,169  feet)  hills,  occurs  a  great  develop- 
ment of  plutonic  and  volcanic  rocks.  Both  appear  at  the  surface 
with  outcrops  elongated  in  a  general  north-easterly  and  south- 
westerly direction.  The  plutonic  rocks  occur  as  narrow  dykes  or 
masses,  and  are  essentially  microgranites.  The  volcanic  rocks 
are  developed  farther  to  the  north-east  than  the  microgranites, 
but  preserve  in  the  outline  of  their  exposures  the  same  general 
north-east  to  south-west  elongation  noted  in  fehe  case  of  the 
microgranites.  They  are  mainly  epidiorites,  quartz-  and  augite- 
diorites,  and  dolerites. 


142 


EUROPE. 


The  gold  of  the  Croghan  Kinshelagh  area  is  in  all  cases  found  in 
the  gravels  in  the  beds  of  the  streams.  Since  the  river- valleys 
are,  in  Wicklow,  extremely  narrow  and  deep,  it  follows  that  concen- 
tration of  the  gravels  has  been  restricted,  at  any  rate,  since  the 
initiation  of  the  present  valley-system,  to  the  well-defined  lines 
represented  by  the  present  courses  of  the  streams. 

The  black  sand  associated  with  the  gold  is  composed  mainly 
of  magnetite,  ilmenite,  haematite  and  iron-pyrites,  but  cassiterite, 
galena,  wolfram,  molybdenite,  gold,  copper-pyrites,  and  oxides 
of  manganese  also  occur  in  the  sand.  The  gold  of  the  gravels  is 
generally  in  fine  grains,  presenting  evidences  of  considerable 
attrition,  especially  in  the  lower  portions  of  the  streams.  Mr. 
Thomas  Weaver,  however,  noted  gold  ;t  crystallized  in  octa- 
hedrons, and  also  in  elongated  garnet  dodecahedrons,"  and 
"  frosted ':  or  crystallized  gold  has  been  remarked  by  various 
observers  from  the  upper  portions  of  the  valleys. 

The  heaviest  nugget  found  in  Wicklow  was  picked  up  by  a 
party  of  peasants,  in  or  about  September,  1795,  and  weighed  22 
ounces.  Fifteen  other  nuggets  from  Wicklow,  ranging  in  weight 
from  4  ounces  8  dwts.  to  1  dwt.  4  grains,  are  on  record. 

The  following  are  various  assays  of  Wicklow  gold  : — 


No.  of 
Sample. 

1 
2 
3 
4 
5 


Gold. 

Silver. 

Iron. 

Copper. 

Silica. 

94-06 

5-94 

90-62 

7-82 

1-56 

92-32 

6-17 

0-78 

. . 

91-01 

8-85 

,   , 

•  • 

0-14 

89-00 

8-10 

2-10 

Trace 

Totals. 


100-00 
100-00 

99-27 
100-00 

99-20 


The  richest  deposit  appears  to  have  occurred  in  the  upper  course 
of  the  Western  auriferous  stream  (also  called  the  Ballinvalley  stream) 
about  |-mile  below  Ballinagore  bridge.  Here,  at  the  Red  Hole,  and 
for  some  1,200  feet  below,  the  most  remunerative  results  were 
obtained  by  the  peasants,  by  Messrs.  King,  Weaver,  and  Mills,  and 
by  all  later  workers.  At  Lyra,  the  junction  of  the  Eastern  and 
Western  streams,  a  rich  deposit  was  found  containing  much  coarse 
gold.  Below  Lyra,  and  as  far  as  Rostigah,  the  gravels  of  the  main 
stream  were  productive  ;  but  below  Rostigah,  they  became  too 
poor,  and  the  overburden  proved  too  heavy  to  work. 

The  Ballintemple  brook,  flowing  into  the  Aughrim  from  the 
north-western  flank  of  Croghan  Kinshelagh,  was  worked  by  Messrs. 
Crockford  and  Company,  and  subsequently  by  the  Carysfort 
Mining  Company,  in  both  cases  yielding  gold,  both  fine  and  coarse. 


IRELAND. 


143 


In  the  Coolbawn  stream,  flowing  northward  to  the  Aughrim  from 

Croghan  Kinshelagh,  Mr.  Thomas  Weaver  found  a  2  J-ounce  nugget 

the  largest  discovered  outside  the  Ballinvalley  stream. 

The  source  of  the  alluvial  gold  was  probably  in  the  immediate 
vicinity  of  Croghan  Kinshelagh,  the  present  auriferous  deposit 
representing  the  concentrates  of  a  pyritous  lode  that  has  suffered 
degradation.  For  this  view  some  corroboration  is  afforded  by  assays 
of  quartz  from  a  vein  8  inches  wide,  and  in  the  immediate  vicinity 
of  the  old  Government  workings,  that  assayed  at  the  rate  of  4  dwts. 
of  gold  to  the  ton. 

General. — In  reviewing  the  geological  distribution  of  the 
known  auriferous  veins  of  Great  Britain  (Merioneth,  Leadhills, 
&c),  the  most  striking  feature  is  their  more  or  less  intimate  con- 
nection with  the  diabasic  intrusions  of  the  older  palaeozoic  rocks. 
Further,  in  the  case  of  the  alluvial  auriferous  deposits  of 
Sutherland  and  Wicklow,  where  the  parent-veins  have  not  been 
located,  the  available  evidence  leads  to  the  inference  that  those 
veins  also  are,  or  have  been,  located  in  Lower  Silurian  areas,  with 
which  are  generally  associated  diabasic  igneous  rocks. a 

The  total  yield  of  gold  in  Great  Britain  and  Ireland  may,  with 
the  exception  of  that  from  the  Leadhills,  be  computed  with  sufficient 
approach  to  accuracy  to  give  a  considerable  degree  of  value  to  the 
estimation.  The  yield  for  each  country  has  already  been  dealt  with 
under  its  respective  heading,  and  the  total  is  as  follows  : — 

£ 
England  :  North  Molton  581 


Wales  :  since  1844 
Scotland  :  Leadhills 

Sutherland  (1868-1869) 
Ireland 


Total  to  1906 


417,183 

100,000 
3,000 

28,855 

£549,619 


PORTUGAL. 

The  auriferous  alluvial  gravels  of  Portugal  were  worked  succes- 
sively by  the  Phoenicians,  Romans,  and  Arabs.  The  richer  deposits 
were  in  all  probability  exhausted  long  before  the  Christian  era,  but 
nevertheless  sufficient  gold  remains  at  the  present  day  to  afford  a 
scanty  subsistence  to  a  few  washers.  The  gravels  lie  along  the  course 
of  the  Tagus  and  its  tributaries,  and  more  particularly  at  Santarem, 
Almeira,  Alvega,  and  Rosmaninhal.  The  Elga,  the  boundary  stream 
between  the  province  of  Beira  in  Portugal  and  Caceres  in  Spain,  is 

a  For  a  detailed  description  of  British  gold  occurrences,  together  with  a  complete 
bibliography,  see  Maclaren,  Trans.  Inst.  M.E.,  XXV,  1902-3,  pp.  435,  et  seq. 


144 


EUROPE. 


probably  the  most  productive.  Near  Monfortinlio,  a  small  village 
on  its  course,  the  auriferous  beds  are  from  12  to  18  feet  thick,  with 
a  pay-streak  of  from  H  to  6  feet  in  thickness.  The  overburden  is 
of  clay.  The  pay-streak  carries  gold  to  the  amount  of  from  a  few 
grains  to  2J  dwts.  per  metric  ton,  but  the  average  tenor  of  the  whole 
vertical  series  is  probably  not  more  than  7  grains  per  ton.rt 

In  Northern  Portugal,  in  the  Provinces  of  Minho  and  Traz-os- 
Montes,  quartz-antimonite  (stibnite)  veins  carry  gold  in  gneiss  and 
palaeozoic  slates,  near  granite  contacts.  The  principal  district 
lies  on  the  Lower  Douro  at  Vallongo,  about  six  miles  east-north-east 
of  Oporto.  This  district  is  some  42  miles  long  and  7  miles  wide. 
Its  gold-production  is  small,  being  little  more  than  a  kilo  (32-15 
ozs.)  per  annum. b 

The  important  antimony  deposits  of  the  Traz-os-Montes  carry, 
in  addition  to  stibnite,  auriferous  chalcopyrite  and  pyrite  in  a 
quartz  matrix.  The  outcrops  of  these  veins  furnished  to  the  ancients 
a  considerable  amount  of  free  gold,  liberated,  of  course,  by  the 
weathering  of  the  sulphides.  Auriferous  quartz,  generally  asso- 
ciated with  copper  and  iron  pyrites,  exists  in  the  districts  of 
Coimbra,  Evora,  Beja,  Foro,  and  Porto.  The  poor  chalcopyrite 
veins  of  La  Sierra  da  Caviera,  6  miles  south  of  Grandola,  itself 
south-east  of  Lisbon,  contain  1  to  3  dwts.  gold  and  1|  to  10  ounces 
silver  per  ton.c 

Marine  placers  are  said  to  occur  on  the  coast  near  Adica,  between 
the  mouth  of  the  Tagus  and  Cape  Espichel.^ 

The  following  table  shows  the  official  return  of  gold  from 
Portugal  during  recent  years6  : — 


a  Breidenbach,  Zeit.  fur  prakt.  Geol.,  1893,  p.  250. 

h  Aklburg,  Zeit.  fur  prakt.  Geol.,  XV,  1907,  p.  204. 

''  Min.  Jour.,  November  30,  1907. 

d  Leonkard,  Top.  Min.,  1843,  p.  245. 

e  Dipl.  and  Consular  Reports. 

J  It  is  not  clear  whether  tke  gold  obtained  from    antimony  concentrates  is  included 
in  these  figures. 


145 


SPAIN. 

Both  Straboa  and  Pliny6  give  detailed  accounts  of  the  ancient 
gold  washings  of  Spain,  the  latter  describing  with  great  particularity 
the  methods  of  undermining  the  rock  and  of  washing  off  the  surface 
soil  and  overburden  by  the  system  known  to  modern  placer  miners 
as  "  hushing  "  or  "  booming."  Incidentally  he  mentions  the 
haphazard  nature  of  ancient  mining  :  "  Nor  yet  even  then  are  they 
sure  of  gold,  nor  indeed  were  they  by  any  means  certain  that  there 
was  any  to  be  found  when  they  first  began  to  excavate,  it  being 
quite  sufficient  as  an  inducement  to  undergo  such  perils  and  to 
incur  such  vast  expense  to  entertain  the  hope  that  they  shall  obtain 
what  they  so  eagerly  desire."  Spain  was  the  richest  gold  country 
known  to  Pliny,  and  for  the  possession  of  its  placers  many  wars 
were  waged.  According  to  the  same  historian,  the  annual  yield  of 
Spanish  gold  was  20,000  pounds.  As  each  Roman  pound  was  equiva- 
lent to  perhaps  10  ounces  troy,  this  quantity  may  represent  200,000 
ounces  troy.  At  one  time  no  less  than  60,000  slaves  were  employed ; 
their  sufferings  were  paralleled  only  by  those  inflicted  many  centuries 
later  by  the  Spaniards  themselves  on  the  unfortunate  inhabitants 
of  the  New  World. 

In  the  northern  provinces  of  Asturias  and  Leon  the  remains  of 
the  Roman  workings  may  still  be  traced,  and  the  canals  or  races 
by  which  the  water  was  brought  to  command  the  gravels  are  still 
visible.  Some  idea  of  the  scale  on  which  these  workings  were 
performed  may  be  gained  from  the  fact  that  water  was  conducted 
to  the  alluvial  gravels  by  channels  aggregating  100  miles  in  length. 
These  deposits  appear  to  have  been  exhausted  before  the  commence- 
ment of  the  Christian  era  and  washing  therein  has  been  carried 
on  only  spasmodically  during  the  last  2,000  years. 

The  auriferous  occurrences  of  Spain  form  two  groups,  one  in  the 
north  in  the  provinces  of  Leon  and  Asturias,  and  the  other  in  the 
south  in  Granada.  The  northern  area  lies  along  the  flanks  of  the 
Cantabrian  Mountains  (Sierra  Cantabrica)  west  of  a  line  drawn  from 
the  town  of  Leon,  in  the  province  of  the  same  name,  to  Oveido,  in 
the  province  of  Asturias.  Its  westward  extension  is  marked  by  the 
western  boundaries  of  the  above-mentioned  provinces,  and  its 
southern  by  the  railway  line  connecting  Villafranca  and  Astorga. 
The  principal  auriferous  streams  of  the  region  are  the  Sil, 
Duerna,  and  Eria,  together  with  the  Burbia,  Ancares,  and  Qua, 
principal  tributaries  of  the  Sil.  The  auriferous  region  has  a 
total    length     north     and     south    of     some     80     miles,     and    is 

a  Lib.  II,  cap.  II,  par.  38. 
h  Lib.  XXXIII,  cap.  21. 

K 


146  EUROPE. 

40  miles  in  breadth.  The  rocks  of  the  Cantabrian  Moun- 
tains are  Palaeozoic  (Silurian)  slates  and  schists  much  intruded 
by  granite.  A  great  number  of  quartz  veins  occur  in  these  rocks  and 
are  obviously  the  source  of  the  alluvial  gold.  The  only  quartz 
mines  that  have  recently  been  worked  in  the  Leon  province  are 
those  in  the  ferruginous  mica-schist  of  Menival.  The  valuable 
deposits,  however,  appear  to  be  auriferous  gravels,  which  may 
occasionally,  when  developed  as  high-level  terraces,  attain  an  extra- 
ordinary thickness  (900  feet)  ;  their  average  thickness  may  be 
assumed  to  be  some  30  to  60  feet.  They  are  disposed  along  the 
streams  on  both  slopes  of  the  Sierra  Cantabrica,  but  are  best  developed 
in  the  Rio  Sil,  where  the  remains  of  the  aqueducts  of  the  Romans 
are  especially  numerous.  The  average  tenor  of  these  gravels, 
according  to  Breidenbach,a  who  made  numerous  assays  from 
Navalgas,  La  Pol,  Allanda,  Nieves,  Palacios-Sil,  Paramos-Sil, 
Cuevas-Sil,  and  Salientinos,  was  nearly  2  dwts.  (3  grammes)  per  ton ! 
None  of  the  gold-quartz  veins  yielded  results  higher  than  2  dwts. 
(3-22  grammes)  per  metric  ton,  and  the  majority  gave  only  some 
9  or  10  grains  to  the  metric  ton.  It  is  therefore  fairly  clear  that  the 
northern  Spanish  gold-quartz  veins  are  of  little  present  economic 
value,  and  that  the  Romans,  or  even  their  predecessors,  the  Phoeni- 
cians and  the  Carthaginians,  have  long  ago  exhausted  any  secondary 
enrichments  that  may  have  been  formed  at  their  outcrops.  Little 
information  is  available  as  to  the  tenor  of  the  placer  deposits, 
though  serious  attempts  have  from  time  to  time  been  made  to  work 
these.  In  1887  the  Rio  Sil  and  Leon  Mining  Company  operated 
on  the  Duerna  river.  They  found  the  beds  to  consist  essentially  of 
180  feet  of  poor  gravel  overlying  a  richer  pay-streak  that  rested 
on  bed-rock.  It  was  found  that  the  Romans  had  already  worked 
patches  of  the  pay-streak  by  stripping  the  over-burden  by  "booming." 
The  company  sank  several  trial  pits  to  bed-rock,  which  was  reached 
at  depths  of  from  16  to  28  feet,  of  which  9  to  16  feet  were  over- 
burden and  7  to  12  feet  were  pay-dirt. 

According  to  Jones h  the  average  yield  from  the  trial  pits  by 
panning  was  about  1 8  grains  per  ton.  A  nugget  weighing  26  grains 
was  obtained,  while  another  with  crushed  quartz  crystals  attached 
weighed  23  dwts.  13  grains.  The  company  ceased  work  owing  to 
uncertainty  of  tenure  and  to  claims  for  compensation  for  damage 
done  by  the  debris  that  was  swept  down  the  streams  from  the 
alluvial  workings.  The  cultivators  living  on  the  lower  reaches 
of  the  Rio  Sil  further  succeeded  in  obtaining  a  legal  injunction  against 
working.     Desultory  washing  is  carried  on  during  a  few  weeks  in  the 

a  Zeit.  fur  prakt.  Geol.,  I,  1893,  p.  IS. 
b  Trans.  Inst.  M.E.,  XX,  1900,  p.  427. 


SPAIN. 


147 


summer  by  local  washers,  who  use  the  batea.  Their  earnings  are, 
however,  insignificant,  ranging,  under  exceptionally  fortunate 
conditions,  from  5  to  10  pesetas  (4s.  to  8s.)  per  head  per  day.ft 

The  southern  auriferous  occurrences  of  Spain  lie  along  the  banks 
of  the  Darro  and  Genii  streams  on  the  northern  slopes  of  the  Sierra 
Nevada  in  Granada.  The  Sierra  Nevada  is  made  up  principally 
of  gneiss,  schists  (micaceous,  hornblendic,  and  chloritic),  and 
granulites.  The  gravels  are  Pliocene  or  Pleistocene  in  age,  and  are 
composed  of  coarse  gravel  containing  at  times  large  boulders.  Beds 
of  clay  are  often  interstratified  with  the  gravel.  All  the  rocks  repre- 
sented in  the  gravels  are  to  be  found  in  situ  in  the  Sierra  Nevada. 
Boulders  of  mica-schist  are  occasionally  met  with  containing  gold- 
quartz  veins.  A  tough,  highly  ferruginous  clay,  containing  much 
sericitic  mica,  was  largely  washed  for  gold  by  the  ancients.  Their 
workings  extended  to  more  than  1,000  feet  above  the  present  bed  of 
the  Genii.  The  tenor  of  the  Granada  deposits  varied  from  less  than 
a  grain  to  1\  grains  per  cubic  metre.  These  deposits  are  interesting 
as  furnishing  the  only  example  of  modern  "  hydraulicing  "  that  has 
been  practised  on  a  large  scale  in  Europe.  The  head-race  is  nearly 
11  miles  (16  km.)  long,  of  which  more  than  4  miles  are  run  through 
tunnels.  The  available  head  thus  gained  was  about  550  feet. 
On  the  way  to  the  point  of  attack,  the  water  was  carried  across  a 
valley  by  an  iron  pipe-siphon  25  inches  in  diameter  and  2,600  feet 
long.  No  details  are  available  as  to  the  results  from  this  hydraulic 
installation. h 

The  following  table  shows  the  amount  of  gold  obtained  in 
Spain  during  recent  years  : — c 


Metric  Tons. 

Pesetas. 

Sterling. 

1900 

1,300 

39,000 

£1,560 

1901 

1,595 

47,850 

1,914 

1902 

1,764 

52.920 

2,117 

1903 

2,681 

92,025 

3,681 

1904 

.  . 

. . 

1905 

,   . 

. . 

1906 

•  • 

Elsewhere  in  Spain  gold  in  minute  quantities  has  been  reported 
from  the  Sierra  da  Gaudarrama,  near  San  Ildefonsa,  in  Segovia; 
from  Membris  in  Caceres  ;  from  Culera  in  Gerona,  on  the  south  side 


aSowerby,  Jour.  Soc.  Arts,  XXXIII.,   1884,  p.  359. 
6  Bourdnriat,  Bull.  Soc.  Beige  de  Geol.,  VII,  1894,  p.  50. 
c  Estadistica  Minera  de  Espana,  Madrid,  1901-1905. 


148  EUROPE. 

of  the  Pyrenees  ;  from  La  Nava  de  Jadraque  in  Guadaljara  ;  from 
Las  Hurdes,  Caceres,  and  Escambrax  ;  and  from  Penaflor  in 
Seville. a 


FRANCE. 

Numerous  streams  in  France  are  reported  to  be  gold-bearing. 
These  are  mainly  in  the  departments  of  Ariege,  Garonne,  Tarn,  and 
Herault,  where  the  streams  flow  northward  from  the  Pyrenees  ;  and 
in  the  departments  of  Ardennes  and  Meurthe-et-Moselle  in  the 
north,  very  near  the  German  frontier.6 

The  southern  deposits  have  been  worked  spasmodically  since 
Roman  times.  The  wealth  of  the  French  rivers  was  highly 
esteemed  by  Strabo,  Diodorus,  and  other  ancient  writers. 
Some  of  the  streams,  as  the  Ariege  (Aurigera),  indeed,  owe 
their  names  to  the  presence  of  gold.c  The  Ariege  is  auriferous- 
between  Foix  and  Pamiers,  and  nuggets  weighing  \  oz.  have 
been  found  in  its  sands. d  The  source  of  the  gold  appears  to  be  in  the 
Pyrenees.  At  La  Caunette,  however,  in  the  north  of  the  Depart- 
ment of  Aude,  are  numerous  small  pyritous  quartz  veins,  in  mica- 
schists  and  gneiss,  that  are  occasionally  auriferous  to  the  extent 
of  5  oz.  to  1  oz.  per  ton.  These  and  similar  veins  may  have 
furnished  some  portion  of  the  alluvial  gold  of  the  neighbouring 
streams.e 

In  the  Erieux  stream,  Dep.  de  l'Ardeche,  there  was  found  a 
nugget  of  gold  weighing  17 \  ounces  (537  grammes).  Fairly  large 
plates  of  gold  have  also  been  obtained  near  La  Voulte  on  the 
right  bank  of  the  Rhone.  The  Rhone  elsewhere,  as  on  the  left 
bank  at  La  Roche-de-Glun,  and  near  Givors,  &c,  carries  auriferous 
gravels  that  were  formerly  washed  for  gold. 

Ancient  alluvial  deposits  have  possibly  furnished  the  gold  of  a 
Carboniferous  conglomerate  near  Bessieges,  in  the  Department  of 
Gard,  in  the  Cevennes,  where  gold  occurs  in  minute  quantities 
in  the  quartzose  pebbles  of  the  Millstone  Grit.'  LaurS1  records  the 

a  Navarro,  Act.  Soc.  Espafi.  Hist.  Nat.,  II,  July,  1893  ;  III,  Feb.,  1894  ;  Paillette, 
Bull.  Soc.  Geol.,  2,  IX,  1852,  p.  482 ;  Antissier,  Bull.  Soc.  Ind.  Min.,  St.  Etienne,  XIII,. 
1884,  p.  125 ;  Nogues,  lb.,  XIV,  1885,  p.  931  ;  Id.,  Compt.  Rend.  Acad.  Sci.,  XCVIII,. 
1884,  p.  760. 

h  Dewalque,  Ann.  Soc.  Geol.  Belg.,  XXIII,  1895,  p.  43. 

c  Caraven-Cachin,  Bull.  Soc.  d'Hist.  Nat.  Toulouse,  XXXIV,  1901,  p.  66. 

d  Loc.  cit.,  p.  70. 

e  Bernard,  Annales  des  Mines,  Ser.  9,  XI,  1897,  p.  602. 

/Simonin,  Compt.  Rend.  Acad.  Sci.,  LXII,  1886,  p.  1042. 

g  Compt.  Rend.  Acad.  Sci.,  Paris,  CXLII,  1906,  p.  1410. 


FRANCE. 


149 


presence  of  gold  in  the  Trias  (Keuper),  from  which  an  assay  of 
a  sandy  dolomite  (near  Raucourt,  Dep.  de  Meurthe-et-Moselle) 
yielded  as  much  as  1|  ounces  per  ton  of  rock,  while  other  assays 
from  greater  depths  gave  4  dwts.  and  2i  dwts.  per  ton  ! 

The  only  gold-vein  of  importance  worked  in  France  in  former 
times  was  that  of  La  Gardette  in  the  department  of  Isere,  near 
Bourg  d'Oisans,  east-south-east  of  Grenoble.  It  has  been  known 
since  Greek  and  Roman  times,  and  has  since  then  been  worked  in 
desultory  fashion.  At  times  its  yield  has  given  rise  to  considerable 
excitement,  and  this  was  particularly  the  case  in  the  years  1733,  1781, 
and  1841.  The  gold  occurs  in  a  quartz- vein  traversing  a  gneiss 
which  is  overlain  unconformably  by  dolomitic  beds.     The  gneiss 


z: 


a- 


-><■ 


_N" 


/ 


-V 


£^r 


fe 


~y^\ 


\/Jr 


s  "s-JX. 


'/ 


•/, 


Fig.  74.     Cross -section,  showing  La  Gardette  Lode  (c,  b,  n)  (Rickard). 

is  part  of  a  series  of  schistose  rocks  that  has  apparently  suffered 
metamorphism  in  Permo-Carboniferous  times.  The  vein  ceases 
abruptly  at  the  old  eroded  surface  of  "the  gneiss.  Its  strike  is 
nearly  due  east  and  west,  and  it  is  exceedingly  well  denned.  The 
gangue  is  a  remarkably  banded,  ribboned,  and  laminated  quartz. 
The  walls  of  the  veins  are  well  slickensided.  Galena,  and 
copper  and  iron  pyrites  accompany  the  gold,  the  first  being  the 
most  favourable  for  the  occurrence  of  gold.  According  to  Rickard" 
the  infilling  of  the  fissure  was  later  than  Triassic  times,  and  is 
possibly  to  be  associated  with  the  intrusion  of  an  amygdaloidal 
diabase  which  occurs  in  the  neighbourhood.  The  yield  of  the  La 
Gardette  mine  has  on  the  whole  been  insignificant  since  its  upper 


«  Trans.  Am.  Inst.  M.E.,  XXI,  1892,  p.  84. 


1 50  EUROPE. 

enriched  portions  have  been  exhausted.     The  total  vertical  depth 
explored  exceeds  400  feet. 

Four  deposits  containing  gold  are  now  being  worked  in  France : 
(1)  La  Lucette,  near  Laval,  Department  de  Mayenne  ;  (2)  La  Belliere 
par  Montrevault,  St.  Pierre  Montlimart,  Department  de  Maine  et 
Loire  ;  (3)  Le  Chatelet,  Department  de  Creuse  ;  (4)  and  at  Carcas- 
sone,  Department  d'Aude. 

In  December,  1904,  the  first  gold-mill  (10-stamp)  in  France  was 
put  in  operation  at  La  Lucette  mine,  near  Laval,  in  the  Department 
of  Mayenne.  The  mine  is  mainly  worked  for  antimony,  and  produces 
some  150  tons  regulus  per  month.  The  gangue  is  quartz  with  auri- 
ferous mispickel.  The  daily  production  of  gold  in  1905  was  some 
32  ounces  (1  kilo),  in  the  form  of  concentrates  carrying  3  or  4  kilos 
gold  per  ton.  The  production  from  La  Lucette  mine  for  1905  was 
6,759  tons  ore,  worth  £10,158  (253,945  francs).  Seventy-five  tons  of 
very  rich  ore  were  treated  for  a  yield  of  more  than  2  ounces  per  ton. 
During  1907  these  mines  yielded  gold  to  the  value  of  £42,015 
(1,050,380  francs),  or  more  than  double  that  of  the  preceding  year.a 

At  La  Belliere,  in  the  Vendee,  an  ancient  Roman  quartz  mine 
carrying  auriferous  mispickel,  is  worked.6  The  Le  Chatelet  mines 
produced  during  the  month  of  December,  1907,  180  tons  (metric) 
ore  that  yielded  915-7  ounces  (28-483  kilos)  gold  worth  £3,873 
(96,843-55  francs).  In  addition  to  the  foregoing,  about  250  ounces 
(8  kg.)  were  obtained  by  cyaniding.  The  Le  Chatelet  installation 
contains  the  first  cyanide  mill  erected  in  France  for  the  treat- 
ment of  native  gold  ores.  The  Montrevault  and  Carcassone 
mines  yield  somewhat  less  than  Le  Chatelet.  At  Martigne- 
Ferchaud,  Department  of  Ille-et-Vilaine  (Brittany),  gold-bearing 
antimonite  veins  similar  to  those  of  La  Lucette  are  being  worked. 
Free  gold  is  rare.  The  antimonite  carries  about  9  grammes  per 
metric  ton,  while  associated-arsenopyrite  has  a  tenor  of  8  grammes. 
The  ore  occurs  in  irregular  quartz  veinlets  in  a  greenstone  (diorite 
or  diabase)  dyke  intrusive  through  clay-slates  of  Ordovician  age.c 

For  the  seven  years  from  1896  to  1902  inclusive,  the  average 
annual  gold  production  of  France  was  worth  a  little  less  than 
£30,000  stg.  In  1906,  41,400  metric  tons  ore  were  treated  for  a 
yield  of  24,267-6  ounces  (756  kg.)  gold,  worth  £35,529  only.^ 
The  total  gold  yield  of  France  in  the  beginning  of  1908  was  about 
3,700  ounces  per  month. 


a  Echo  des  Mines,  May  4,  1908. 

b  Strap,  Eng.  Min.  Jour.,  Feb.  9,  1905,  p.  280. 

cStutzer,  Zeit.  fur.  prakt.  Geol.,  XV,  1907,  p.  219. 

^Statist,  de  l'lnd.  Minerale  en  France,  &c,  pour  l'annee    190G. 


151 


SWITZERLAND. 

The  older  fundamental  rocks  of  the  Alpine  chain  contain 
sporadic  pyritous  occurrences  which  are  occasionally  auriferous. 
On  the  south  side  of  the  Simplon,  not  far  from  the  Swiss  boundary 
village  of  Gondo,  are  the  most  noteworthy  of  the  Swiss 
gold  occurrences.  Auriferous  veins  occur  here  in  the  region 
of  the  eastern  slopes  of  Monte  Rosa.  They  closely  resemble  those 
of  the  Val  d'Anzasca  on  the  Italian  side.  The  country  of  the  veins 
is  essentially  an  antigorite-gneiss.  The  vein  fissures  traversing  the 
gneiss  strike  N.  25°  W.,  and  dip  at  steep  angles  to  the  north-east. 

Some  ten  more  or  less  parallel  veins  occur  in  an  auriferous  zone 
about  1,100  yards  (a  kilometre)  in  width.  They  are  oxidised  to 
depths  of  from  60  to  150  feet,  and  have  there  been  worked  open- 
cast by  the  ancients.  Below  the  oxidised  zone  the  gangue  is  made 
up  of  country  and  quartz.  The  main  veins  are  crossed  by 
cupriferous  stringers.  The  richer  workable  portions  are  pockets 
from  13  to  66  feet  (4  to  20  m.)  long  and  rarely  more  than  1  foot 
(30  cm.)  wide.  The  gangue  is  quartz  and  calcite  ;  the  ore,  pyrite 
and  chalcopyrite  with  subordinate  galena  and  blende.  Free  gold  is 
no  longer  met  with.  The  average  value  of  the  better  ore  in  the 
Camozetta  vein  is  about  1  ounce  (30  grammes)  per  ton,  but  it  may 
reach  some  2|  ounces  per  ton.  The  period  of  maximum  production 
of  these  veins  appears  to  have  been  between  1820  and  1830.  Some 
were  worked  as  early  as  1810.  In  later  years  they  were  worked 
vigorously  in  1871,  and  again  from  1894  to  1896.a 

In  the  Canton  of  Ticino,  between  Lake  Maggiore  and  Lake 
Lugano,  auriferous  occurrences  have  been  met  with  at  Astano, 
Novaggio,  and  Tesserete.  South-east  of  Astano  in  the  Val  Tresa  are 
traces  of  old  gold  mines.  These  old  workings  have  fallen  in,  but  so 
far  as  may  be  seen,  the  veins  on  which  work  had  been  done  are  some 
6  feet  in  width.  The  gangue  is  quartz  and  carries  arsenopyrite, 
pyrite,  blende,  galena,  and  stibnite.  The  ores  are  ground  in  Pied- 
montese  mills  and  yield  from  1  to  2  ounces  gold  and  4  to  5  ounces 
silver  per  ton.  Similar  veins  were  found  in  1878  between  Novaggio 
and  Miglieglia,  some  2h  miles  east  of  Astano.  In  the  Monte  Cenere 
gneiss  in  the  north  of  Lugano,  2|  miles  from  Tesserete  in  Val 
Capriasca,  and  on  the  eastern  slope  of  Monte  Beglio,  is  an  auriferous 
lenticular  pyritous  lode,  the  lenses  of  which  attain  a  maximum 
thickness  of  some  8  inches  only.  The  pyrite  and  arsenopyrite  of  the 
vein,  as  well  as  the  quartz,  contain  gold. 

Auriferous  lollingite  veins  have  been  worked  near  Vernayaz 
at  the  foot  of  the  Dent  du  Midi,  Valais  Canton.     The  deposit  is  in 

a  Schmidt,  C,  Zeit,  fur  prakt,  Geo!.,  1903,  p.  205. 


152  EUROPE. 

gneiss,  but  only  a  few  yards  from  the  contact  with  Permian  sand- 
stones. It  has  a  thickness  in  its  richest  portion  of  some  6  feet 
and  a  length  of  150  to  300  feet.  The  gangue  is  mainly  calcite,  and 
the  ore  1611ingite.a 

The  Calanda  auriferous  veins,  lying  west  of  the  Rhine  Valley 
between  Chur  and  Mayenfeld  in  the  Grisons  Canton,  are  perhaps  the 
best  known  of  the  Swiss  occurrences.  The  veins  occur  on  the  south- 
west end  of  the  Calanda  mountains,  west  of  Felsberg.  The  lower 
part  of  the  Dogger  (Inferior  Oolite)  Beds  is  there  developed  as  a 
quartzose,  sericitic,  and  calcareous  clay  slate,  about  50  feet  thick. 
This  bed  is  traversed  by  veins,  stringers,  and  lenses  of  quartz  and 
calcite,  having  no  predominant  direction  of  strike.  The  sandy  slates 
of  the  series  are  impregnated  with  pyrite  and  arsenopyrite.  Native 
gold  is  found  in  the  veins  as  dust,  or  in  fine  dendritic  aggregates  and 
small  octahedral  crystals.  These  mines  were  especially  productive 
from  1809  to  1813,  and  were  again  worked  vigorously  from  1856  to 
1861.  The  tenor  of  the  ore  is  about  \  ounce  per  ton  (metric).  The 
largest  piece  of  free  gold  found  weighed  4  ounces  (125  grammes).6 

Alluvial  gold,  apparently  derived  from  the  above  or  from 
similar  occurrences,  is  found  along  the  Rhine  between  Chur  and 
Mayenfeld.  The  Aare  was  worked  for  gold  between  Olten  and 
Klingnau,  from  1834  to  1839,  when  the  washers  are  said  to  have 
earned  from  2  to  3  francs  (Is.  8d.  to  2s.  6d.)  per  day. 

Gold  has  been  found  in  the  Reuss  and  other  tributaries  of  the 
Rhine,  and  in  the  Emmen,  a  tributary  of  the  Aare,  but  nowhere  do 
these  deposits  appear  to  be  of  present  economic  importance. 


ITALY. 

The  ancient  gold  mines  and  deposits  of  northern  Piedmont  are 
mentioned  by  Pliny c  as  lying  near  the  village  of  the  Ictimuli  in  the 
Vercellian  territory.  He  refers  to  a  decree  forbidding  the  em- 
ployment of  more  than  5,000  slaves  in  these  mines.  The  mines  are 
mentioned  also  by  Strabo,d  who  describes  the  friction  that  had 
arisen  even  in  those  days  between  the  miners  and  the  cultivators, 
the  latter  complaining  of  loss  of  water  and  of  damage  to  the  soil 
from  the  debris  swept  down  the  streams  from  the  mines. 

In  modern  days  all,  or  nearly  all,  the  southward  flowing 
tributaries  of  the  Po  carry  alluvial  gold  in  small  grains  and 
spangles.    The  principal  streams  are  the  Malone,  Elvo,  Oreo,  Cervo, 

a  Schmidt  C,  Handworterbuck   der  Schweiz.    Volkwirtsch.  Sozialpol.  und  Verwalt., 
Basel,  1907,  p.  150. 

"  Schmidt,  C,  loc.  cit.,  p.  50. 

c  Hist.  Nat.,  Lib.  XXXIII,  21. 

"  Book  IV,  cap.  vi.,  par.  7. 


ITALY. 


153 


Dorea-balta,  Sesia,  and  Ticino,  in  Turin,  and  the  Adda,  Serio,  and 
Oglio,  in  Milan.  These  are  but  little  worked  at  the  present  time, 
although  in  1894  a  dredge  was  placed  on  the  Ticino  by  a  French 
company.  It  excavated  during  that  year  1,100  cubic  metres  of 
gravel  for  15-6  ounces  (485  grammes),  or  5£  grains  per  cubic  yard. 
Alluvial  gold  also  occurs  in  the  Orbo,  and  in  the  Val  Corsente  on  the 
northern  slopes  of  the  Ligurian  Apennines  on  the  north  of  Genoa. 


Fig.  7o.     Auriferous  Occurrences  of  Piedmont,  Northern'  Italy. 

The  auriferous  veins  of  Italy  lie  mainly  in  the  Western  Alps,  west 
and  north-west  of  Lake  Maggiore.  The  principal  valleys  are  the 
Upper  Sesia,  Toppa,  Anzasca,  Antrona,  and  Antigorio.  The  fineness 
of  the  alluvial  gold  is  about  920. a  In  these  valleys  the  veins  ordin- 
arily occur  as  thin  pyritous  seams  in  Permo-Carboniferous  quartzites, 
mica-schists,  and  gneiss.6  The  gold  occurs  generally  with  the 
pyrite,  and  is  rarely  free.  The  associates  of  the  auriferous  pyrites 
are   normally  chalcopyrite,   mispickel,  grey  copper-ore,  galena,  and 

a  Jervis,  "  Dell  'Oro  in  Natura,"    Turin,  1881,  pp.  68-71. 

"  De  Launay,  Comptes  Rend.  Congres  Geol.  Internat.,  1906,  p.  i>86. 


154 


EUROPE. 


blende.  The  auriferous  pyrite  lodes  in  the  Val  Antrona,  in  the 
vicinity  of  Monte  Rosa,  show  on  analysis  tenors  of  1 6  to  20  dwts. 
(21  to  31  grammes)  gold  per  ton,  but  of  this  only  from  |  to  1  dwt. 
is   recoverable  by  amalgamation." 

The  two  main  districts  are,  however,  those  of  Val  Toppa  and 
Pestarena.  In  the  first  locality  Upper  Palaeozoic  talcose  schists  form 
the  country,  and  through  them  straggle  irregular  pyritous  bodies 
with  many  secondary  ramifications.  At  Pestarena  on  the  other 
hand,  there  are  true  veins  disposed  fanwise.  Two  have  been  dis- 
tinguished, dipping  with  the  stratification  of  the  mica-schists.  Both 
are  cut  by  a  transverse  vein  and  are  enriched  at  the  junctions. 

An  English  company  has  for  many  years  carried  on  mining 
operations  in  the  Anzasca  valley,  working  mainly  on  the  Peschiera 
lode  at  Pestarena.  At  Val  Toppa  the  tenor  of  the  ore  is  9  dwts.  per 
ton  ;  at  Pestarena  11  dwts.  per  ton.  Everywhere  the  gold  occurs 
entirely  in  the  pyrites,  the  quartz  being  barren.  At  Battiggio  (Cani) 
veins  occur  in  mica-schists,  but  after  having  been  worked  extensively, 
in  the  eighteenth  century,  these  have  now  been  abandoned  owing  to 
the  large  percentage  of  arsenic  contained  in  them,  and  also  owing  to 
their  low  gold  tenor. 

The  veins  of  the  Val  d' Anzasca  appear  on  the  whole  to  have 
been  the  most  productive  of  Italian  gold  mines  in  the  past.  The 
principal  were  those  of  Peschiera  (Pestarena),  and  Cavone.  The 
last  reached  its  maximum  production  as  long  ago  as  1790,  when, 
in  two  years,  some  £23,000  gold  was  produced. b  The  name  Pestarena 
is  itself  indicative  of  the  great  number  of  small  Piedmontese  crushing 
(pestare)  mills  in  the  neighbourhood.  The  annual  production  of  these 
mines  for  the  period  immediately  prior  to  1827  was  about  119 
metric  pounds  gold,  worth,  say,  £17,810  (Lire  445,300),  of  which, 
however,  only  some  12  to  15  per  cent,  was  profit. 

The  Pestarena  United  Mines  included  Peschiera,  Kint,  Stabioli, 
Cani  (Battiggio),  and  also  Carboniera  d' Alberto  (Val  Toppa).  The 
value  of  the  Peschiera  bullion  was  £3.  8s.  l|d.,  and  its  fineness 
754.  Work  on  these  mines  was  suspended  in  1900.  They  had  during 
the  later  years  of  operation  produced  as  follows  : — c 


Long  tons 

Crude  Ounces 

Value. 

Annual    Profit 

crushed. 

Gold. 

Sterling. 

or  Loss. 

Oct.,  1896,  to 

£ 

£ 

Dec, 1897 

6,929 

10,884 

37,053 

+  10,551 

1898 

5,270 

6,386 

21,192 

—  3,363 

1899 

5,210 

3,477 

10,357 

—  5,904 

1900 

2.734 

1,362 

3.791 

—  5.783 

aLenicque,  Bull,  de  la  Soc.  de  1'  Indust.  Min.,  May,  1907. 

&  Fantonetti,  "  Le  Miniere  Metalliche  dell'Ossole  in  Piemonte,"  Milan,  1830. 

c  Ann.  Reports  Pestarena  United  Mines  Company. 


I 'tnh    IV 


Val  de  Ohallant.  Piedmont,  Italy. 


Val  d'Anzasca,   near  Macugnaga,  Piedmont.  Italy. 


ITALY. 


155 


In  the  Val  Antigorio  the  chief  gold  mine  worked  was  Crodo. 
It  was  very  productive  during  the  last  years  of  the  eighteenth 
century,  and  is  locally  believed  to  have  furnished  the  funds  for  the 
construction  of  the  magnificent  Marini  Palace  at  Milan.  In  the  Val 
Antrona,  at  Trivera  and  Alle  Mi,  refractory  auriferous  sulphide 
(arsenopyrite  and  pyrrhotite)  veins  occur.  None  of  these  mines  were 
worked  much  earlier  than  the  commencement  of  the  nineteenth 
century.  Numerous  small  veins  exist  high  up  on  the  spurs  of 
Monte  Rosa,  and  in  the  Val  Moriana  facing  Pestarena,  but  are 
unworkable  owing  to  the  high  transport  costs. 

In  the  Val  de  Challant,  a  left-hand  tributary  valley  of  the 
Dorea  Balta,  is  the  Evancon  mine,  the  only  important  gold  mine 
working  in  Italy  in  1908.  It  lies  above  Brusson,  and  comprises 
several  widely  separated  veins,  of  which  the  Finnallaz  is  the  chief. 
The  veins  cut  transversely  through  gneiss  and  the  overlying  rocks, 
which  are  amphibolite  and  crystalline  limestone,  the  whole  series 
dipping  sharply  into  the  hiD.  It  is,  however,  only  for  the  few 
hundred  feet  that  the  veins  pass  through  the  amphibolite  members 
of  the  series  that  they  are  auriferous.  Unlike  the  great  majority  of 
the  Italian  occurrences  above-mentioned,  the  gold  is  free,  is  often 
crystallized,  and  occurs  disseminated  through  clear  quartz,  in  shoots 
and  pockets,  some  of  the  latter  being  exceedingly  rich  in  quality  if 
small  in  extent." 

At  Monte  Loreto,  east  of  Genoa,  auriferous  chalcopyrite  occurs 
in  a  gangue  of  calcite  and  quartz.  The  gold  liberated  from  the 
chalcopyrite  has  been  found  in  the  form  of  octahedral  crystals. 
Masses  of  crystallized  gold  weighing  several  pounds  are  reported  to 
have  been  obtained  from  these  veins. 

It  is  estimated  that  since  1860  no  less  than  £1,520,000  (38,000,000 
lire)  have  been  spent  on  the  Italian  Alpine  gold  veins  for  a  total 
return  in  gold  of  only  £680,000  (17,000,000  lire). 

The  gold  production  of  Italy  during  recent  years  is  shown  in 
the  following  table  : — b 


*  Estimated. 

"Schmidt,  C,   " Geologisches   Gutachten    iiber  die   goldfuhrenden   Gange  tei 
Brusson  in  Piemont,"  Bern,   1900. 

"  Revista  del  Servizio  Minerario  nel  1900-1906. 


156  EUROPE. 


SERVIA. 


The  metalliferous  region  of  Eastern  Servia  lies  south  of  the 
Danube  and  between  the  Morava  and  the  Timok,  both  northward- 
flowing  tributaries  of  the  great  river.  The  region  is  therefore  the 
southerly  continuation  across  the  Danube  of  the  Transylvanian 
Alps  that  connect  the  Carpathians  and  the  Balkans  ;  it  is  in  forcing  a 
passage  through  these  connecting  ranges  that  the  Danube  has  formed 
the  famous  gorge  of  the  "Iron  Gates."  The  highest  mountains  in 
Eastern  Servia  are  the  Stara  Planina  on  the  Bulgarian  frontier,  with 
a  maximum  height  (in  Midzor  peak)  of  7,106  feet.  In  the  mineral 
region  itself  the  mountains  attain  an  altitude  of  some  4,000  feet, 
promising,  therefore,  from  their  streams  and  waterfalls  an  abundant 
supply  of  electrical  power. 

Mining  has  been  carried  on  in  Servia  from  the  most  ancient  times, 
and  numerous  legends  have  consequently  gathered  around  the  in- 
dustry. In  this  connection  it  is  interesting  to  note  the  resemblance  of 
one  of  these,  accounting  for  the  abandonment  of  the  "  Lakudin  Beg  " 
gold  mine  in  the  Pek  Valley,  to  that  advanced  by  the  Tibetan 
miners  for  a  similar  sudden  abandonment  of  goldfields."  In  the 
Servian  variant  the  diggers  found  a  magnificent  golden  plough, 
and  :' craignant  une  malediction  d'en  haut  "6  incontinently 
ceased  work.  There  appear  to  have  been  two  distinct  periods  in 
ancient  Servian  mining,  Latin  and  Slav;  of  the  former  but  few 
traces  now  remain.  The  latter  is  best  denned  by  the  coins  and 
jewels  occasionally  met  with  in  the  placers.  The  ancient  workings 
were  shallow,  owing  probably  to  the  lack  of  pumping  facilities. 
With  the  advent  of  Saxon  miners,  circa  1244  a.d.,  the  Servian 
mineral  industry  assumed  considerable  importance,  and  from  thence 
onwards  numerous  references  are  made  in  the  literature  of  the 
Middle  Ages  to  the  gold  mines  of  Servia.  During  the  northward 
extension  of  the  Turkish  arms  in  the  fifteenth  century,  the  miners 
were  swept  across  the  Danube  before  the  Moslem  hordes,  and  the 
history  of  the  Servian  mines  was  closed  for  four  centuries.  Mining 
operations  were  finally  resumed  in  1849.  Old  workings  are  especially 
numerous  in  the  valleys  of  the  Pek,  Mlava,  and  Timok. 

The  Stara  Planina,  the  mountain  range  on  the  Servo-Bulgarian 
frontier,  is  composed  mainly  of  metamorphic  and  crystalline  schists, 
which  stretch  northward  from  Midzor  peak  to  Golubac,  Dobra,  and 
Orsava  on  the  Danube,  with,  however,  a  slight  break  in  their  con- 
tinuity near  Zajecar.     The  metamorphic  rocks  and  schists  comprise 

a  Maclaren,  Min.  Jour.,  June  22,  1907. 

°  Jovanoviteh,  "  Or  et  Cuivre  de  la  Serbie  Orientale,"  Paris,  1907. 


SERVIA.  157 

gneiss,  amphibolite-schists,  mica-schists,  talc-schists,  phyllites,  and 
quartzites.  Pala?ozoic  rocks  occur  as  two  large  areas  to  the  west 
of  the  foregoing  crystalline  rocks,  and  are,  in  the  main,  slates,  schists, 
and  quartzites.  Overlying  these  are  Mesozoic  beds — Permo-Trias, 
Jurassic,  and  Neocomian.  A  great  part  of  the  region  is  covered 
by  fossiliferous  Cretaceous  limestone.  Tertiary  deposits  also  bulk 
large  between  the  Morava  and  the  Timok.  They  represent 
Miocene  deposits  of  the  Mediterranean,  Sarmatian,  and  Levantine 
stages. 

Among  the  eruptive  rocks  are  Archaean  and  Palaeozoic  granites, 
granulites,  porphyries,  and  porphyrites.  Towards  the  close  of 
the  Mesozoic  there  appeared  euphotides,  peridotites,  diorites, 
diabases,  and  lamprophyres.  These  basic  intrusions  ceased  before 
the  Tertiary  period,  which  is  characterised  (as  in  the  auriferous 
regions  of  Transylvania)  by  the  appearance  of  andesites,  dacites,  and 
trachytes,  closely  connected,  especially  the  first,  with  the  mineral  filling 
of  the  veins,  which  is  probably  of  Miocene  age.  Andesitic  rock  is  the 
country  of  the  veins  of  Bor,  Krivelj,  Metovonica,  Zlot,  and  Savinac. 
The  gold-quartz  veins  of  Deli-Jovan,  although  the  country  is  serpen- 
tinous,  owe  their  gold  to  andesite,  and  where  this  rock  is  absent 
there  also  is  mineralisation  absent.  At  Majdanpek  and  Kucajna 
andesite  occupies  an  equally  important  place.  The  auriferous 
minerals  of  the  former  mines  are  quartz,  galena,  pyrite,  blende,  and 
chalcopyrite,  while  at  the  latter  place,  where  andesite  is  intrusive 
through  limestone,  masses  of  auriferous  galena  have  been  deposited 
along  the  contacts.  Similar  relations  exist  at  Ridang,  on  the  Danube 
north  of  Kucajna,  and  also  to  the  south-west  in  the  districts  of 
Bistrica  and  Breznica.  In  short,  in  all  the  places  distinguished  by 
the  presence  of  chalcopyrite,  galena,  blende,  or  pyrite,  with  or  without 
gold,  andesites  are  the  enclosing  rocks,  or  are  found  in  the  immediate 
neighbourhood.  It  is  from  the  degradation  of  these  and  similar 
pyritous  veins  that  the  alluvial  deposits  have  derived  their  gold 
content. 

Native  amalgam,  often  accompanied  by  cinnabar,  is  found  by 
the  native  washers.  It  occurs  in  light-grey,  rounded  grains,  and  is 
known  as  "  zivak."  Its  composition  appears  to  be  :  Hg,  30-96  per 
cent.  ;   Au,  55-81  per  cent.  ;   Ag,  13-23  per  cent. 

According  to  Jovanovitch,  the  alluvial  gold  (a)  from  andesitic 
quartz  veins  contains  very  little  silver  ;  (b)  from  serpentine  (eupho- 
tide)  contains  8  to  10  per  cent,  silver  ;  (c)  from  the  crystalline  schists 
contains  as  much  as  30  per  cent,  silver — results  which  certainly  do 
not  accord  with  experience  in  other  parts  of  the  world.  The  alluvial 
gold,  as  a  rule,  is  very  fine  in  grain  ;  but  from  Gindusa  slugs  as  large 
as  a  hazel  nut  have  been  obtained  ;   while  at  Crista-Pucina  in  1886, 


158  EUROPE. 

a  labourer  working  in  his  field  found  a  nugget  7  ounces  (218  grammes) 
in  weight.  Numerous  pepites  occur  in  the  washings  of  Deli-Jovan 
and  of  the  Pek  river.  In  the  veins,  and  especially  in  those  in  the 
mica-schist,  gold  is  always  absent  when  pyrite  and  chalcopyrite 
are  lacking.  These  minerals  occur  either  in  pockets  or  disseminated 
throughout  the  quartz  and  country.  In  pyritous  veins  it  seems  fairly 
well  established  that  the  gold  content  diminishes  with  increasing 
depth.  The  Wilfley  table  concentrates  (sulphides)  of  the  St.  Anne 
(Deli-Jovan)  mine  average  from  2  to  3  ounces  gold  per  ton.  Chalco- 
pyrite itself  carries  from  2  to  15  dwts.  gold  per  ton.  Arsenical 
pyrites  and  galena  also  carry  gold.  Galena  is  encountered  more 
frequently  in  the  metamorphic  rocks  than  in  the  andesite.  Its 
tenor  ranges  from  lh  to  20  dwts.  in  gold. 

Kueajna  Mines. — These  lie  on  a  mineral  concession  of  160 
hectares  (395-3  acres)  to  which  are  added  subsidiary  concessions. 
Explorations  were  commenced  here  in  1862.  The  mines  at  first 
promised  to  be  successful,  but  collapse  came  when  an  unfortunate 
fire  destroyed  the  surface  works.  The  gold-quartz  veins  carry 
galena,  blende,  and  pyrite.  They  have  been  followed  to  a  depth  of 
320  feet  below  the  surface.  From  1873  to  1892  work  has  been  carried 
on  spasmodically.  During  eight  years  only  of  this  period  was  smelt- 
ing effected,  and  then  not  continuously.  Nevertheless,  the  veins 
have  produced  267' 133  metric  tons  lead,  139-4  metric  tons  zinc, 
41,566  ounces  silver,  and  2,005  ounces  gold.  The  thickness  of  the 
veins  is  extremely  variable,  ranging  from  6  inches  to  5  feet. 

St.  Barbc  Mines  (Blagojev-Kamen). — These  are  on  the  upper 
valleys  of  the  Pek,  between  Neresnica  and  Majdanpek.  The  region 
is  well  wooded,  and  contains  old  workings  which  at  the  St.  Barbe 
mines  cover  1,250  acres.  The  gold-quartz  veins  contain  pyrite, 
chalcopyrite,  and  galena,  giving  occasionally  very  high  assays. 
Work  on  this  concession  has  as  yet  been  purely  exploratory ;  never- 
theless, according  to  Jovanovitch,a  they  have  shown  that  there  are 
nearly  600,000  tons  of  ore  available  for  exploitation. 

St.  Anne  Mines  (Deli-Jovan). — Numerous  old  workings  occur 
here,  and  it  was  from  here  also  that  the  nugget  of  7  ounces  weight 
already  mentioned  was  obtained.  The  country  is  serpentine 
(euphotide),  and  comprises  the  massif  of  Deli-Jovan.  The 
minerals  in  the  veins  are  the  same  as  those  of  the  foregoing  mines. 
The  pyrites  when  concentrated  may  carry  as  much  as  1J  to  6f 
ounces  of  gold.  From  the  shafts  and  levels  on  this  property  many 
thousands  of  tons  of  ore  have  been  extracted.  In  1900  a  trial  parcel 
of  97-876    metric    tons    of    concentrates   was    sent    to    Kremnitz 

a  Loc.  cit.  sup. 


SERVIA. 


159 


(Hungary)  ;  from  it   were   extracted   332  ounces  of  gold  and  626 
ounces  silver. 

Alluvial  Deposits. — The  Pek  river  carries  alluvial  gold  from 
its  source  to  its  mouth,  but  from  the  time  it  leaves  the  Kucevska 
defile  until  it  reaches  the  Danube  the  gold  is  too  widely  scattered 
over  the  broad  valley  to  be  of  economic  importance.  Even  on  the 
shores  of  the  Danube  the  sands  are  faintly  auriferous.  The  chief 
dredging  area  on  the  Pek  river  lies  in  the  broad  valley-plain  between 
Kucevo  and  Neresnica.  At  the  latter  place,  "  La  Societe  d'Exploita- 
tions  Minieres,"  of  Brussels  (formerly  the  Servian  Dredging  and 
Mining  Syndicate,  of  London),  had  in  1906  three  dredgers  working. 
Prospecting  with  Keystone  drills  in  this  area  gave  over  a  total 
length  of  650  yards  an  average  tenor  of  13i  grains  per  cubic  yard. 
Working  results  have,  however,  been  as  follows  : — 


Dredge  No.  1. 

Year. 

Total 

Hours 

Worked. 

Hours  of 

Actual 
Dredging. 

Quantity 
Cubic 
Yards. 

Yield. 
Ounces. 

Cost 

per 

Cubic 

Yard. 

Hours  of 

Actual 

Dredging 

per  Month 

Cubic 

Yards 

per  Hour 

Value  of 
Gravel 

per  Cubic 
Yard. 

1903-4... 
1904-5... 

3,768 
5,349 

2,891 
4,637 

135,356 
203,507 

1,076 
1,226 

d. 

2-5 
2-8 

361-3 
488-1 

46-9 
43-8 

d. 

7-6 
5-8 

Dredge  No.  2. 

Year. 

Total 

Hours 

Worked. 

Hours  of 

Actual 

Dredging. 

Quantity 
Cubic 
Yards. 

Yield. 
Ounces. 

Cost 

per 

Cubic 

Yard. 

Hours  of 

Actual 

Dredging 

per  Month 

Cubic 

Yards 

per  Hour 

Value  of 

Gravel 

per  Cubic 

Yard. 

1903-4... 
1904-5... 

1,569 

5,582i 

1,312 
4,645 

55,264 
185,473 

361 
1,469 

d. 
2  4 
32 

3706 
464-5 

496 
39-8 

d. 
5-4 
7-6 

From  March  21st  to  December  31st,  1906,  the  results  were  still 
lower,  but  the  three  dredgers  were  then  engaged  in  cutting  a 
channel  through  barren  ground  to  reach  better  gravels.  Neverthe- 
less, the  three  dredges  returned  : — 


Hours 
Actually 
Dredged. 

Cubic 

Yards 

Raised. 

Cubic 

Yards  per 

Hour. 

Yield. 
Ounces. 

Value. 

Value  of  Gravel 

per 

Cubic  Yard. 

9,794 

621,060 

63  3 

3,082 

£12,069 

d. 

4-7 

The  Bela-Reka  auriferous  alluvials  have  a  total  thickness  of 
some  10  to  13  feet,  but  of  this  only  about  2|  feet  are  really  productive. 
The  overlying  barren  sands  are  from  3£  to  4  feet  thick.  The  value 
appears  to  be  about  8  grains  per  cubic  yard  (1-34  francs  per  cubic 
metre). 


160 


EUROPE. 


In  the  lower  Timok  valley  the  gravels  have  much  the  same 
thickness  and  disposition  as  in  the  Bela-Reka,  but  their  value  is 
slightly  less — viz.,  about  6|  grains  per  cubic  yard.  The  upper 
Timok  has  been  examined  by  M.  D.  Levat,  who  found  the  valley 
very  broad  in  places,  reaching  a  maximum  width  of  660  yards.  Of 
53  bores  put  down  none  proved  barren,  and  the  average  value  was 
stated  to  be  12 \  grains  per  cubic  yard  (1  92  francs  per  cubic  metre). 
This  result  was  considered  to  be  sufficiently  encouraging  to  proceed 
with  the  erection  of  dredges  on  the  Timok  river. 

The  gold  production  of  Servia  during  the  present  century  has 
been  : — 


Kg.  Fine  Gold. 

Value  in  Francs. 

Value,  Sterling. 

1901 

30 

98,881 

£ 

3,955 

1902 

19 

92,939 

3,717 

1903 

11 

34,802 

1,392 

1904 

85 

258,236 

10,329 

1905 

87 

251,494 

10,059 

1906 

128 

374,267 

14,990 

TURKEY. 

Ancient  writers  make  occasional  references  to  the  gold  of  the 
region  now  known  as  Turkey-in-Europe.  Strabo  mentions  gold 
placers  on  the  east  of  the  Strymonic  Gulf  (mod.  Orphani),  near 
Mount  Pangaeus.  These  were  worked  by  Philip  of  Macedon  in 
358  B.C.  Herodotus  also  describes  these  gold  occurrences  as  lying 
on  the  Thracian  coast  opposite  Thasos,  while  he  refers  to  the 
island  of  Thasos  as  being  itself  auriferous.  The  auriferous 
country  of  the  mainland  lay  between  the  Strymon  (Struma)  and 
Nestus  (Mesta  Kara  Su)  rivers,  both  flowing  into  the  iEgean  Sea, 
north  and  west  respectively  of  the  island  of  Thasos.  Nothing, 
however,  is  known  at  the  present  day  of  the  economic  possibilities 
of  these  placers  of  the  ancients. 

The  Turkish  Empire  during  the  years  1902-1904  is  believed  to 
have  produced  in  gold  the  following  : — 


Fine  Ounces. 

Value,  Sterling. 

1902 
1903 
1904 

1,480 

999 

1,400 

£ 
6,286 
4,242 
5,945 

TURKEY.  161 

All  this  must  be  regarded  as  having  been  derived  from  the 
Bulgar  Ma'aden  mines  in  Asia  Minor,  and  not  from  Turkey- 
in-Europe. 

GREECE. 

Native  gold  is  not  recovered  in  Greece  at  the  present  day.  It 
has  been  found,  nevertheless,  in  alluvial  deposits  near  the  town  of 
Skyros  in  the  island  of  the  same  name  ;  in  the  vicinity  of  the  village 
of  Doliana  (Arcadia)  in  small  quantity  in  pyritiferous  veins ; 
and  also  with  silver  in  the  argentiferous  galena  of  the  famous  mines 
of  Laurium.  The  ancient  Greeks  worked  gold  mines  in  the  islands 
of  Cyprus  and  of  Siphanto  (Siphnos)  in  the  Cyclades  group. 
Reference  is  made  to  these  placer  deposits  both  by  Pausanias" 
and  Herodotus. h 

ROUMANIA. 

Gold  occurs  in  very  small  quantities  in  the  river  sands  of  the 
Juil,  Oltul,  Argesul,  Bistritza,  and  their  mountain  affluents.0  The 
Bistritza  rises  in  the  Rodna  mountains  in  Eastern  Hungary,  flows 
through  the  south  corner  of  Bukowina,  and  thence  through  Moldavia 
to  join  the  Danube.  Its  gold  has  doubtless  been  derived  from 
auriferous  veins  in  andesite,  similar  to  those  of  Nagybanya. 
Gold-quartz  veins  are,  moreover,  known  in  the  portion  of  the 
Carpathians  through  which  the  Upper  Bistritza  flows. 


AUSTRIA-HUNGARY. 

Bohemia. — The  gold  mines  of  Eule-Jilova,  10  miles  south  of 
Prague,  between  the  valleys  of  the  Sazava  and  the  Libre,  were 
being  worked  in  734  a.d.  They  are  said  to  have  yielded  in  one 
year  1|  million  ducats  gold,  and  again  in  1145  a.d.  to  have  pro- 
duced more  than  a  ton  of  pure  metal.  The  Borkowitz  mines  in  the 
Kuttenberg  district  are  also  worked  for  gold. 

The  pyritous  gold- veins  of  Mount  Roudny,  the  only  gold  mine 
of  present  importance  in  Bohemia,  lie  9i  miles  east  of  Wotitz  and  37 
miles  south-south-west  of  Prague.  They  have  recently  been 
re-opened  by  a  British  company  after  an  abandonment  of  nearly 
a  century,  having  previously  been  worked  intermittently  from 
the  fourteenth  century  to  1804.  The  country  of  the  veins 
is    a   grey    biotite-granite,     which    becomes    gneissose    in    places, 

a  Lib.,  X.,  cap.  XI. 

b  I,  225,  Thalia  III,  57. 

c  Poni,  Ann.  Sci.  de  l'Univ.  de  Jassy,  I,  1900,  p.  145. 


162  EUROPE. 

and  which  is  associated  with  amphibolite.  Both  granite  and 
amphibolite  are  traversed  by  aplitic  dykes.  The  rocks  are 
crossed  by  a  system  of  east  and  west  pyritous  fissures,  only 
a  few  inches  in  thickness.  The  adjacent  country  is  also  im- 
pregnated with  pyrite.  The  gold  usually  occurs  associated  with  the 
pyrite,  but  is  also  found  native,  either  finely  divided  in  the  quartz, 
or  as  flakes  and  crystals  in  the  veinlets.  The  thinnest  veins  are  the 
richest,  and  finely  crystallized  pyrites  contains  more  gold  than  the 
coarsely  crystallized.  The  amphibolites  contain  little  or  no  gold. 
Auriferous  deposition  and  alteration  of  the  granite  walls  preceded 
the  formation  of  the  aplitic  dykes/1  In  1906  the  Mount  Roudny 
mines  crushed  32,985  tons  ore  for  a  yield  of  3,977-5  ounces 
(123- 9  kg.),  worth  £16,882.^  Other  minor  gold  occurrences  of 
similar  character  in  Bohemia  are  fully  described  by  Posepny.c 

In  Southern  Bohemia  gold-quartz  veins  occur  in  gneiss,  mica- 
schist,  chlorite-schist,  and  greenstone.  The  quartz  of  the  Kasejo- 
witz  (Kasejovic)  veins  is  white  and  clean,  with  visible  grains  of  a 
gold-telluride  mineral  resembling  nagyagite,  from  which  the  free 
gold  of  the  vein  has  originated.  Assays  have  shown  tenors  of 
from  f  to  2|  ounces  gold  per  metric  ton.  The  veins  appear 
to  be  at  the  contact  of  the  gneiss  with  granite  apophyses. 
With  the  quartz  is  associated  auriferous  arsenical  pyrites 
and  gold-tellurides  (nagyagite,  petzite,  and  sylvanite).'^ 
North-north-west  of  the  town  of  Wolin  are  the  Na  Zlatnici 
veins,  worked  in  the  eighteenth  and  nineteenth  centuries.  These 
also  are  at  granite  and  gneiss  contacts.  Similar  veins  are  known  at 
other  places  in  the  neighbourhood.  The  Otava  river  gravels  carry 
an  average  tenor  of  2  grains  per  cubic  yard  (17  mg.  per  cubic 
metre),  a  tenor,  of  course,  too  small  for  profit.0 

Austrian  Silesia. — The  earliest  record  of  gold-mining  in 
Austrian  Silesia  is  dated  1556  a.d.,  and  the  positions  of  many  of  the 
mines  then  worked  are  still  known.  These  lie  in  the  Hohenberg  and 
Oelberg  mountains  at  and  in  the  vicinity  of  Wurbenthal,  Engelsberg, 
and  Freiwaldau,  all  in  the  north-west  of  the  province.  The  lodes 
are  in  clay-slates  that  are  associated  with  chlorite-schist,  quartzose 
schist,  and  diorite,  the  whole  series  resting  on  Archaean  gneiss. 
The  veinstone  is  quartz,  and  carries  pyrite  and  galena.  The  value 
of  the  richer  ore  varies  from  17  to  36  dwts.  per  ton.     All  the  streams 

a  Krusch,  Zeit.  der  deutsch  geol.  Gesellsch.,  1902,  LIV,  p.  58. 

h  Forbes,  Cons.  Rep.,  1908. 

c  Archiv.  fur  prakt.  Geol.,  II,  1895,  p.  79. 

d  Holy,  Oesterr.  Zeit.  fur  Berg-  und  Hutt.,  April  4,  1908,  p.  1. 

e  Zelizko,  Zeit.  fur  prakt.  Geol.,  XVI,  1908,  p.  (53. 


AUSTRIA.  163 

flowing  from  the  Hohenberg  and  Oelberg  mountains,   and    more 
especially  the  Oppa  and  Biela,  contain  small  quantities  of  gold." 

Tyrol. — Gold-mining  in  the  eastern  Tyrol  is  believed  to  date 
from  1427  a.d.  The  well-known  Heinzenberg  mines  near  Zell  in 
the  Ziller  Thai  were  opened  up  some  12  years  later,  but  were  not 
extensively  worked  until  1628.  In  1630  rich  alluvial  deposits  and 
quartz-veins  were  found.  The  apportionment  of  the  prospective 
profits  from  these  deposits  nearly  led  to  war  between  the 
owners,  the  Archduke  Leopold  of  Austria  and  the  Archbishop 
of  Salzburg.  The  gold  tenor  of  the  veins  was  then  from 
1£  to  2  ounces  per  ton.  The  upper  oxidised  zones  were  rich 
and  were  easily  mined  and  milled,  but  in  depth  the  free 
gold  was  replaced  by  refractory  auriferous  arsenical  pyrites, 
from  which  the  gold  was  obtained  with  great  difficulty.  In 
1681  some  400  workmen  were  employed,  and  quantities  of  quartz 
of  a  tenor  of  107  ounces  per  ton  were  being  obtained.  In  the 
eighteenth  century  the  yield  steadily  declined,  and  from  1794  to  the 
year  1869,  when  the  Heinzenberg  (Vincenzi)  mines  were  finally 
closed  down  owing  to  an  inrush  of  water,  the  annual  yield  had  been 
only  some  150  to  160  ounces.  The  veins  lie  in  mica-schists,  phyllites, 
and  talc-schists.  They  are  numerous  but  low-grade,  and  vary  in 
thickness  from  a  few  inches  to  36  feet.6  Alluvial  gold  has  been 
found  along  the  gravels  of  the  Wipp  Thai  from  the  Brenner  Pass 
to  Innsbruck. 

Salzburg. — The  gold  mines  of  theLungau  Tauern  chain  lie  on  its 
northern  flanks  at  Schellgaden,  some  four  miles  east  of  St.  Michael, 
and  on  the  northern  side  of  the  upper  Mur  Thai.  Topographically 
and  geologically,  the  country  is  a  continuation  of  the  Hohe  Tauern. 
The  veins  were  extensively  worked  in  past  centuries,  but  have  been 
neglected  in  recent  years.  They  are  essentially  small  quartz- 
lenses  in  a  hornblende-mica-schist  that  passes  with  increase  of 
felspar  to  a  gneissic  rock.  The  lenses  are  disposed  along  a  zone 
after  the  manner  of  quartz-lenses  in  schists,  each  lens  tending  to 
overlap  its  successor.  The  maximum  thickness  and  length  of  the 
lenses  appears  to  be  6  feet  and  185  feet  respectively.  Working  in 
the  winter  is  rendered  difficult,  and  at  times  impossible,  by  the 
avalanches  to  which  the  higher  valleys  and  mountain  slopes  are 
subject.0  The  ores  are  highly  pyritous,  containing  pyrite,  chalco- 
pyrite,  and  galena,  with  rare  blende.     The  tenor  of  the  ore  during 

a  Lowag,  Oesterr.  Zeit.  fur  Berg-  und  Hiitt.,  1901,  XLIX,  p.  415. 

b  Schmitt,  Berg-  und  Hutt.  Zeit.,  1868,  p.  11  ;     Wolfskron,  Oesterr.  Zeit.  fur  Berg- 
und  Hutt.,  XLIII,  1S95,  p.  349. 

c  Beyschlag,  Zeit.  fur  prakt.  Geol.,  1S97,  p.  210. 


164  EUROPE. 

the  last  30  years  (1789-1818)  of  active  working  was  in  gold  5£  dwts. 
(9-2  grams.),  and  in  silver  5  dwts.  (8-9  grams.)  per  metric  ton.ft 
Elsewhere  in  Salzburg  gold  has  been  obtained  from  the  marls  of 
Gastein  in  the  Gastein  Thai,  where  it  is  associated  with  magnetite 
and  garnet  ;  from  pyritous  veins  in  gneiss  at  Bockstein  in  the  same 
valley  ;  from  similar  veins  in  the  Rauris  Thai  and  Fusch  Thai ; 
and  from  the  neighbourhood  of  Zell. 

Carinthia. — The  formerly  important  gold-mines  of  Lengholz, 
near  Steinfeld,  and  of  Siflitz,  near  Lind,  were  discovered  about  1660. 
They  lie  in  the  Drauthal,  near  Sachsenburg.  Their  veins  are  in 
mica-schist  and  gneiss.  Recent  explorations  at  Lengholz  showed 
the  old  workings  to  have  been  driven  on  a  brecciated  vein  cemented 
by  calcite  and  carrying  magnetite  and  chalcopyrite,  together  with 
a  little  mispickel.  The  magnetite  on  assay  carried  6  J  dwts.  of  gold 
and  silver  per  ton.  The  Siflitz  region  lies  north-east  of  Lind.  Its 
gold-quartz  veins  occur  in  phyllite  and  biotite-mica-schist,  and  carry 
a  large  percentage  of  pyrites.  The  adjacent  schists  also  are  im- 
pregnated with  pyrites.  Free  gold  is  found  in  the  veins.6  Auriferous 
gravels  were  formerly  worked  in  Carinthia.  Extensive  remains 
of  ancient  washings  are  found  at  Weisenau,  in  the  Lavant  Thai  in 
the  east  of  the  province.  These  appear  to  have  been  worked 
only  spasmodically  since  1757.  Numerous  heaps  of  pebbles  and 
boulders  testify  to  former  activity.  At  Tragni,  near  Paternion, 
auriferous  gravels  were  formerly  worked  by  shafts  and  levels. 
The  deposits  of  the  Lieser  Thai  are  less  extensive  than  those  of 
the  two  foregoing  localities,  though  gold-washing  in  the  Lieser 
Thai  is  possibly  -of  greater  antiquity,  since  it  is  believed  to  date 
from  the  fourteenth  century,  and  was,  indeed,  the  subject  of 
numerous  edicts  during  the  sixteenth  century.0  Remains  of  ancient 
washings  are  disposed  along  the  valley,  principally  between  Gmiind 
and  Spittal. 

The  veins  of  the  Hohe  Tauern  mountains  on  the  slopes  of  the 
upper  valleys  of  the  Moll,  in  the  extreme  north-west  corner  of 
Carinthia,  were  undoubtedly  worked  in  Roman  times.  They  appear 
to  have  reached  a  period  of  maximum  production  during  the  six- 
teenth century.  The  country  in  the  neighbourhood  of  the  veins  is  a 
complex  of  Archaean  rocks  made  up  of  the  gneisses  and  schists  of 
the  Central  Alps.  The  schists  are  micaceous,  chloritic,  and  cal- 
careous. They  are  traversed  by  extremely  thin  quartz  veins  that 
carry  gold,  both  free  and  associated  with  pyrite.  The  sulphides 
present    are    pyrite,    chalcopyrite,    arsenopyrite,    blende,    galena, 

aPosepny,  Archiv.  fur  prakt.  Geol.,  I,  1879,  p.  155. 

h  Canaval,  Zeit.  fur  prakt.  Geol.,  IX,  1901,  p.  425. 

c  Canaval,  Archiv.  fur  prakt.  Geol.,  Freiberg  in  Sacks.,  II,  1895,  p.  599. 


AUSTRIA.  165 

silver  sulphides,  and  occasional  molybdenite.  Associated  with  the 
veinlets  of  the  Hohe  Tauern  are  auriferous  and  pyritous 
impregnations  of  the  adjacent  rock  walls,  the  whole  forming 
well-defined  lode-channels.  One  such— the  Seiglitz-Pockhart— has 
been  traced  for  nearly  4  miles  along  its  strike.  It  carries  gold  only 
in  the  schists,  becoming  barren  on  passing  into  the  gneiss.  The 
principal  occurrences  are  on  the  southern  slopes  of  the  Hohe  Tauern, 
in  the  Moll,  Fleiss,  and  Zirknitz  valleys.  The  Kloben  and  Gutthal 
mines  in  the  Moll  valley  lie  at  an  altitude  of  9,400  feet  above  sea- 
level.  Very  rich  pockets  were  found  in  the  Rathhausberg  mines  in 
this  vicinity,  in  the  first  half  of  the  eighteenth  century.  The  pockets 
lay  at  a  depth  of  1,300  feet  below  the  surface,  and  were  therefore 
well  within  the  sulphide  zone.  The  tenor  of  the  ore  worked  in  the 
two  principal  mines  of  the  Hohe  Tauern,  viz.,  the  Rathhaus  and  the 
Rauris,  has  steadily  fallen  from  If  ounces  in  the  first  half  of  the 
seventeenth  century  to  8  dwts.  in  the  beginning  of  the  nineteenth 
century.  The  Rauris  mines  were  especially  productive  from  1562 
to  1579.  The  distribution  of  gold  in  the  most  recent  workings  is 
extremely  capricious,  and  the  yield  of  the  whole  group  is,  at  the 
present  time,  unimportant/* 

Bosnia. — As  isolated  historical  records  indicate,  the  gold 
industry  of  Bosnia  was'  in  former  times  of  some  considerable  value 
to  the  Romans.6  It  was  practically  confined  to  working  the 
extensive  placer  deposits,  which  are  both  Recent  and  Pleistocene. 
Some  of  the  latter  are  quite  600  feet  above  the  present  valley-level, 
especially  on  the  slopes  of  the  Fojnica  valley.  In  the  alluvium  of  the 
valleys  of  the  Urbas,  Lasva,  Fojnica,  and  Zeleznica,  traces  of 
the  old  workings  can  still  be  seen,  in  the  form  of  huge  boulder 
heaps  or  prospecting  and  mining  pits.  Similar  traces  of  former 
mining  activity  are  found  in  the  mountains,  in  the  portion  of  these 
old  allu vials  that  lies  above  Fojnica  in  the  Vranitza  mountains. 
Lode-mining  was  carried  on  at  one  spot,  namely,  in  the  decomposed 
pyritous  mass  of  Cervenika,  north-west  *of  the  town  of  Fojnica. 
Further,  there  are,  in  the  Vranitza  mountains,  numerous  traces  of 
ancient  fruitless  prospecting  in  slates  and  quartz-porphyry. 

The  origin  of  the  old  workings  is  to  some  extent  known. 
They  date  from  the  fifth  century  B.C.,  and  were  made  by  the 
ancient  IUyrians,  who,  from  their  knowledge  gained  in  this  work, 
became,  after  the  Roman  occupation  (78  B.C.),  the  best  miners  the 
Romans  possessed.  Old  Roman  coins,  inscriptions,  tombs,  and 
towers  have  been  found  in  the  immediate  neighbourhood  of  the 
old  workings.     In  the  Biela  valley  the  foundations  of  an  old  Roman 

a  Kruscli,  Zeit.  fur  prakt.  Geol.,  1897,  p.  77. 

"  Riicker,  "  Einiges  iiber  das  Gold  Vorkommen  in  Bosnien,"  Vienna,  1896. 


166 


EUROPE. 


furnace  have  been  exposed.  There  are  also  old  aqueducts  in  the 
neighbourhood  of  Fojnica.  The  well-defined  workings  in  the 
alluvial  at  Bistrica,  Gornj-Vakuv,  Kresevo,  and  Fojnica  may  date 
from  the  Middle  Ages.  To  this  period  Riicker  also  ascribes  the 
workings  in  the  pyrites-mass  of  Cervenika.  From  the  great  exten- 
sion of  the  ancient  mining  works  Riicker  concludes  that  Bosnia 
was  a  country  once  rich  in  gold. 

Recent  tests  in  the  alluvium  of  the  Urbas  showed  the  average 
tenor  in  gold  to  be  10  grains  per  metric  ton  ;  in  the  Bistrica  it 
ranges  from  -6  grain  to  31  grains;  and  in  the  neighbourhood  of 
Lasva  from  •  6  grain  to  23  grains,  the  whole  averaging  4  grains  per 
metric  ton.  The  presence  of  gold  in  the  sands  of  the  Narenta, 
Rama,  and  Neretvica  streams  has  also  been  determined.  The 
source  of  the  alluvial  gold  is  doubtless  in  the  Lower  Triassic  rocks 
(Bunt-sandstein),  which,  as  near  Djelilovac,  carry  tenors  of  2|  grains 
gold  per  metric  ton. 

The  sandstones  are  themselves  secondary  deposits,  and  the 
primary  deposit  appears  to  be  that  already  mentioned,  the  Palaeo- 
zoic pyritous  slates  of  Cervenika.  Two  quartz-veins  near  Vilenisa 
and  Heldovi,  not  far  from  Travnik,  carrying  haematite  and 
pyrite,  gave  an  average  on  assay  of  14  dwts.  and  10  dwts.  gold 
per  metric  ton  respectively.  Gold  occurrences  are  also  known  in 
the  ferruginous  beds  of  Varosluk,  south  of  Lisac,  and  also  in  quartz 
veins  west  of  Cehovac,  in  the  Lasva  region. a 

The  gold  production  of  Austria  alone  (not  including  Hungary) 
during  1900  and  the  years  of  the  present  century,  has  been  : — h 


Metric  Tons 
Ore. 

Value. 

Also  produced  at 
Metallurgical  Works. 

Year. 

Kroner. 

Sterling. 

Kg. 
Fine  Gold. 

Value,  Sterling. 

1900 
1901 
1902 
1903 
1904 
1905 
1906 
1907  c 

227 

143 

74 

2,148 

12,653 

35,937 

33,032 

30,710 

42,831 
31,814 
21,140 
105,779 
293,622 
757,523 
675,850 

£1,784 

1,325 

881 

4,407 

12,234 

31,563 

28,137 

71 

47 

7 

8 

71 

204 

126 

142 

£9,691-5 

6,415-5 

955-5 

1,0920 

9,691-0 

27,846-0 

17,202  8 

19,4300 

a  Foullon,  Jahrb.  d.k.k.  geol.  Reichanst.,  XLII,  1892,  pp.  1-52  ;     Katzer,  Oesterr. 
Zeit.  fur  Berg-  und  Hiitt.,  XLIX,  1901,  pp.  277-280. 

°  Statistisclies  Jahrbucli  des  k.k.  Ackerbau-Ministeriums,  Vienna,  1801-1807. 

f  Oesterr.  Statist,  des  Berg.,  1907. 


167 


HUNGARY. 


Three  well-defined  auriferous  districts  are  known  in 
Hungary.  Two  of  these  are  of  comparatively  little  importance. 
The  third,  in  Transylvania,  is  the  chief  gold-producing  district  of 
Europe.  Of  the  two  former,  one  lies  to  the  north  of  Buda-Pesth 
in  the  neighbourhood  of  Schemnitz  (Selmeczbanya)  and  Kremnitz 
(Kormoczbanya),  and  the  other  in  Eastern  Hungary,  near  the  Galician 
frontier.  The  Schemnitz  and  Kremnitz  mines  are  among  the 
oldest  in  Central  Europe,  and  date  probably  from  the  commence- 
ment of  the  Christian  Era.  They  passed  into  the  possession  of  the 
Slavs  in  745  a.d.  The  Schemnitz  mines  in  1690  produced  16,984 
ounces  of  gold,  while  the  production  of  precious  metals  from  1740 
to  1773  is  estimated  at  at  least  70,000,000  gulden.  In  1881  the  annual 
production  of  gold  was  about  16,000  ounces  ;  ten  years  later  it  had 
fallen  to  14,000  ounces.  According  to  B6ckh,a  the  oldest  formation 
in  the  neighbourhood  of  Schemnitz  is  a  Triassic  slate  through  which 
diorites  are  intrusive  as  dykes  and  stocks  that  have  altered  the 
slates  to  mica-schists  and  hornstones  along  their  contacts.  Inter- 
bedded  with  the  slates  is  a  limestone.  Nummulitic  Eocene  shales 
overlie  the  Triassic  beds.  During  the  Lower  and  Upper  Mediter- 
ranean stages  widespread  volcanic  eruptions  here,  as  in  Transyl- 
vania, furnished  tuffs  and  lavas  of  an  andesitic  facies.  The  sequence 
of  volcanic  rocks  has  apparently  been  pyroxene-andesite,  diorite 
and  quartz-diorite,  andesite,  and  finally  rhyolite.  Later,  in  the 
Pliocene  period,  basaltic  eruptions  occurred.  The  rhyolites  are 
the  most  widely-developed  rocks,  and  display  glassy,  perlitic,  and 
pumiceous  varieties.  In  the  vicinity  of  the  ore-bodies  the  volcanic 
rocks  have  undergone  the  usual  propylitic  (grunsteinartig)  meta- 
morphosis, are  in  places  highly  silicified,  and  always  carry  a  high 
percentage  of  pyrites.  The  lodes  of  Schemnitz  occur  in  andesite 
and  rhyolite,  and,  to  lesser  extent,  in  diorite,  while  to  the  south- 
west they  pass  out  of  the  volcanic  rocks  into  Miocene  strata.  They 
are  numerous  and  are  characterised  by  great  width.  They  have 
no  well-defined  walls,  but  often  enclose  large  irregular  fragments  of 
country,  in  which  case  the  ore  occurs  as  the  cementing  material  of 
the  breccia.  The  usual  gangue  is  quartz,  but  with  it  are  associated 
calcite,  brownspar,  rhodochrosite,  siderite,  barytes,  and  gypsum. 
The  sulphides  present  are  galena,  blende,  chalcopyrite,  and  auri- 
ferous pyrite.  These  occur  disseminated  through  a  jasperoid  quartz 
locally  termed  zinopel,  which  probably  owes  its  red  colour  to  the 
presence  of  iron-oxides.  Silver  sulphides  are  also  common.  Free 
gold  is  met  with,  more  particularly  in  the  zinopel.     The  principal 

a  Foldtani  Kozloni,  XXXI,  1901. 


168  EUROPE. 

lodes  are  the  Griiner  and  the  Spital.  The  former  has  been  traced  for 
a  distance  of  nearly  a  mile.  It  varies  in  width  from  6J  to  39  feet 
(2  to  12  m.).  Its  course  is  north-east  and  its  dip  south-east  at  70° 
to  80°.  The  greater  part  of  the  ore-body  is  made  up  of  rhyolitic 
breccia,  highly  impregnated  with  pyrites  and  traversed  by  quartz 
veinlets  containing  galena  and  silver  sulphides.  The  richer  ore 
occurs  in  shoots  that  pitch  south-west  in  the  vein,  and  are  rarely 
more  than  130  feet  in  width  ;  between  the  pay-shoots  the  ore  is 
very  low  in  grade.  The  Spital  lode  is  even  larger  than  the  Griiner. 
It  has  been  traced  for  4-8  miles  (8  km.),  and  may  have  a  total 
length  of  7  miles  (12  km.).  The  lode  is  made  up  of  a  complex 
system  of  veins  and  stringers  that  on  union  may  give  a  total 
working  width  of  16  feet  (5  m.).  The  width  of  the  lode-channel 
reaches  a  maximum  of  120  feet.  The  vein-stone  is  mainly  quartz 
associated  with  rhodochrosite,  calcite,  brownspar,  and  barytes. 
The  ore  is  auriferous,  being  argentiferous  galena,  blende,  chalco- 
pyrite,  and  pyrite,  with  a  little  free  gold  and  occasional  grains  of 
cinnabar. 

At  Kremnitz  (Kormoczbanya),  18  miles  north  of  Schemnitz, 
the  lodes  are  similar  to  those  of  the  latter  place,  and  lie  in  ande- 
sitic  (propylitic)  and  trachytic  rocks.  Two  main  lode-groups  are 
known,  in  each  of  which  the  propylite  rock  is  traversed  by  a  complex- 
network  or  stockwerk  of  veinlets  and  stringers.  The  stockwerks 
extend  for  a  mile  in  length  and  for  half  a  mile  in  width.  The  country 
is  impregnated  with  finely  disseminated  pyrites,  which  increases  in 
quantity  on  approach  to  the  veins  and  fissures.  In  addition  to 
the  sulphides  noted  at  Schemnitz,  stibnite  occurs  in  the  ore  at 
Kremnitz.  In  the  Georg-Sigmund  group,  two  defined  lodes 
(Lettengang  and  Georg-Sigmund)  may  be  made  out.  At 
Hodritsch  auriferous  lodes  occur  in  a  diorite  highly  impregnated 
with  pyrites. 

Nagybanya. — In  Eastern  Hungary,  near  the  Galician  frontier, 
is  situated  the  Nagybanya  group  of  mining  districts,  including 
Nagybanya,  Felsobanya,  Kapnikbanya,  Laposbanya,  Borpatak, 
and  Olah  Laposbanya.0  Mining  in  this  district  dates  back  for 
very  nearly  1,000  years,  the  oldest  record  extant  of  the 
Nagybanya  mines  appearing  in  1086  a.d.  The  veins  are 
in  quartz-trachyte  and  andesite  rocks  that  are  intrusive 
through  Tertiary  strata.  The  chief  lode  in  Nagybanya  is  the 
Kreuzberg,  striking  north  and  south,  and  dipping  west  70° 
to  80°.  It  varies  in  thickness  from  2  to  6  feet.  It  is  without  well- 
defined  walls.  The  gangue  is  quartz,  through  which  auriferous 
pyrite  and  chalcopyrite  with  pyrargyrite  and  argentiferous  fahlore 

a  Skewes,  Min.  Sci.  Press.,  Jan.  11,  1908,  p.  66. 


HUNGARY.  169 

are  disseminated.  The  walls  of  the  veins  are  often  well  silicified. 
Felsobanya  lies  a  few  miles  east  of  Nagybanya.  Its  lodes  are  in  simi- 
lar rocks.  They  are  irregular  in  strike  and  dip,  and  vary  in  thickness 
from  1  to  72  feet,  being,  in  the  latter  case,  rather  lode-channels  than 
lodes.  The  cementing  material  is  quartz  containing  pyrites,  with 
which  are  often  associated  realgar,  stibnite,  blende,  chalcopyrite,  and 
argentite ;  carbonate  and  sulphate  of  lime,  barium,  and  iron  are 
abundant.  At  Kapnikbanya,  still  further  east,  the  lodes  occur 
in  a  conglomerate  that  lies  at  the  junction  of  propylite  and  gray 
trachyte.  The  vein-stone  and  general  characteristics  of  the  lodes 
are  similar  to  those  of  Felsobanya.  Large  vughs  are  found  in  the 
Kapnik  lodes,  and  are  often  drusy  with  crystallized  minerals. 

Transylvania. — The  auriferous  deposits  of  Transylvania  lie 
in  the  south-eastern  portion  of  the  Bihar  mountains.  Both  geo- 
graphically and  geologically  the  boundaries  of  the  region  are  sharply 
defined  ;  in  the  north  by  the  valley  of  the  Aranyos,  on  the  east  and 
south  by  the  Maros,  and  on  the  north-west  by  the  White  (Feher) 
Koros.  On  the  south-west  the  geographical  and  geological  boun- 
daries are  not  distinct.  An  irregular  quadrangle  enclosed  by 
lines  drawn  from  Offenbanya  to  Korosbanya,  from  Korosbanya 
to  Nagyag,  from  Nagyag  to  Zalatna,  and  from  Zalatna  to  Offen- 
banya, will  enclose  nearly  all  the  Transylvanian  gold  mines. 

Of  the  early  history  of  the  gold  workings  of  this  region  we  have 
but  little  definite  information,  but  it  is  certain  that  before  the  time 
of  the  Emperor  Trajan  the  Romans  had  already  carried  on  exten- 
sive work  on  the  gold  veins.  Even  at  the  present  day  the  remains 
of  their  quarries  and  levels  may  be  traced  without  difficulty,  and 
are  at  times  of  a  magnitude  so  great  as  to  excite  astonishment  in 
the  mind  of  the  modern  engineer.  Numerous  legends  have  grown 
up  and  are  even  now  current  in  the  country  concerning  the  dis- 
covery or  the  production  of  the  more  famous  deposits.  It  is  related, 
for  example,  that  the  rich  veins  of  Nagyag  were  discovered  through 
the  instrumentality  of  an  Armenian  who  declared  that  he  had  seen 
an  ignis  fatuus  hovering  over  the  outcrop  of  the  fissure.  After 
several  years  of  fruitless  working  on  this  spot  the  gold- tellu ride  veins 
that  have  rendered  the  Nagyag  field  so  famous  were  eventually 
disclosed. 

The  fundamental  rocks  of  the  region  are  Archaean.  These 
are  probably  to  be  correlated  with  the  mass  of  the  Bihar  mountains 
on  the  north,  and  with  the  rocks  of  the  spurs  of  the  Transylvanian 
Alps  across  the  Maros  on  the  south.  The  Archaean  rocks  are  well 
exposed  in  the  north-east,  and  in  the  region  near  Offenbanya 
where  they  occur  as  gneiss,  mica-schist,  and  limestone.  Near 
Toplicza  and  Vormaja  in  the  south,  minor  exposures  of  Archa?an 


170 


EUROPE. 


phyllites  are  found.  Overlying  the  Archaean  rocks  are  widespread 
Jurassic  strata  (Klippenkalk  or  Stramberger  Kalk),  with  which  is 
associated  an  apparently  contemporaneous  melaphyre.  These  rocks 
are  well  developed  throughout  the  Erzgebirge.  By  far  the  greater 
part  of  the  surface  of  the  region  is  formed  by  Carpathian  (Creta- 


5k\\\\\\\\Y 


Fig.  76.     Generalized  Sketch  Map  of  the  Geology  of  the  Tkansylvanian  Auriferous  Region. 

1.  Archaean  schist  and  gneiss.      2.  Melaphyre  and  Jurassic  limestone.     3.  Carpathian  sandstone. 
4.  Tertiary  sediments  and  tuffs.     5.  Tertiary  eruptive  rocks. 

ceous)  sandstones.  Through  all  these  rocks  there  were  erupted  in 
Tertiary  times  the  andesites,  dacites,  trachytes,  and  allied  rocks 
(both  as  tuffs  and  as  solid  flows)  that  have  been  so  closely  con- 
nected with  the  genesis  of  the  auriferous    deposits.     The  general 


HUNGARY.  171 

disposition  of  the  foregoing  beds  is  shown  on  the  accompanying 
geological  sketch  map  (Fig.  76).  From  it  the  predominance  at 
the  surface  of  the  Cretaceous  and  Jurassic  rocks  will  be  apparent. 
In  describing  the  various  more  or  less  isolated  Transylvanian 
goldfields  those  in  the  north-east  will  be  first  taken,  followed  by 
those  occurring  in  successive  order  to  the  south-west. 

Offenbanya. — At  Offenbanya,  situated  on  the  Aranyos  river 
in  the  extreme  north-east  of  the  auriferous  region,  the 
Tertiary  eruptives  rest  on  garnet-  and  staurolite-bearing  mica- 
schists.  In  former  days  crystalline  limestone  adjacent  to  the 
igneous  rocks  carried  rich  pockets  of  gold,  but  these  have 
long  been  exhausted.  The  particular  country  of  the  gold  veins 
is  a  propylitised  dacite.  To  the  west  and  south  of  the  propyli- 
tised  area  there  occurs  a  normal  unaltered  dacite,  while  on  the 
margin  of  the  quartz-bearing  andesites  (dacites)  are  developed 
the  hornblende-andesite  of  the  Coltului  Lazar,  Piatra  Capri,  and 
Cartia  Carolu  mountains.  The  productive  mines  lie  entirely 
beneath  the  Dialu  Ambrului  and  Dialu  Wunet  mountains.  The 
oldest  and  the  most  extensive  workings  lie  in  the  Valea  Boji,  branch- 
ing off  from  the  interior  of  the  Segengott  Level,  which  commences 
in  the  mica-schist,  passes  through  a  breccia  of  mica-schist  and  dacite 
fragments,  and  finally  enters  the  propylitised  dacite.  Owing  to 
the  closing  of  the  older  levels  the  relations  of  the  auriferous  deposits 
to  the  enclosing  country  are  not  now  very  clear.  The  mica-schist 
never  carries  auriferous  veins,  and  these  are  found  here  either 
in  dacite  or  as  stockwerk  replacements  in  crystalline  limestone. 
The  veins,  however  occurring,  are  always  very  thin.  They  have 
been  divided  by  Semper,  according  to  the  vein-filling,  as  follows  : — 

(1)  In  the  south  (Franzisci)  area  :  Native  gold  veins. 

(2)  In  the  central  area  :    Native  gold  and  gold-telluride  veins. 

(3)  In  the  south  :   Telluride  veins. 

The  gold-veins  of  the  first  group  were  not  known  in  the  upper 
levels,  and  were  first  met  with  in  the  contact-breccia  between  the 
mica-schist  and  the  dacite.  Their  vein-filling  is  pyritous  quartz 
carrying  free  gold  in  wires,  plates,  and  strings.  The  pyrite  of  the 
adjacent  country  is  also  more  or  less  auriferous. 

The  boundary  between  the  gold  veins  and  the  gold-telluride 
veins  is  a  brecciated  fissure  (the  Widersinnige  Kluft)  that  crosses  the 
veins.  The  gold  veins  are  developed  on  the  foot-wall,  the  gold- 
telluride  veins  on  the  hanging- wall  of  the  fissure.  The  matrix  of  the 
latter  veins  is  quartz  with  occasional  calcite,  containing  tetrahedrite, 
free  gold,  and  telluride  ores ;  as  a  rule,  the  gold-telluride  ores  are  not 
of  high  tenor.  The  third,  or  telluride  type  of  veins,  comprises  five  main 
lodes,  and  a  network  of  smaller  veinlets.     The  latter  are  exceedingly 


172  EUROPE. 

thin,  and  carry  gold  tellurides  (sylvanite  and  nagyagite),  accompanied 
by  blende,  bournonite,  tetrahedrite,  and  pyrargyrite.  The  matrix 
is  quartz,  calcite,  and  rhodochrosite. 

At  the  contact  of  the  limestone  and  the  dacite,  ore-bodies 
occur  in  cavities  within  the  limestone.  The  gangue  is  here  a  brec- 
ciated  rock  carrying  auriferous  pyrite,  argentiferous  galena,  arseno- 
pyrite,  &c.  In  these  limestones  numerous  traces  remain  of  former 
activity  in  mining.  The  general  outstanding  feature  of  the  gold 
veins  of  Offenbanya  is  the  diminution  in  the  tenor  of  the  ore-bodies 
with  increase  in  depth. 

Verespatak. — The  village  of  Verespatak  lies  about  6  miles  north- 
east of  Abrudbanya  in  the  upper  Valea  Rosia  valley,  which  is  bounded 
on  the  north-east  and  on  the  south-east  by  ranges  of  high  andesitic 
mountains,  on  the  south  by  the  greater  and  lesser  Kirnik  and  the 
Boj  mountains,  and  finally  on  the  west  by  mountain  ridges  of  the 
Carpathian  sandstones.  The  Verespatak  complex  is  composed  of 
several  successive  Tertiary  eruptions  that  have  broken  through  the 
Carpathian  sandstones  and  have  formed  mountain  peaks  and  ranges. 
The  important  mines  of  the  region  lie  in  the  eruptive  rocks  of  the 
greater  and  lesser  Kirnik  and  of  the  Boj.  These  rocks  are  pene- 
trated by  the  Orlau  level,  the  mouth  of  which  is  in  the  Valea  Rosia 
valley,  about  1 J  miles  west  of  the  auriferous  veins.  Eastward  from 
the  mouth  the  tunnel  passes  through  2,328  feet  (710  m.)  of  Car- 
pathian sandstones,  then  through  5,445  feet  (1,660  m.)  of  the  Tertiary 
conglomerates,  termed  by  Posepny  the  "  Local  Sediments,"  and 
finally  through  1,738  feet  (530  m.)  of  a  second  band  of  Carpathian 
sandstone.  From  this  tunnel  the  principal  mines  have  been  worked. 
To  the  north  of  it  the  Orlau  cross-cut  was  driven  in  the  Local 
Sediments  until  beneath  the  andesite  of  the  Gypele  mountain. 
To  the  south,  the  dacite  of  Boj  was  met  with ;  this  rock  in  its  eastern 
portion  carried  one  of  the  most  famous  of  the  stockwerks  of  Veres- 
patak (the  Katroneza).  The  eruptive  rocks,  though  differing  con- 
siderably in  local  characters,  are  apparently  nevertheless  all  products 
of  differentiation  from  a  single  dacite  magma.  Rhyolites  with  a  pumi- 
ceous  ground-mass  form  the  cementing  material  of  the  breccias  of  the 
summit  of  Boj  and  also  of  those  found  in  the  east  of  the  Katroneza 
level.  In  the  Csetatye  cross-cut  the  rhyolite  appears  as  the  grey 
cementing  material  of  a  breccia  that  is  largely  made  up  of  fragments 
of  Carpathian  sandstone,  Archaean  rock,  dacite,  and  white  rhyolite. 
The  Local  Sediments  filling  the  real  valley  basin  of  Verespatak, 
and  occurring  also  in  the  Korna  stream  to  the  south  of  the  Kirnik 
mountains,  show  distinct  stratification.  They  are  composed  partly 
of  conglomerate  and  partly  of  soft  clayey  cementing  matter  enclosing 
scattered  blocks  of  the  older  rocks.  The  sediments  are  in  many 
places  overlain  by  dacite. 


HUNGARY.  173 

Closely  akin  to  the  Lower  Tertiary  conglomeratic  Local 
Sediments  is  a  peculiar  rock  locally  designated  glamm.  It  is  a 
completely  unstratified  breccia  of  a  grey  or  grey-black  colour,  in 
which  a  clayey  matrix  carries  angular  fragments  of  Carpathian 
sandstone,  mica-schist,  phyllite,  and  Tertiary  eruptive  rocks.  The 
cement  of  the  glamm  is  impregnated  with  exceedingly  finely-divided 
pyrite.  The  glamm  is  especially  well  pyritised  at  its  contact  with 
dacite.  Its  passage  into  the  Local  Sediments  is  gradual, 
whereas  its  boundary  with  the  dacite  is  always  sharply  defined. 
Its  thickness  is  on  an  average  between  45  and  50  feet,  where  met 
with  on  the  boundary  between  the  northern  Local  Sediments 
and  the  dacite.  It  surrounds  the  dacite  and  the  rhyolite  of  the 
Boj  and  of  the  Kirnik  mountains  as  a  narrow  border  in  the  north 
and  a  broad  one  in  the  south.  Semper,a  who  has  devoted  a  con- 
siderable amount  of  attention  to  the  subject,  and  from  whose  descrip- 
tion most  of  the  following  details  are  derived,  assumes  that  the  glamm 
has  been  formed  by  a  sudden  upward  outwelling  of  mud  that  broke 
off  numerous  fragments  of  Archaean,  Cretaceous,  and  Tertiary 
rocks  in  its  passage  through  the  underlying  rocks,  and  carried  them 
to  the  surface. 

The  general  relations  of  the  Verespatak  strata  are  expressed 
by  the  following  upward  succession  :  Carpathian  sandstone,  true 
rhyolite,  glamm,  Local  Sediment,  younger  rhyolite  with  pumiceous 
ground-mass,  and  finally  hornblende-andesite. 

The  gold  veins  lie  indifferently  in  the  dacite  of  the  Boj  and 
Kirnik  mountains,  in  the  Local  Sediment,  and  in  the  Carpathian 
sandstone.  Payable  mines  occur  neither  in  the  hornblende- 
andesite  nor  in  the  glamm.  On  the  whole  the  most  favourable 
rocks  appear  to  be  the  highly-weathered  and  pyritised  dacite  and 
older  rhyolite.  The  vein-filling  shows  occasionally  a  laminated 
and  banded  structure.  It  is  generally  quartz  with  calcite  and 
rhodochrosite,  impregnated  with  auriferous  pyrite  or  with  free  gold. 
Quartz  with  pyrite  and  black  alabandite  (Mn  S)  is  not  uncommon, 
Chalcopyrite,  fahlore,  galena,  and  tetrahedrite  are  met  with  more 
generally  in  the  silver  lodes  of  the  district  than  in  the  gold 
veins.  Stockwerks  are  a  characteristic  feature  of  the  Verespatak 
gold  deposits.  They  are  formed  by  the  close  interlacing  of  a  great 
number  of  veins  and  veinlets.  In  their  neighbourhood  the  highly 
propylitised  country-rock  is  silicified  and  pyritised.  As  a  rule, 
stockwerks  are  developed  in  those  eruptive  breccias,  of  which  the 
cement  is  the  above-mentioned  porous  pumiceous  rhyolite  impreg- 
nated  with    secondary   silica    and    with    auriferous    pyrite.     The 

a  "  Beitrage  zur  Kenntniss  der  Goldlagerstatten  des  Siebenbiirgischen  Erzgebirges," 
Abhand.  der  Kon.  Freuss.  geol.  Landesanst.,  XXXIII,  1900,  p.  146. 


174  EUROPE. 

famous  "  Katroneza  Stock  "  is  a  brecciated  stockwerk  forming  a 
chimney  in  the  dacite.  Its  cementing  material  was  largely  quartz 
and  pyrite  that  carried  finely-divided  native  gold.  As  in  the 
majority  of  the  Transylvanian  ore-deposits,  the  tenor  of  the  ore 
steadily  decreases  in  depth.  The  richer  parts  appear  to  be  the  central 
portions  of  the  stockwerks.  Another  well-known  ore-body  is  the 
"  Csetatye-Stock,"  which  is  formed  of  a  close  network  of  fissures 
and  veinlets  reticulating  the  dacites,  Local  Sediments,  and  Car- 
pathian sandstone  of  the  Boj  Hill. 

In  the  Local  Sediments  the  gold  veins  are,  as  a  rule,  small, 
but  regular.  The  ores  are  auriferous  pyrite  and  free  gold  lying  in 
quartz  matrix  that  is  occasionally  associated  with  calcite.  The 
number  of  veins  in  these  beds  is  relatively  much  smaller  than  in 
the  dacite  and  rhyolite.  The  workable  veins  in  the  Carpathian 
sandstone  are  of  very  little  importance.  They  follow  the  regular 
strike  and  dip  of  the  strata  ;  their  filling  is  quartz,  calcite, 
auriferous  pyrite,  free  gold,  and  more  rarely,  galena,  blende, 
marcasite,  and  chalcopyrite. 

As  a  rule,  the  walls  of  the  veins,  for  a  distance  within  the 
country  of  at  least  a  foot,  are  generally  worth  milling.  Stockwerk 
deposits  have  occasionally  been  found  in  the  Carpathian  sand- 
stone near  its  contact  with  the  Local  Sediment.  Of  these  the 
"  Letyeer-Stock  "  has  been  the  richest. 

The  gold  of  Verespatak  occurs  crystallized  in  vughs,  free  in  the 
quartz,  or  associated  with  pyrite.  Its  fineness  is  only  about  500. 
The  dacites  and  rhyolites  carry  more  auriferous  sulphide  ore  and 
less  free  gold  than  the  Local  Sediment.  The  richness  of  the  deposits 
is  directly  proportional  to  the  degree  of  silicification  of  the  rock.  The 
general  rules  applying  to  the  Transylvanian  mines,  viz.,  that  the 
richness  of  a  deposit  is  largely  dependent  on  degree  of  alteration, 
on  thickness  of  vein,  on  intersection  of  veins,  &c,  are  also  applic- 
able to  the  Verespatak  deposits.  It  is  worthy  of  note  that  galena 
is  locally  considered  to  indicate  poverty  of  ore.  The  upper  work- 
ings yield  much  more  vugh-gold  than  is  found  at  depth,  but  the 
deeper  levels  nevertheless  still  furnish  rich  pockets  of  crystallized  gold. 

In  the  Korna  and  Bucsum  valleys,  a  few  miles  south-east  of 
Verespatak,  Jurassic  limestones  and  Carpathian  sandstones  are 
intruded  and  covered  by  Tertiary  andesites,  dacites,  and 
volcanic  breccias.  In  bygone  centuries  a  flourishing  mining 
industry  was  conducted  in  these  valleys  ;  in  the  Bucsum  valley  at 
the  Concordia  mine,  rich  deposits  were  found  at  the  intersection 
of  vertical  and  flat  fissures.  The  gangue  of  the  veins  is  calcite 
and  the  country  is  a  siliceous  contact-breccia."     In  all  respects  the 

a  Gesell,  Jahrsber.  der  kon.  Ungarischen-  Geol.  Anstalt.,  1899,  pp.  97-103. 


HUNGARY 


175 


general  characters  of  the  mines  of  these  valleys  are  similar  to  those 
of  Verespatak  and  require,  therefore,  no  further  mention  in  this 
place. 

A  few  miles  south  of  Bucsum  there  lies  a  small  group  of  mines 
in  the  neighbourhood  of  Botes,  Vulkoj,  and  Korabia.  The  peak 
of  Botes  (Dialu-Botesiu,  1,362  m.)  is  connected  with  the  Korabia 
range  by  a  low  saddle  composed,  as  indeed  is  the  mountain  itself, 
of  younger  Carpathian  sandstone.  The  veins  of  the  area  traverse 
a  micaceous  sandstone.     They  are  from  4  inches  to  3  J  feet  in  thick- 


Figs.  77  and  78. 

Fig.  77.  N.-S.  section  through  Vulkoj  Mines  [Posepny).  Fig.  78.  E.-W.  section' through  Botesiu 
and  Vulkoj. 

A.  Botesiu  ;  B.  Vulkoj ;  b.  Sandstone  ;  c.  Andesite  ;  a.  Nepomuk  adit;  d.  Korabia  openwork. 
iugs  ;    ;'.  Jeruga  vein. 

ness,  and  strike  approximately  at  right-angles  to  the  country.  Their 
underlie  is  very  steep  (70°  to  75°  to  the  west).  The  vein-stone  is 
quartz  associated  with  pyrite,  chalcopyrite,  galena  and  blende, 
the  sulphides  occurring  either  as  deposits  contemporaneous  with  the 
quartz,  or  as  a  later  deposition.  Free  gold  is  not  uncommon; 
enrichments  containing  it  occur  at  intersections  and  are  generally 
denoted  by  a  cherty  gangue  containing  hessite. 

On  the  north-east  slope  of  the  Korabia  mountains,  numerous 
veins  are  worked.     These  occur  exclusively  in  the  andesite  or  at  its 


176  EUROPE. 

contact  with  the  micaceous  clay-slates  and  Carpathian  sandstone. 
The  vein-stone  in  this  case  is  composed  of  quartz  or  calcite,  with 
pyrite  and  some  blende,  galena,  and  free  gold.  The  tenor  of  the 
sulphide  ore  varies  from  J  to  \  ounce  (7  to  15  grams.)  per  ton. 
Posepny a  shows  that  the  veins  of  Vulkoj  and  Botes  have  a  common 
origin,  and  are  merely  developed  in  different  rocks.  The  mines  of 
this  region  were  formerly  very  profitable,  but  the  industry  is  now 
on  the  point  of  extinction.  As  a  general  rule,  the  veins  are  im- 
poverished on  passing  from  the  igneous  rocks  to  the  underlying 
sedimentaries. 

Between  Zalathna  and  Sztanizsa  there  runs  the  lofty  north- 
west and  south-east  range  of  the  Grohasel  mountains,  trending 
from  about  2  miles  south  of  the  village  of  Sztanizsa  to  the  south  of 
Zalathna,  a  distance  of  some  12  miles,  with  a  width  over  this 
length  of  2  to  6  miles.  The  basement  rock  beneath  the  andesite  is 
the  Carpathian  sandstone.  In  the  south  and  south-east  it  is  bounded 
by  the  melaphyre  range  in  the  neighbourhood  of  Porkura,  and  by 
the  older  Miocene  sediments  of  the  Almas  valley.  Payable  gold  and 
gold-tellurium  veins  have  been  worked  on  the  north-west  slopes  of 
Fericsel  and  of  Vurfu  Ungeri  (Sztanizsa)  ;  in  the  valley  between 
Fericsel  and  Vurfu  Negri  (Tekero)  ;  on  the  eastern  slojDes  of  the 
Grohasel  mountains  (Faczebaj)  ;  and  also  in  the  neighbourhood 
of  Nagy almas. 

Faczebaj. — At  Faczebaj  the  Grohasel  mountains,  the  main 
ranges  of  the  central  auriferous  area,  are  composed  of  hornblende- 
andesite.  From  their  eastern  slopes  minor  spurs  composed  of 
Carpathian  sandstone  are  thrown  off  and  are  traversed  by  gold- 
quartz  lodes.  The  sedimentary  strata  here  strike  north  and  south 
and  dip  west.  The  veins  also  strike  north  and  south,  but  their 
dip  is  to  the  east  at  varying  angles.  Their  thickness  varies  from 
less  than  an  inch  to  less  than  a  foot,  and  they  are  much  faulted 
both  in  hard  and  soft  rocks.  The  gangue  mineral  is  quartz, 
which  is  often  chalcedonic.  Native  gold  occurs  crystallized  in 
octahedra,  and  also  as  moss  gold  ;  combined  it  is  found  with 
and  in  pyrite,  native  tellurium,  tetrahedrite,  chalcopyrite,  bornite, 
dyscrasite,  bismuthinite,  galena,  malachite,  marcasite,  pyrrhotite, 
realgar,  stephanite,  and  tellurite.  The  fineness  of  the  free  gold  is 
often  more  than  930.  Enrichments  are  found  where  silicified 
country  is  adjacent  to  a  quartz  vein,  and  seldom  occur  in  the 
softer  rocks.  The  average  value  of  the  ore  extracted  averages 
some  5  dwts.  gold  per  ton. 

Veins  are  also  worked  in  the  hornblende-andesite  of  the 
Breaza   mountains  lying   to   the    south-west  of   Zalathna.      These 

a  "  Genesis  of  Ore  Deposits,"  Trans.  Amer.  Inst.  M.E.,  XXIII,  1894,  p.  276. 


HUNGARY. 


177 


carry  the  same  minerals  as  are  found  in  the  veins  of  the  Car- 
pathian sandstone  of  Faczebaj,  indicating  thus  a  close  genetic  rela- 
tionship with  them,  and  with  the  veins  of  the  Grohasel  mountains. 

The  veins  of  Nagyalmas,  a  short  distance  to  the  south  of 
Faczebaj,  are  of  no  great  present  importance.  They  lie  in  a  breccia 
at  the  contact  of  hornblende-andesite  and  Carpathian  sandstone. 
Leaves  and  plates  of  free  gold  occur  in  a  quartzose  and  calcific 
matrix.  Gold  is  also  found  in  a  state  of  fine  division  associated 
with  other  ores,  and  more  especially  with  stibnite,  in  which  case 
the  ore  may  reach  a  tenor  of  20  ounces  gold  per  ton.  The  gold  is 
of  an  average  fineness  of  650. 

The  hornblende-andesite  of  Fericsel  and  Sztanizsa  (Vurfu 
Ungeri)  is  decomposed  in  the  immediate  neighbourhood  of  the 
veins  to  propylite  (grunsteintrachyte).  Its  numerous  veins  are  poor 
and  unprofitable.  At  Tekero  the  slopes  of  the  valley  are  melaphyre, 
in  which  are  numerous  exploratory  workings.  The  veins  along 
which  search  for  gold  has  been  made  lie  in  highly  altered  melaphyre 
rock.     They  are  only  2  inches  to  3  inches  wide,  and  carry  a  pre- 


Fig.  79.     Ideal  cross-section  through  the  Nagyag  Mountains  (V.  Inkey). 
a.  Phyllite.     b.  Lower  Miocene  sediments,     c.  Pronylitised  rock.    d.  Normal  dacite.    e.  Kaolinised 
zones.     /.  Surface  weathering,     g.  Vein  zones. 


dominantly  calcific  gangue  with  occasionally  a  little  quartz  and  free 
gold,  auriferous  pyrite,  chalcopyrite,  and  blende.  Crystallized  gold 
of  later  deposition  occurs  in  vughs  in  the  veins,  but  the  greater  part 
of  the  gold  is  associated  with  pyrite,  forming  an  ore  so  refractory 
that  the  ordinary  amalgamation  process  cannot  be  employed  for  the 
recovery  of  the  gold.  Beyond  Tekero  numerous  veins  lie  in  andesite 
and  furnish  small  mines. 

Nagyag.—  The  auriferous  veins  of  Nagyag  are  probably  among 
the  best  known  of  those  of  Transylvania.  They  lie  in  the  extreme 
southern  corner  of  the  quadrangular  auriferous  area  outlined  at  the 
beginning  of  this  section.  Nagyag  itself  lies  on  the  northern  slopes 
of  the  watershed  of  the  Maros.  The  bed-rock  of  these  mountains  is 
Archsean  clay-slate,  on  which  have  been  deposited  Mesozoic  strata, 
now  only  locally  preserved,  and  of  little  importance.     In  the  imme- 

M 


178 


EUROPE. 


W&i 


diate  vicinity  of  the  Nagyag  veins  Lower  Miocene  shales,  sandstones, 
and  conglomerates  form  the  basement  rocks  on  which  are  deposited 
great  flows  of  dacite  and  hornblende-andesite.  The  latter  rock, 
which  is  rich  in  augite,  carries  no  gold-quartz  veins,  and  the 
universal  country  of  the  ore-bodies  is  a  quartz-bearing  dacite, 
particularly  when  it  has  undergone  extensive  propylitisation,  a 
pathological  feature  which,  indeed,  is  generally  characteristic  of 
the  country  of  the  ore-bodies  of  the  Transylvanian  auriferous  region. 
The  process  of  propylitisation  extends  outward  from  the  veins,  and 
appears  to  arise  from  the  passage  of  the  solf ataric  waters  that  have 
presumably  also  furnished  the  vein-filling. 

Independently    of     the 
fissures    induced    in  various 
ways  at  the  former  surface, 
there   may  be  distinguished 
in  the  dacite  of  Nagyag  three 
kinds  of  fissures,  viz.,  glauch 
veins,  ore-bearing  veins,  and 
barren  "  pug  "   (clay)  veins. 
The  glauch  veins  are  charac- 
teristic  of   Nagyag.       Their 
filling  is  a  soft  clayey  mass 
of  dark  grey  colour,  in  which 
are  usually  contained  brec- 
ciated    fragments  of  dacite, 
sandstone,     and     shale,     or 
more  rarely,  of  phyllite  and 
mica-schist.     The  fragments 
occur   in  extremely  variable 
size     and     quantity.      They 
may    be    considered    to    be 
fault-breccias  in    which  the 
larger  material,    as  well    as 
the  finer,  is  derived  from  the  crushed  country  walls  of  the  fissures. 
Their  thickness  varies  considerably.     They  may  be  thin  as  leaves 
or  may  be  yards  in  width.     Throughout  their  mass  there  is  generally 
disseminated  an  abundance  of  finely-divided  pyrite,  to  which,  indeed, 
the  dark  colour  of  the  glauch  is  probably  due.     They  traverse  not 
only  the  dacite,  but  also  the  Tertiary  sandstones  and  conglomerates. 
On  the  whole,  they  are  developed  apparently  in  close  proximity  to 
the  ore-bodies,  on  which  they  appear  to  exercise  a  favourable  in- 
fluence. 

The  association  of  tellurium  and  gold  is  also  characteristic  of 
the  Nagyag  veins.  Nagyagite  is  the  principal  telluride,  while  sylvanite 


Fig.  80. 

d.  Dacite 
Glauch  vein,  g 


Glauch  Veins,  Nagyag  (F.  Jnkey). 
fir'jr1.  Oldest  Glauch  veins,    g-.  Second 
Youngest  Glauch  vein,  6in.  thick. 


HUNGARY. 


179 


is  much  less  common.  Petzite  and  krennerite  are  rare.  The 
chief  sulphides  are  pyrite,  chalcopyrite,  galena,  and  blende.  Native 
gold  is  rarely  seen,  and  when  visible  is  of  secondary  origin  and  arises 
from  the  decomposition  of  the  tellurides. 

According  to  Von  Inkey,  the  following  succession  of  minerals 
within  the  vein-fissures  may  be  made  out  : — 

(1)  Quartz  (earliest,  but  also  occurs  in  later  formations). 

(2)  Sulphides    (alabandite,     galena,    blende,    fahlore,    pyrite, 

chalcopyrite,  bournonite). 

(3)  Tellurides  and  gold. 

(4)  Calcite. 

(5)  Stibnite,  arsenic,  barytes,  gypsum,  and  realgar. 
The  veins  in  the  dacite   are    richest 

when  they  are  of  medium  thickness  ; 
they  are  clearly  defined  in  the  propyli- 
tised  country.  Great  thicknesses  of  silica 
are  met  with  in  brecciated  zones,  and  are 
always  associated  with  the  above-men- 
tioned alteration  of  the  dacite.  The  veins 
are  continued  into  the  sedimentary  rocks, 
but  the  latter  are  ordinarily  considered  in 
Nagyag  to  be  unfavourable  for  ore-deposi- 
tion. On  the  other  hand,  rich  ore-bodies 
are  found  in  veins  lying  along  the  contact 
of  the  dacite  and  the  sedimentary  rocks. 
Experience  has  shown  that  at  the  inter- 
section of  veins,  deposits  of  increased  rich- 
ness maybe  expected  to  be  found.  Similar 
enrichments  are  met  with  near  the  point 
of  departure  of  stringers,  hangers,  or 
droppers  from  a  main  vein.  It  is  noted 
that  enrichments  are  more  frequent  when 
the  angle  of  intersection  is  acute  (20°  t-o  40°).  The  actual  vein 
crossings  at  Nagyag  are  themselves  generally  rather  poor, 
and  the  rich  ore  is  found  at  a  little  distance  (a  few 
feet)  from  the  actual  intersection.  Often  the  connection  between 
the  two  frayed  or  broken  ends  of  a  transverse  vein  is 
made  by  numerous  small  stringers  that  cross  the  main  vein.  The 
intersection  or  junction  of  two  veins  of  unequal  thickness,  or  the 
contact  of  a  vein  with  the  glauch,  are  regions  of  local  enrichment. 
Great  help  in  the  search  for  rich  veins  is  afforded  by  the  stockwerks 
of  minute  pyrite-stringers  (kiesschnure).  Between  these  pyritous 
stringers  the  dacite  itself  is  always  strongly  impregnated  with 
pyrite.     The  thickness  of  the  pyrite  veinlets  is  often  microscopical, 


Fig.  81.  Enrichment  at  Junction 

of  Pyritous  Veins  and 
"Glauch"  Vein,  Nagyag  (Semper). 

d.  Dacite.  e.  Barren  vein  (Longin- 
hlujt).  k.  Pyritous  stringers. 
g.  Glauch  vein.  e1e1.  Enrichment. 


180  EUROPE. 

but  local  experience  has  shown  that-  at  the  contact  with  the  ore 
veins,  or  at  their  intersection  by  such  pyritous  bands,  the  richest 
deposits  are  found.  Blende  and  alabandite  (Mn  S)  are  con- 
sidered unfavourable  "  indicators,"  while  a  large  body  of  quartz, 
often  indicates  a  high  value.  For  Nagyag  an  absolute  diminution 
in  the  gold  tenor  in  depth  cannot  certainly  be  made  out.  Special 
enrichment  at  any  given  zone  has,  on  the  other  hand,  not  been 
observed. 

The  gold-quartz  veins  of  Hondol,  lying  north-west  of  Nagyag, 
traverse  propylitised  quartz-free  hornblende-andesite.  The  adja- 
cent dacite  of  the  Beszerikucza  mountain  ridges  is,  however,  quite 
unaltered,  and  carries  no  ore-deposits  of  value.  Many  of  the 
mines  of  Hondol  are  very  ancient  ;  of  these  the  Maria-Regina  has 
been  the  most  productive,  whilst  the  Karoli  has  for  many  centuries 
been  famed  for  its  free  gold. 

To  the  west  and  north-west  of  the  above-mentioned  dacite  the 
mountain  range  is  composed  of  hornblende-andesite.  Towards  its 
south-western  end  and  more  especially  at  Toplicza  and  Magura, 
under  the  heights  of  the  Fourazberges  at  Csertes,  are  numerous  re- 
mains of  ancient  gold  mines.  The  western  ridge  of  this  andesite 
massif  is  in  contact,  to  the  east  of  Fuzesd-Barbara,  with  the  mela- 
phyre  of  the  Boicza  mountains.  On  the  slopes  of  Mala,  Piczegus, 
Hunk,  &c,  are  a  number  of  unimportant  mines,  whose  veins  lie 
indifferently  in  the  melaphyre  and  in  the  hornblende-andesite. 
They  are  worked  by  Wallachian  lessees  or  by  small  companies. 
The  combined  gold-districts  of  Tresztya,  Troicza,  and  Barbara, 
lying  a  little  further  to  the  north-west,  are  of  much  more  importance. 
The  principal  workings  in  the  Fuzesd  valley  radiate  from  the  Grimm 
tunnel  which  traverses  Miocene  strata  for  984  feet,  and  then 
passes  through  melaphyre  tuff,  then  through  a  melaphyre  flow, 
meeting  at  1,968  feet  (600  metres)  from  its  mouth  the  first  gold 
vein  (Antonien).  Further  to  the  east,  within  the  tunnel,  the  gold- 
quartz  veinlets  are  close  together,  and  the  alteration  of  the  mela- 
phyre is  more  advanced.  The  melaphyre  is  decomposed  to  form  a 
kaolin-calcite  product.  Veins  are  also  found  in  the  hornblende- 
andesite.  Along  the  Grimm  tunnel  the  veins  strike  north  and  south, 
parallel  indeed  to  the  contact  of  the  melaphyre  and  the  hornblende- 
andesite.  The  width  of  the  veins  is  rarely  more  than  4  inches. 
The  gangue  is  quartz  and  calcite.  Free  gold  is  associated  with 
pyrargyrite,  stephanite,  fahlore,  bournonite,  chalcopyrite,  pyrite, 
marcasite,  galena,  blende,  and  stibnite.  The  greater  part  of  the 
auriferous  content  is,  however,  enclosed  in  pyrite.  The  tenor  of 
the  ore  is  from  3  to  33  dwts.  (5  to  50  grams)  gold  and  silver  bullion 
per  metric  ton.    Silver  ores  are  restricted  more  particularly  to  the 


HUNGARY.  181 

Troicza  district.  The  relation  between  the  tenor  of  the  quartz 
and  its  country  walls  resembles  much  that  obtaining  at  Nagyag. 
Grey  compact  quartz  is  locally  considered  to  be  the  best  host  for 
gold.  Galena  and  blende  with  white  sugary  quartz,  are,  on  the 
other  hand,  unfavourable  "  indicators."  Junctions  of  lines  of 
pyritous  impregnation  are  regarded  as  particularly  favourable 
spots  of  enrichment  here,  as  at  Nagyag.  The  complete  absence  of 
marked  relations  between  the  gold  tenor  of  the  quartz  veins  and 
the  enclosing  country  indicates  with  sufficient  clearness  that  the 
vein-filling  has  been  dependent  on  the  younger  Tertiary  volcanic 
activity.  The  high  values  obtained  in  the  upper  zones  of  the 
Troicza,  Tresztya,  and  Barbara  mines  have  not  persisted  into  the 
lower  levels. 

The  Kisalmas-Porkura  mines  lie  on  the  northern  boundary  of 
the  Csetras  mountains  and  some  7  miles  north  of  Nagyag.  The 
fundamental  rock  of  the  district  is  melaphyre.  The  veins  lie  in 
melaphyre  and  also  in  quartz-porphyry  (porphyrite).  The  stock- 
werk  of  the  Ludwig  mine  is  situated  within  a  zone  of  contact- 
breccia,  formed  at  the  junction  of  a  dacite  that  is  intrusive  through 
the  melaphyre.  The  breccia  is  50  to  100  feet  wide,  and  has  been 
followed  for  a  length  of  200  feet,  and  for  a  depth  of  nearly  500  feet. 
The  highly  decomposed  breccia  fragments  are  thoroughly  im- 
pregnated with  pyrite  and  are  cemented  by  calcite,  quartz,  and 
auriferous  pyrite.  The  dacite  fragments  in  the  breccia  carry, 
however,  but  little  pyrite.  It  is  notable  that,  in  these  ore- 
deposits,  free  gold  is  found  resting  on  the  predominant 
octahedral  planes  of  the  pyrite.  The  gold  thus  obtained  has 
a  fineness  of  853.  The  tenor  of  the  ore  varies  from  a  few 
pennyweights  to  3  ounces  per  ton,  with  an  average  of  perhaps 
an  ounce.  The  occurrence  of  amethystine  quartz  is  locally 
considered  to  indicate  the  presence  of  gold.  Semper  conjectures 
that  the  vein-filling  came  along  the  fissures  and  into  the  breccia 
from  a  hornblende-andesite  magma  lying,  at  depth. 

Boicza. — The  Boicza  mines,  lying  midway  between  Nagyag 
and  Brad,  date  back  to  Roman  times.  They  lie  on  the 
northern  slopes  of  the  Szvregyel  mountain,  2,237  feet  (682  m.) 
high,  which  forms  here  the  highest  point  of  the  mountain 
complex  of  Jura-Cretaceous  melaphyre  and  of  quartz-porphyry 
rocks.  The  oldest  levels  (Katherina  and  Barbara)  lie  on  the 
southern  slopes  of  this  hill,  whilst  further  north  are  the  Rudolf 
and  Josef  levels.  The  Klein  level  first  traverses  highly-weathered 
melaphyre  and  then  passes  into  a  soft  grey  kaolinised  rock 
termed  "dacit-tuff,"  which,  however,  is  really  a  weathered  quartz- 
porphyry  that  has  been  intruded  through  the  melaphyre.       The 


182  EUROPE. 

latter  is  much  altered,  and  in  the  neighbourhood  of  the  ore-fissures 
often  decomposes  spheroidally,  with  a  deposit  of  greyish  hornstone 
or  brick-red  chalcedony  between  the  spheroids.  In  contact  with  the 
vein  the  melaphyre  is  decomposed  to  a  soft  calcareous  kaolinic  mass. 
Two  systems  of  fissuring  are  evident.  Glauch  veins  of  33  to  66  feet 
in  thickness  occur  at  Boicza,  but  differ  from  those  of  Nagyag  in  the 
greater  size  of  the  brecciated  fragments  and  in  their  greater  regularity 
in  strike  and  dip,  and  further  by  the  absence  of  the  dark  colour  due 
to  impregnated  pyrite.  The  ore-bodies  follow  the  course  of  the 
glauch  veins,  especially  in  the  hanging- wall  country.  Many  also  lie 
in  the  breccia  itself.  The  width  of  the  veins  is  small,  and  seldom 
reaches  a  foot.  The  vein  matter  is  similar  to  that  of  Troicza  and 
Tresztya.  The  free  gold  has  a  fineness  of  600  to  700.  Nothing 
positive  may  be  said  concerning  the  distribution  of  the  richer  ore- 
bodies.  Great  thickness  of  vein  and  extensive  alteration  of  the 
country  are  here,  as  elsewhere  in  Transylvania,  indications  of 
enrichment.  Those  veins  that  accompany  glauch  lodes  may  generally 
be  distinguished  by  greater  productiveness.  Local  enrichments 
occur  at  the  junctions  and  intersections  of  veins  where  these  make 
an  acute  angle.  Higher  values  are  found  also  on  the  hanging- wall 
when  the  breccia  there  contains  no  melaphyre  fragments.  Further, 
a  quartzose  gangue,  especially  when  in  the  form  of  amethystine  or 
brick-red  chalcedonic  concretions  in  a  weathered  melaphyre, 
generally  indicates  high  values.  With  increase  in  depth,  the  gold 
tenor  is  gradually  diminished,  a  feature  due,  probably,  to  the  removal 
of  base  matter  and  gangue  in  the  upper  levels.  In  1895,  9,452 
ounces  (294  kg.)  gold  and  5,359  ounces  (166-7  kg.)  silver  were  pro- 
duced from  these  mines.     The  fineness  of  the  gold  was  668. 

The  most  important  mines  of  Transylvania  at  the  present  day 
lie  in  the  Western  Csetras  mountains,  which  are  formed  of  dacite 
hills,  the  product,  not  of  a  single-fissure  eruption  as  in  the  Eastern 
Csetras,  but  of  a  succession  of  eruptions.  The  region  is  charac- 
terised by  great  abundance  of  hypersthene-amphibole-andesite 
together  with  apparently  younger  eruptive  rocks.  Jurassic 
melaphyre  is  associated  with  the  Klippenkalk  (cliff-limestone), 
and  further  with  a  quartz-porphyry  a  little  to  the  south  of  Brad. 
It,  however,  carries  no  workable  deposits.  The  Tertiary  eruptive 
rocks  overlie  the  Carpathian  sandstone  (Cretaceous)  in  the  north, 
while  in  the  south  and  west  they  cover  Lower  Miocene  shales, 
sandstone  and  conglomerate. 

In  the  eastern  spurs  of  these  mountains  lie  the  few  rich  occur- 
rences of  Felso-Kajanel.  Here  the  dacites  have  broken  through  the 
Miocene  sediments  which  form  the  basement  rock  of  the  Kajanel 
mountains.     The   dacites   and   dacite-tuffs   are   developed    in   the 


HUNGARY.  183 

mountains  of  Goronaand  Manesiu.  They  are  in  their  turn  intruded 
by  hornblende-andesite.  The  auriferous  veins  lie  in  the  dacite 
and  dacite-tuffs.  They  also  pass  into  the  hornblende-andesite,  but 
there  soon  thin  out  into  barren  stringers.  The  two  most  important 
veins  are  the  "  Gold  "  and  "  Silver  "  veins.  Three  generations  of 
quartz  have  been  made  out.  The  oldest  formed  quartz  of  the 
Kajanel  mines  carries  free  gold,  pyrite,  marcasite,  chalcopyrite,  and 
silver  sulphides.  A  younger  quartz  carries  galena,  blende,  pyrite, 
chalcopyrite,  brownspar,  and  calcite  ;  a  still  younger,  brownspar, 
barytes,  and  gypsum,  with  gold,  silver,  fahlore,  chalcopyrite,  &c. 
Propylitisation  of  the  dacite  is  a  characteristic  feature,  and  is 
attended  by  considerable  richness  in  adjacent  veins.  The  kies- 
schnure  (pyritous  impregnations)  above-mentioned,  also  indicate  an 
enrichment  that  may  take  place  in  well-defined  shoots.  Despite 
several  such  rich  shoots  the  mines  have,  on  the  whole,  not  been 
profitable. 

Ruda, — In  the  western  end  of  the  Csetras  mountains,  between 
the  hills  of  Gyalu  Fetye,  2,300  feet  (701m.),  and  of  Hrenyak, 
2,460  feet  (750  m.),  are  the  Muszari  mines.  The  basement  rock  is 
melaphyre.  Hypersthene-bearing  dacite  and  hornblende-andesite 
are  traversed  by  various  levels  of  the  mines,  thus  affording 
considerable  scope  for  observation  of  propylitic  changes.  In 
the  east  of  the  field  the  veins  strike  from  north  to  north-west, 
but  in  the  southern  portion  they  intersect  so  irregularly  that 
they  appear  almost  to  radiate  from  a  centre.  The  thickness 
of  the  veins  is  generally  less  than  4  inches.  The  gangue 
minerals  resemble  those  found  elsewhere  in  Transylvania,  free 
gold  being  found  with  pyrite  and  showing  often  fine  distorted 
crystallized  plates  and  leaves,  with  masses  of  crystal  aggregates. 
The  more  characteristic  associates  of  the  gold  are  crystallized  black 
blende,  galena,  marcasite,  and  grey  or  green  chalcedonic  quartz. 
In  age  the  grey  chalcedonic  quartz  appears  to  be  the  oldest.  After 
it  were  deposited  pyrite,  free  gold,  galena;  and  blende,  then  chalco- 
pyrite, and  marcasite,  and  finally  a  second  deposition  of  free  gold. 
Calcite  and  dolomite  are  sometimes  younger  and  sometimes  older 
than  free  gold.  The  veins  in  the  andesite  are,  as  a  rule,  calcitic, 
and  those  in  the  dacite,  quartzose.  Local  enrichments  are  always 
expected  at  junctions  or  intersections  ;  indeed,  the  mines  of 
Muszari  largely  owe  their  productiveness  to  the  great  number  of 
such  gold-bearing  junctions.  In  the  year  1891  a  central  point  Avas 
reached  to  which  all  the  veins  in  the  vicinity  appeared  to  be 
converging.  Ore  from  this  rich  central  deposit  yielded  gold  to  the 
amount  of  30  to  even  100  ounces  per  metric  ton.  There  is  thus 
in  this  feature  considerable  analogy  with  the  far  richer  deposits 


184 


EUROPE. 


in  similar  rocks  of  the  Thames  goldfield  in  the  North  Island  of 
New  Zealand,  where  similar  intersections  ("  Shotover  "and"  Cale- 
donian ")  yielded  bonanzas  of  many  hundred  thousands  of  ounces 
gold.  At  Muszari  the  galena  itself  is  auriferous  in  bulk.  Other 
indications  of  the  proximity  of  bonanzas  are  :  extensive  altera- 
tion of  the  country  ;  a  medium  thickness  of  vein  ;  and  contact  with 
the  so-called  kiesschnure.  The  workings  have  reached  a  depth 
of  more  than  750  feet  without  perceptible  impoverishment  in  the 
tenor  of  the  ore. 

The  mining  districts  of  the  Barza  region,  to  the  east  of  Hrenyak, 
lie  in  the  valleys  of  Ruda,  Barza,  Valea  Mori,  and  Valea  Arszului, 
and  together  with  Muszari,  are  combined  to  form  the  property  of  the 
Harkort    Gold  Mining    Company,    better    known    as    the    Twelve 

Apostles  Mine,  in  1908  the 
richest  and  most  productive 
gold  mine  in  Europe. 

These  mines  were  un- 
doubtedly worked  by  the 
Romans,  and  numerous 
traces  of  their  extensive 
operations  are  still  extant 
in  the  form  of  levels  and 
shafts,  implements,  and  ma- 
chinery. Indeed,  Roman 
activity  was  widespread 
over  the  whole  of  the  Tran- 
sylvanian  Erzgebirge,  and 
3.  Quartz"  stringers  with  few  valleys  are  without 
traces  of  their  mining  works. 
From  the  Middle  Ages  until  quite  recently  the  Ruda  mines  have 
been  in  the  hands  of  noble  Hungarian  families.  In  1884,  they,  and 
eight  years  later,  the  other  mines  above-mentioned,  came  into  the 
possession  of  the  present  company  (Harkortsche  Bergwerk,  &c). 

The  general  geological  formations  represented  in  the  neigh- 
bourhood of  the  Twelve  Apostles  Mines  may,  for  comparison  with 
other  Transylvanian  occurrences,  be  briefly  summarised  in  the  table 
below  : — 


VA 

Fig.  82.    Glauch  Vein's,  Valea  Mori  (Bauer). 

1.  Dark  Glauch  vein  (oldest).      2.  Grey  Glauch  vein 
with  fragments  of  black  slate. 
free  gold  (youngest). 


Age. 

Eruptive  Rocks. 

Sedimentary  Rocks. 

Trias- Jura    

Cretaceous   

Miocene        

Recent 

Melaphyre       

Porphyrite      

Andesite 

Klippenkalk. 
Carpathian   Sandstone. 
Mediterranean   Beds. 
Diluvium. 
Alluvium. 

HUNGARY. 


185 


The  oldest  rocks  are  the  melaphyre-tuffs  and  lavas  of  the 
Lower  Trias.  These  are  largely  developed  in  the  lower  Ruda 
Valle}r.  They  were  depressed  below  the  level  of  the  sea  at  the 
close  of  the  Trias,  permitting  the  deposition  of  the  coral  reefs  of  the 
Klippenkalk  of  the  Jurassic  period.  This  formation  is  not  wide- 
spread in  the  immediate  neighbourhood  of  the  mines,  but  it  has  a 
considerable  development  along  the  main  water  parting  between 
the  Maros  and  the  White  Koros.      Then  followed  an  eruption  of 


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Fig.  83.     Geological  Sketch  Map  of   the  "Twelve  Apostles"  Mine,  Ruda, 

Transylvania  {Primics). 

1.  Jurassic  limestone.    2.  Melaphyre.    3.  Carpathian  Sandstone.    4.  Quartz-porphyry. 
5.  Mediterranean  (Miocene)  Beds.  6.   Andesitic  tuffs.         7.  Dacite. 

8.  Amohibole-andesite.  9.  Garnet- andesite.         10.  Hypersthenc-hornblende-andesite. 

porphyrite  (quartz-porphyry)  succeeded  by  the  deposition  in 
Cretaceous  times  of  the  Carpathian  sandstone.  Thereafter  a  great 
gap  in  time  intervenes  until  the  deposition  of  the  Mediterranean  Beds 
(Miocene).  The  lower  beds  of  this  stage  are  made  up  of  red  greyish 
clays,  with  and  without  pebble  beds;  the  middle  beds  are  conglomerate, 
grit,  and  sandstone,  and  contain  at  times  workable  coal  seams. 
Somewhat  remarkable  black  shales  occur  in  these  beds  in  the 
Valea  Mori,  and  are  believed  by  Semper  to  represent  mud  eruptions  ; 


186  EUROPE. 

Von  Palfy,  on  the  other  hand,  considers  them  to  be  of  entirely  normal 
sedimentary  origin. 

The  beds  of  the  Mediterranean  stage  were  intruded  and  covered 
by  great  andesitic  eruptions  that  produced  tuffs,  breccias,  and  lavas. 
The  last,  when  broadly  considered,  show  four  fairly  distinct  types  :■ — 

( 1 )  Pyroxene-amphibole-andesite . 

(2)  Amphibole-andesite. 

(3)  Dacite    (quartz-bearing    biotite-amphibole-andesite). 

(4)  Garnetiferous  dacite. 

According  to  Von  Palfy,  the  above  is  also  the  order  of  the 
eruption.  The  rocks  are  largely  altered  or  propylitised  (in  grun- 
steinartige  modifikation  umgeivandelte).  A  number  of  old  levels  on 
the  slopes  of  Barza  and  Koranda  mountains  are  in  propylitised 
hornblende-andesite,  with  which  also  are  associated  the  productive 
veins  in  the  deeper  workings. 

The  mines  of  Ruda  and  Barza  are  working  a  double  system  of 
veins,  the  members  of  which  have  an  average  thickness  of  15  inches 
to  3  feet.  The  more  important  are  the  Magdana,  Kornya,  Michaeli, 
and  Josephi  veins.  A  third  system  lies  further  west  than  the  fore- 
going. The  minerals  occurring  in  the  Valea  Mori,  Ruda,  and 
Barza  Mines  are  essentially  the  same  as  those  of  Muszari  already 
described.  In  the  Valea  Mori  the  country  of  the  Francisca  vein  is 
the  above-mentioned  black  shale  of  the  Mediterranean  stage.  It 
has  been  concluded  by  B.  Von  Inkey  that  the  vein  fissures  of  this 
region  are  a  direct  result  of  contraction  due  to  the  cooling  of  the 
eruptive  rocks.  With  this  view,  most  authorities  who  have 
visited  the  field  express  themselves  in  complete  accord. 

About  one  half  the  gold  yield  of  the  Twelve  Apostles  Mines 
comes  from  free  gold  of  an  average  fineness  of  700.  In  the  vein- 
filling  the  oldest  deposited  member  appears  to  be  solid  calcite  or 
quartz,  the  latter  being  often  chalcedonic.  Of  contemporaneous 
age  are  probably  the  associated  gold,  pyrite,  chalcopyrite,  galena, 
and  blende.  The  rhodochrosite  of  the  Valea  Mori  veins  comes  next 
in  age.  The  walls  of  the  drusy  cavities  between  the  older  minerals 
are  covered  with  crystals  of  quartz  and  calcite  on  which  the  later 
generation  of  gold,  pyrite,  chalcopyrite,  galena,  and  blende  is 
deposited.  The  youngest  vein-deposits  are  siderite,  barytes,  and 
gypsum.  The  chalcopyrite  that  accompanies  the  gold  pockets  is 
itself  often  very  highly  auriferous.  As  a  rule,  the  thin  veins  in  the 
rocks  of  the  crater  walls  of  the  ancient  Valea  Mori  volcano  are 
richer  than  the  larger  and  better-defined  veins  that  traverse  the 
andesite  of  Barza  and  Ruda.  The  ores  of  Valea  Mori  carry 
from  2  to  3|  ounces  (60  to  105  grams)  gold,  of  which  16  dAvts.  to  2 
ounces  (25  to  63  grams)  are  free  gold  ;   those  from  Ruda  only  carry 


HUNGARY. 


187 


from  13  to  21  ctwts.  (20  to  33  grams),  of  which  all  except  5  to  7| 
dwts.  (8  to  12  grams)  is  free  milling.  Considering  the  veins  broadly 
no  depreciation  in  value  can  be  made  out  with  increase  in  depth  ; 
on  the  contrary,  the  gold  production  tends  to  rise  from  year  to  year. 
The  level  of  the  richest  zone  is  about  1,150  to  1,230  feet  (350  to 
375  metres)  above  sea-level.  The  following  table  shows  the  product 
of  these  mines  from  1885  to  1904,  a  period  of  20  years. a 


Year. 

Metric  Tons 
Crushed. 

Kg.  Crude  Gold. 

Gram  Gold  per 
Ton. 

Costs  per  Ton  in 
Kroner.* 

1885 

5,855 

60164 

1027 

34-45 

1886 

6,362 

58-929 

9-27 

49-56 

1887 

13,360 

114-384 

8-56 

23-30 

1888 

17,898 

209-019 

11-67 

1764 

1889 

28,659 

467035 

16  06 

19-94 

1890 

44,403 

687-630 

15-49 

1790 

1891 

57,751 

770-490 

1334 

18-21 

1892 

54,373 

654326 

12  04 

1871 

1893 

53,686 

619-725 

11-53 

1814 

1894 

56,719 

530-758 

9-35 

1712 

1895 

53,236 

549-571 

10-32 

17  64 

1890 

57,824 

660567 

11-41 

16  44 

1897 

71,807 

833343 

11-59 

14-77 

1898 

68,193 

786-582 

11-51 

1517 

1899 

94,900 

877-143 

9-24 

12-89 

1900 

118,424 

1138-255 

9-61 

1103 

1901 

134,114 

1198019 

8-41 

10  82 

1902 

151,484 

1167-033 

7-70 

10-38 

1903 

157,803 

1219034 

7-72 

9  85 

1904 

163,358 

1412-464 

8-64 

1005 

*  An  Austrian  crown  is  worth  lOd. 

The  total  amount  of  crude  gold  produced  to  the  end  of  1904  was 
therefore  450,243  ounces  (14,004-471  kg.)  derived  from  1,410,209 
tons  ore,  or  an  average  return  of  6-3  dwts.  (9-9  grams)  per  metric 
ton.  The  fineness  of  the  bullion  varies  from  600  to  700.  The 
total  value  of  the  output  of  these  mines  in  the  stated  time  is 
somewhat  less  than  one  and  a  quarter  millions  sterling. 

Karacs-Czebe. — The  Karacs-Czebe  district,  a  few  miles 
south  of  Korosbanya  on  the  white  Koros  River,  contains 
the  most  westerly  mines  of  the  Transylvanian  auriferous 
region.  The  oldest  rock  of  the  area  is  melaphyre  or 
augite-porphyry,  which  occurs  both  as  flows  and  as  tuffs 
distinguishable  from  each  other  only  with  the  greatest  difficulty. 
These  are  overlain,  as  in  the  Barza  region,  first  by  the  Jura- 
Triassic  Klippenkalk,  then  by  the  Cretaceous  Carpathian  sand- 
stone, and  again  by  Miocene  reddish  clays    and  conglomerates  on 


a  Bauer,  Berg-  und  Hiitt.  Jahrs.  der  k.k.  montan.  Hochsch.  zu  Leoben  und  Pribram, 
LIII,  1905,  p.  85. 


188  EUROPE. 

which  workable  seams  of  brown  coal  lie.  On  these  sedimentary 
rocks  andesite  lava  streams  were  poured  forth  during  the  Mediter- 
ranean and  Sarmatian  (Miocene)  stages,  and  were  propylitised  by 
subsequent  solfataric  action,  during  which  operation  ore-deposition 
took  place.  The  minerals  of  the  Karacs-Czebe  mines  are  native  gold 
(750  to  795  fine),  sylvanite,  nagyagite,  pyrite,  galena,  blende, 
rhodochrosite,  alabandite,  and  pyrolusite,  all  in  a  gangue  of  quartz 
and  calcite.  The  tellurides  are  especially  characteristic  of  the  Czebe 
stock.  The  Peter-Paul  lodes  of  Karacs  have  a  tenor  of  about  9 
dwts.  gold  per  ton,  and  the  Peter-Paul  stock  of  Czebe  from  6 
dwts.  to  18  dwts.  per  ton.  The  general  result  of  the  actual  working 
of  these  deposits  for  a  year  and  a  half  showed  an  average  recovery 
of  5  dwts.  (8  grams)  per  ton,  which  is  very  probably  a  closer  approxi- 
mation to  their  true  value  than  numerous  high  assays  that  have  been 
published  from  time  to  time.  Von  Pappa  estimates  that  in  the 
2,000  years  of  working  at  Karacs-Czebe  at  least  7,500  kg.  (241,125 
ounces)  gold  has  been  extracted  from  the  veins  and  a  further  5,000 
kg.  (167,500  ounces)  from  the  placer  deposits  of  the  streams  that  run 
from  the  veins  towards  the  White  Koros  at  Korosbanya.  These 
last  are  worked  even  at  the  present  day,  and  rough  trials  made  by 
Von  Papp  showed  tenors  over  limited  areas  of  from  1 J  to  H  dwts.  (2 
to  2-5  grams)  per  metric  ton.b 

Placer  Deposits. — The  auriferous  placer  deposits  of  Austria- 
Hungary  have  been  described  in  detail  by  Grimm.c  They  have 
been  found  more  particularly  on  the  Aranyos  (golden  river)  in  Tran- 
sylvania, from  its  source  in  the  Bihar  mountains  to  its  junction 
with  the  Maros.  The  Aranyos  lies  on  the  northern  boundary  of 
Transylvanian  auriferous  region,  whence  its  gold  has  certainly 
been  derived.  The  Warme  Czamos  flowing  to  the  north-east  from 
the  Bihar  mountains  also  carries  appreciable  quantities  of  gold,  as, 
indeed,  do  most  of  the  streams  cutting  through  the  auriferous 
area  (e.g.,  the  Feher  (white)  Koros  at  Czebe,  and  the  Maros  at 
Magyar-Csesztye).  Further  south,  across  the  Maros,  the  streams 
flowing  from  the  Pojana  Ruska  and  from  the  Golubinje  mountains, 

a  Von  Papp,  Zeit.  fur  prakt.  Geol.,  XIV,  1906,  p.  305. 

"  The  literature  of  the  Transylvanian  ore-deposits  is  extensive.  The  following  list 
perhaps  comprises  the  more  important  papers  :  Richthofen,  Jahrb.  der  k.k.  geol.  Reich. 
zu  Wien.  1860,  pp.  153-277  ;  Von  Cotta  and  Von  Fellenberg,  "  Ueber  Erzlagerstatten 
Ungarns  und  Siebenbiirgens,"  Gangstudien,  IV,  pp.  65,  156  ;  Von  Hauer  und  Stache, 
"  Geologie  Siebenbiirgens,"  Vienna,  1863;  Posepny,  Jahrb.  der  k.k.  geol.  Reich.,  1868, 
I.  p.  53  ;  Id.,  loc.  cit.,  1868,  II,  p.  7  ;  Doelter,  loc.  cit.,  1874,  I,  p.  7  ;  Id.,  Tschermak's 
Mittheil,  1874,  p.  13 ;  Id.,  loc.  cit.,  1880,  p.  1  ;  Thilo,  Berg-  und  Hiitten  Zeitung,  1889, 
pp.  125,  133 ;  Weisz,  Jahrb.  der  kgl.  ungar.  geol.  Landesanst.,  IX,  Pt.  6,  p.  105 ; 
Semper,"  Beitrage  zur  kenntniss  der  Goldlagerstatten  des  Siebenbiirgischen  Erzgebirges," 
Abhand.  kon.  Preuss.  geol.  Land.,  XXXIII,  1900,  Berlin,  p.  219 ;  Bauer,  Berg-  und 
Hiitt.  Jahrb    der  k.k.  montan.   Ho^hsch.  zu  Leoben  und  Przibram,  LIII,  1905,  p.  85. 

c  Oesterr.  Zeit.  fur  Bergwesen,  II,  1854,  pp.  91,  et.  seq.  ;    see  also  Horvath,   Montan 
Zeitung,  1907,  translated  Man.  Jour.,  Sep.  7,  1907. 


HUNGARY. 


189 


and  indeed  those  of  the  Banat  mountains  generally,  all  carry  a  little 
gold.  Small  dredges  have  been  operated  during  1 907  on  the  Aranyos, 
but,  being  of  faulty  construction  and  design,  have  not  proved  satis- 
factory." 

Old  gold  washings  are  known  in  the  valley  of  the  Bistritza  in 
Bukowina  in  Eastern  Hungary.  These  lie  between  Jakobeni  and 
Watro-Derna.  The  Moldava  in  Bukowina  also  carries  traces 
of  gold,  derived,  as  in  the  case  of  the  former  river,  from  andesitic 
auriferous  occurrences  similar  to  those  of  Nagybanya.  According 
to  Von  Gernet b  two  hundred  men  earn  from  2s.  to  3s.  per  day  per 
man  by  working  the  surface  gravels  of  the  beaches  of  the  Drave 
(Drau),  especially  between  Lakany  and  Visvar.c 

The  gold  production  of  Hungary  has  increased  largely  during  the 
last  three  decades  as  is  shown  by  the  yield  of  the  four  selected  years 
below  : — d 


Kroner. 

Sterling. 

1867 
1882 
1892 
1902 

4,935,760 

4,796,746 

6,268,874 

11,150,296 

£205,656 
199,864 
261,203 
464,595 

Of  the  foregoing  yield  of  1902  about  30  per  cent,  was  produced 
by  the  Twelve  Apostles  mines. 

The  recent  available  gold  returns  of  Hungary  are  as  follows  : — 


Washed  Gravel  and  Veinstone. 

Also  produced  at  Metallurgical 

Works. 

Vein  Gold. 

\ear. 

Metric  Tons. 

Value. 

Fine  Gold. 
Kg. 

Value. 

Kroner. 

Sterling. 

Sterling. 

1900 
1901 
1902 
1903 
1904 
1905 
1906 

6,246 
6,859 
5,655 
5,483 
5,622 
6,457 
6,597 

713,800 
973,600 
892,600 
955,600 
912,800 
1,002,000 
1,006,006 

£29,742 
40,566 
36,358 
39,816 
38,033 
41,715 
41,882 

3,267 

3,293 
3,400 
3,376 
3,669 
3,665 
3,738 

£445,945 
449,494 
464,100 
460,824 
500,818 
500,272 
510,349 

a  Horvath,  loc.  cit.  sup. 
b  Adv.  Sheets  Inst.  Min.  Met.,  1908. 

c  See  also  St.  Rainer,  "  Die  Gold-baggerei  in  Europa,"  Oesterr.  Zeit.  fur  Berg-  und 
Hiitt.,  Ap.  27,  1907. 

^  Bauer,  loc.  cit.  sup. 


190  EUROPE. 


GERMANY. 


The  Rhine. — Gold  washing,  especially  along  the  banks  of  the 
Rhine,  has  been  practised  in  Germany  from  the  earliest  times. 
Gold-quartz  veins  have  also  been  worked  during  many  centuries. 
The  gold  washings  along  the  Rhine  between  Basle  and  Mayence  were, 
as  early  as  667  a.d.,  the  subject  of  a  grant  by  the  ruler  of  Alsace  to  a 
monastery.  The  industry  is  now,  however,  conducted  on  a  very  small 
scale,  and  the  former  working  of  gold  is,  indeed,  in  many  places  quite 
forgotten.  At  Waldshut,  above  Basle,  gold  is  known  to  occur  in 
minute  quantities,  but  the  principal  deposits  of  the  Rhine  lie  along 
the  stretch  of  160  miles  between  Basle  and  Mayence.  Descending 
the  stream,  deposits  are  even  now  from  time  to  time  washed  at 
Istein,  Kleinkems,  Rheinweiler,  and  Niffer.  Richer  gravels,  but 
of  extremely  irregular  tenor,  occur  at  Nambsheim,  Geiswasser,  and 
Altbreisach  ;  the  majority  of  the  workings  are,  however,  still  further 
down  the  river,  below  Rheinau,  on  the  Alsace  side,  and  Witten- 
weyer,  about  65  miles  below  Basle.  The  best  reach  is  from  above 
Kehl  (opposite  Strasburg)  to  Dachslander,  near  Karlsruhe,  and  more 
particularly  that  portion  of  it  at  Helmlingen,  some  14  miles  below 
Kehl.  From  Speyer  to  Mayence — the  remainder  of  the  auriferous 
reach — the  deposits  are  unimportant.  On  the  whole,  the  deposits 
of  the  right  bank  (Baden)  are  richer  than  those  of  the  left  (Alsace). 

The  gold  occurs  as  tiny  flakes  in  the  coarser  gravel,  being  dis- 
tributed through  it  in  association  with  the  larger  pebbles,  that 
make  up  40  to  50  per  cent,  of  the  auriferous  sands.  The  auriferous 
stratum  lies  mostly  on  the  surface  of  the  beaches,  and  is  seldom 
more  than  6  to  10  inches  deep,  sometimes,  however,  being  covered 
by  a  layer  of  fine  sand.  The  tenor  of  the  gravel  is  1  •  7  to  12  grains 
per  cubic  yard  ( -0146  to  1-011  gram,  per  cubic  metre).  The  lowest 
tenor  nowadays  considered  profitable  is  at  least  2-75  grains  per 
cubic  yard.  This  tenor  is  not  now  found  in  the  present  bed  of 
the  Rhine,  but  in  the  gravels  of  the  valley,  some  6  to  8  miles 
distant  from  the  stream  ;  also  a  like  tenor  may  be  obtained  in  the 
gravels  of  the  111,  near  Geispolsheim,  that  are  covered  by  fine  sand 
of  no  value.  According  to  Daubree,  the  quartz-pebbles  of  the 
Rhine  occasionally  carry  gold,  one  such  found  in  the  111  near 
Strasburg,  being  thickly  impregnated. 

The  gold  of  the  Rhine  is  934  fine,  with  66  silver.  Platinum  to 
the  extent  of  -069  per  cent,  has  also  been  found.  The  heavy  sands 
contain  10  to  14  per  cent,  titanite,  with  rose  quartz  and  a  little 
zircon.  Of  the  Alsace  yield  there  is  no  definite  information,  but 
records  were  kept  of  the  production  of  the  Grand-Duchy  of  Baden 
until  1874,  when  the  yield  became  too  trifling  to  record.     From 


GERMANY.  191 

1748  to  1799  about  1,850  ounces  (57-6  kilos)  and  from  1800  to  1874, 
9,810  ounces  (305-61  kilos)  were  recovered.  Von  Cotta  states  that 
400  washers  were  at  work  in  Baden  in  1859.  In  the  Pfalz  Palatinate 
from  1825  to  1862  some  1.573  ounces  (49  kilos)  were  obtained/' 
The  Rhine  washings  are  now  completely  abandoned,  except  for  a 
little  occasional  amateur  washing.  It  is  said  that,  towards  the  close 
of  the  eighteenth  century,  the  lower  Rhine  in  the  neighbourhood 
of  Wesel  (Dusseldorf)  produced  gold.6 

Small  grains  of  gold  are  met  with  from  the  Lower  Devonian  of 
Goldbach,  west  of  Bernkastel  in  the  bed  of  the  Andel,  which  falls 
from  the  south  into  the  Moselle  (Trier  or  Treves  district).  These  are 
especially  numerous  after  floods,  and  possibly  point  to  the  occur- 
rence in  the  immediate  neighbourhood  of  gold-quartz  veins,  similar 
to  those  found  across  the  French  frontier  in  the  Ardennes.  In  the 
Aachen  district  also,  east  and  south  of  Malmedy,near  Buttgenbach,  at 
Montenau,  Born,  and  Recht,  and  from  Ligneuville  as  far  as  Stavelot 
(Belgium),  are  old  gold-washers'  pits.  They  follow  a  bed  of  quartzite 
and  conglomerate,  which  lies  for  about  35  miles  along  the  contact 
of  the  Lower  Devonian  and  Cambrian,  and  which  appears  to  be  the 
matrix  of  the  gold.  Prospecting  along  this  line  has,  however,  met 
with  no  success.0 

Other  Rivers. — Gold  in  valley  alluvials  occurs  along  the  West- 
phalian  mountains  in  the  Brilon  circle,  Arnsberg  district ;  in  the 
Diemel  from  Westheim  above  Stradtberge  to  its  junction  with  the 
Rehne  ;  and  in  the  Hoppeke  from  its  junction  with  the  Diemel  to 
the  boundary  of  the  principality  of  Waldeck  ;  in  the  Orke  at  Ron- 
ningshausen  ;  and  in  the  Aar  below  Titmaringhausen.  Old  mine 
workings  in  this  region  carry  pyrites,  and  in  the  adjacent  principality 
of  Waldeck,  at  Goldhausen  in  the  Eisenberg,  a  gold-bearing  copper 
pyrite  deposit  occurs  in  sandy  slates  and  limestones.  These 
deposits  in  the  fifteenth,  and  more  particularly  about. the  middle 
of  the  sixteenth  century,  yielded  gold.  In  the  eighteenth  century 
explorations  were  made,  and  were  from  time  to  time  continued, 
always  unsuccessfully,  as  between  1850-1860,  into  the  nineteenth 
century.  The  sands  of  the  Eder  are  auriferous  from  Frankenberg 
(Cassel)  through  Waldeck  and  the  Fritzlar  district,  to  its  junction 
with  the  Fulda  at  Guntershausen,  and  although  extended  trials  have 
failed,  yet  gold  in  small  quantities  has  been  washed  in  recent  times 
in  the  neighbourhood  of  Fritzlar,  Altenberg,  and  Felsberg. 

a  Neumann,  "  Die  Goldwascherei  am  Rliein,"  Zeit.  Berg.  Hiitt.  und  Sal.  Wesen,  LI, 
1903,  pp.  377-420. 

b  Bruhns,  "  Nutzbaren  Mineralien  im  deutschen  Reiche,"  Berlin,  1906,  p.  559. 
c  Berg-  mid  Hiitten  Zeitung,  1899,  p.  265. 


192  EUROPE. 

Thuringer  Wald. — Important  gold  mines  were  worked  in 
ancient  times  at  Goldisthal,  Reichmannsdorf,  and  Steinheide,  north 
of  Coburg  in  the  south-eastern  portion  of  the  Thuringer  Wald. 
They  were  flourishing  in  1209,  were  abandoned  by  1430,  and  re- 
opened in  1533.  The  Giite-Gottes  mine  at  Petersburg  from  1576 
to  1580  yielded  about  75lbs.  fine  gold.  Abandoned  in  1635  on 
account  of  the  Thirty  Years'  War,  it  was  re-opened  by  Duke  Albrecht 
in  1692.  In  1700  there  were  gold  washings  on  the  Werra  and  the 
Ilz  near  Schwarzen-brunn  and  Schalkau  (Meiningen),  but  these  have 
long  been  abandoned.  The  gold-quartz  veins  formerly  worked  lay 
in  the  Cambrian  quartzites  and  carried  pyrite,  mispickel,  and 
haematite.  The  gold  occurs  as  grains  and  flakes.  The  neighbour- 
ing Schwarza  from  its  source  to  its  mouth  yielded  alluvial  gold. 
In  1530  there  were  no  less  than  20  gold  washings  in  the  principality 
of  Schwarzburg-Rudolstadt,  and  trials  made  in  1859  proved  the 
continued  existence  of  gold.  In  Schwarzburg  gold  has  been  washed 
in  modern  times.  At  Reichmannsdorf  gold-quartz  veins  occur  in  the 
Cambrian.  Below  Glasbach  veins  in  granite  yield  gold  associated 
with  haematite  and  titanite.  There  is  alluvial  gold  in  the  Lauscha, 
Goritz,  Goldbach,  and  Rogitz,  and  at  Steinheide  and  Selsendorf, 
and  in  the  neighbourhood  ;  also  in  the  Grand  Duchy  of  Sachsen- 
Weimar  at  Weida  and  Kreuzberg,  and  at  Jena  on  the  Saal.  There 
is  still  preserved  in  the  church  of  Jena  a  nugget  of  gold,  which  was 
found  in  the  neighbouring  washings  in  1587. 

Harz. — In  the  Harz  mountains  gold  occurs  in  the  pyritous 
ores  of  the  Rammelsberg  to  the  extent  of  7  J  to  15  grains  per  metric 
ton.  In  1894  the  Rammelsberg  smelting  works  thus  produced 
2,450  ounces  (76-3  kg.)  gold  worth  £10,682.  Native  gold  has  also 
been  observed  at  Tilkerode  in  plates,  leaves,  and  small  crystals 
associated  with  clausthalite,  Pb  Se,  and  lehrbachite,  (Pb  Hg2)  Se,  in 
a  gangue  of  calcite." 

Bavaria. — In  the  Fichtelgebirge  gold  occurs  in  several  localities, 
either  in  veins  or  in  gravels.  The  Goldkronach  mine,  according  to 
Agricola,  yielded  weekly  a  profit  of  1,500  Rhenish  gulden.  Mining 
at  Goldkronach  dates  back  at  least  to  the  fourteenth  century.  After 
a  long  abandonment,  operations  were  actively  resumed  in  1800 
under  the  direction  of  the  famous  traveller,  Von  Humboldt,  but 
ceased  again  in  1861.  The  veins  occur  mainly  in  light  green  Cam- 
brian slates.  The  gangue  is  quartz,  spathic  iron,  and  calcite,  with 
occasional  barytes.  The  minerals  in  the  matrix  are  antimonite, 
auriferous  and  argentiferous  pyrite,  and  mispickel  with  occasional 
galena,  blende,  and  free  gold.& 

a  Pogg.  Ann.,  Ill,  1825,  p.  297. 

b  Schmidt,  Zeit.  fur  Berg.-Hiitt-u.  Sal.  Wesen,  LV,  1907,  Abh.  p.  449. 


GERMANY.  193 

These  veins  yield  the  alluvial  deposits  that  lie  in  the  Zoppaten- 
bach.  Auriferous  pyrite  has  been  worked  at  Goldberg,  near  Reich- 
mannsdorf. 

In  the  eastern  Bavarian  mountains  (Bohmer  Wald)  at  Neu- 
albenreuth,  and  at  Bodenmais,  are  gold  occurrences.  In  Upper 
Bavaria,  the  Iser,  Inn,  Ammer,  Salzach,  Alz,  and  Donau  rivers,  all 
carry  gold. 

Saxony. — Many  localities  are  known  on  the  northern  flanks 
of  the  Erzgebirge  in  which  gold  was  formerly  washed.  The  principal 
auriferous  stream  is  the  Goltzsch,  particularly  at  Falkenstein, 
Ellefeld,  Miihlgrun,  Auerbach,  Rodewisch,  &c.  The  oldest  washing 
appears  to  have  been  that  of  Mylau  (1564  a.d.).  The  rocks  of 
Johanngeorgenstadt  and  Eibenstock  on  the  Bohemian  frontier 
contain  auriferous  galena  veins.  Numerous  Saxon  streams 
(Striegis,  Schwarzwasser,  &c.)  carry  gold,  but  all  in  exceedingly 
small  quantities. 

Silesia. — Of  much  greater  importance  are  those  Silesian  alluvial 
occurrences  that  were  most  profitably  worked  during  the  twelfth  and 
thirteenth  centuries  ;  they  lie  especially  on  the  northern  side  of  the 
Reisengebirge  in  the  districts  of  Liegnitz,  Goldberg-Haynau,  and 
Lowenberg.  These  ancient  workings  were  extensive,  and  spread 
not  only  over  the  valley  gravels,  but  also  into  the  older  post- 
Pliocene  terraces.  The  principal  workings  appear  to  have  been  at 
Plagwitz,  Petersdorf,  Lowenberg,  Goldberg,  Wahlstatt,  Strachwitz, 
and  Liegnitz. 

Gold  occurs  at  the  Reicher  Trost  mines,  Reichenstein,  in  arsenical 
sulphides  (lollingite,  Fe  As2,  and  leucopyrite,  Fe2  As3)  together  with 
auriferous  galena,  blende,  chalcopyrite,  and  pyrite.  These  ancient 
mines  were  re-opened  for  arsenic  at  the  beginning  of  the  nineteenth 
century,  but  their  gold  content  was  neglected  until  1895,  when 
the  employment  of  the  chlorination  process  permitted  of  its  extrac- 
tion. The  ore-deposits  lie  in  dolomitic  rocks  closely  associated 
with  mica-schists.  The  deposit  is  30  to  130  feet  thick,  and  is 
1,300  yards  along  the  strike.  In  1903,  3,530  metric  tons  of  ore 
were  raised  from  the  Reicher  Trost  mine,  worth  about  £14,120 
(282,400  m.).  From  1895  to  1906  about  1,446  ounces  (45  kg.)  995 
fine  have  been  obtained.  A  small  part  of  the  gold  appears  to  be 
amalgamable,  but  the  greater  part  is  not  free.  The  general  tenor 
of  the  arsenical  ore  varies  from  2J  dwts.  to  21  dwts.  per  ton.a 

Gold  also  occurs  in  the  mispickel  ores  of  Rotenzechau,  near 
Schmiedeberg  (Hirschberg).      These  lie   in    a   talc-schist    band   in 

a  Weinecke,  Zeit.  fur  prakt.  Geol.,  Sep.,  1907,  XV,  p.  274 ;      Sachs,  "  Die  Boden- 
schatze  Scklesiens,"  Leipzig,  1906. 

N 


194 


EUROPE. 


mica-schists  near  a  granite  contact.  The  gold  tenor  is  3  dwts.  per 
metric  ton  (00048  per  cent.).a  Near  Kauffung  (Altenberg)  in  the 
Katzbach  mountains,  auriferous  pyrites  occurs  impregnating  an 
olivine-kersantite  intrusion.6  Neither  of  the  two  last  occurrences 
are  now  being  worked.  Ancient  alluvial  gravels  have  also  been 
washed  near  Lowenberg.  Their  gold  content  is  believed  to  be 
derived  from  quartz  lenses  in  a  pyritous  graphitic  schist.0 

The  following  table  shows  the  available  returns  of  the  produc- 
tion of  gold  and  silver  within  the  German  Empire.  Separate 
returns  for  gold  are  not  available.  The  probable  percentage  of  gold 
value  in  the  following  returns  is  from  10  to  15,  the  annual  gold  yield 
of  the  Empire  being  apparently  about  100  kg.  (3,215  ounces).^ 


Metric  Tons. 

Value. 
Marks. 

Value. 

•  Sterling. 

1900 

12,593 

2,059,000 

£102,950 

1901 

11,577 

1,551,000 

77,550 

1902 

11,724 

1,389,000 

69,450 

1903 

11,467 

1,245,000 

62,250 

1904 

10.405 

1,206,000 

60,300 

1905 

10,286 

1,194,000 

59,700 

1906 

8,066 

1,206,000 

60,300 

From  the  Kingdom  of  Prussia  during  the  same  period  gold  and 
silver  to  the  following  values  were  obtained  : — e 


Tons. 

Value. 

Value. 

V 

Marks. 

Sterling. 

1900 

1 

30,664 

£1,503 

1901 

6 

39,579 

1,940 

1902 

18 

183,441 

8,992 

1903 

13 

80,624 

3,952 

1904 

8 

71,425 

3,501 

1905 

4 

10,828 

530 

1906 

239 

49,480 

2,474 

a  Kosmann,  Berg-  und  Hiitten  Zeitung,  1891,  p.  329. 

"  Bruhns,  loc.  cit.  sup.,  p.  581. 

c  Eosenberg-Lipinsky,  Zeit.  fiir  prakt.  Geo!.,  1897,  p.  156. 

™  Vierteljakrshefte  zur  Statistik  des  deutschen  Beicks,  Heft  IV,  1901-1907,  Berlin. 

"-  Zeit.  Berg.  Hiitt.  Sal.  Wesen,  XLIX-LIV,  1901-1907. 


195 


NORWAY. 

The  first  recorded  discovery  of  gold  in  Norway  took  place 
during  the  reign  of  Christian  IV.  (1588-1642)  in  the  rich  silver 
veins  of  Kongsberg,  where  State  silver  mines  are  being  worked  to 
the  present  day.a  In  1705  gold  was  found  in  copper-ore  at  the 
Aardal  mines  on  the  Sogne  Fjord.  In  1 788  several  thousand  grammes 
gold  were  extracted  from  the  veins  of  the  Eidsvold  mines,  45  miles 
north  of  Christiania.  Numerous  pyritous  veins  in  Norway  contain 
small  quantities  of  gold,  as  also  do  the  galena  and  blende  mines  in 
Hatlefjelddalen.  The  silver  from  the  Svenningdalen  mines  often 
contains  one  per  cent.  gold. 

The  only  important  auriferous  occurrences  in  Norway  are  those 
of  Bommel  Island,  midway  between  Bergen  and  Stavanger./; 
The  gold  veins  are  restricted  to  an  area  of  a  half-mile  square  on 
the  north-eastern  portion  of  the  southern  half  of  the  island.  The 
outcrops  were  discovered  in  1883,  and  from  their  great  richness 
attracted  a  considerable  amount  of  attention.  Their  tenor,  however, 
decreased  with  depth,  and  only  one  company  (the  Oscar,  afterwards 
the  Bremnaes)  continued  work.  The  rock  of  the  southern  portion  of 
Bommel  Island  is  a  fine  crystalline  greenish  schist  in  which  are  con- 
tained large  masses  of  dioritic  rock  (saussurite-gabbro  of  Dahll), 
and  of  a  quartz-porphyry  that  may  pass  into  an  epidote-granite. 
This  complex  is  traversed  by  altered  diabasic  dykes  with  which 
the  auriferous  quartz  veins  are  closely  connected.  The  gold- 
quartz  veins  occur  principally  in  the  quartz-porphyry.  The  veins 
are  numerous.  Their  quartz  is  white  and  sugary,  and  contains 
pyrite,  chalcopyrite,  galena,  and  tetradymite,  with  occasional  blende. 
The  free  gold  is  generally  associated  with  pockets  of  calcite.  When 
this  is  so,  the  ore  may  reach  a  tenor  of  7  to  20  ounces  gold  per  ton. 
Occasionally  the  walls  of  the  lodes,  for  a  distance  of  6  to  12 
inches  from  the  vein,  are  highly  mineralised,  and  may  contain  several 
pennyweights  gold  per  ton.  The  width  and  value  of  the  veins  are 
extremely  variable  factors,  and  the  former  may  range  from  a  few 
inches  to  6  feet.  A  considerable  amount  of  work  has  been  done  on 
some  of  the  veins,  a  shaft  on  the  Oscar  Lode  reaching  a  depth  of 
550  feet.  The  average  tenor  in  1896  was  about  7|  dwts.  per  ton, 
and  from  1884  to  that  year  about  30,000  tons  ore  had  been  crushed, 
and  about  £30,000  gold  obtained. 

Other  auriferous  areas  occur  on  the  mainland,  ten  miles  from 
the  Bommel  veins.     The  country  in  these  areas  is  granite  intruded 

aDaw,  Trans.  Inst.  Man.  Met,,  V,  1896-1897,  p.  212. 

6  Reusch,  Neues  Jalirb.  fur  Min.,  1887,  Beil.  Bd.,  V,  p.  61. 


196 


EUROPE. 


by  diabasic  dykes  entirely  similar  to  those  of  Bommel  Island.  The 
gold-quartz  veins  are  small  and  low-grade.  Thirty-five  miles  further 
north,  in  the  parish  of  Olve,  Hardanger  Fjord,  there  occurs  a  net- 
work of  small  gold-quartz  veins  in  green  crystalline,  chloritic, 
hornblendic,  and  talcose  schists.  The  gold  occurs  not  only  in  the 
veins,  but  disseminated  throughout  the  schists.  Early  trials  showed 
that  the  gold  at  the  outcrop  was  very  largely  due  to  surface  enrich- 
ment, and  that  at  shallow  depths  the  general  tenor  was  only  1  dwt. 
per  ton. 

Gold-quartz  veins  are  known  on  Talg  Island,  near  Stavanger, 
and  also  in  Thelemark,  but  neither  have  been  extensively  worked. 
The  Svartdal  tourmaline-bearing  lodes  in  the  Thelemark  region, 
in  which  copper  ores  carry  appreciable  quantities  of  gold,  have  been 
generally  described  as  occurring  in  granite.  Vogt  a  has,  however, 
shown  that  the  country  is  really  a  quartz-mica-diorite,  thus  adding 
another  example  to  the  type  of  veins  in  quartz-mica-diorite  to  be 
considered  later  from  Eastern  North  America  and  Eastern  Australia. 

Many  Norwegian  rivers  contain  gold  in  small  quantities.  The 
richest  are  those  which  have  their  sources  in  the  far-north  district 
of  Karasjok,  Finmark,  where  there  are  numerous  quartz  veins, 
probably  the  source  of  the  gold.  The  rivers  usually  worked  are 
the  Altan,  Tana,  Jesjok,  and  Anarjok.  The  deposits  are  not  rich, 
and  extensive  work  is  hindered  by  the  climate,  which  permits  of 
only  four  to  five  months  work  in  the  year,  since  the  rivers  are  180 
miles  within  the  Arctic  Circle,  and  are,  with  a  possible  exception 
from  the  Upper  Koyukkuk  in  Northern  Alaska,  the  most  northerly 
gold  occurrences  recorded.  It  is  reported  that  by  panning  a  man 
may  collect  1  to  1|  dwts.  daily.  The  gold  is  rough,  and  is  about 
930  fine.  A  little  alluvial  gold  has  also  been  reported  from  the 
Topdal  and  Torrisdal  rivers,  near  Christiansand,  South  Norway.'' 

The  gold  production  of  Norway  from  the  most  recent  returns 
available  are  : — 


Kg.  Fine  Gold. 

Value. 
Kron. 

Value. 
Sterling. 

1900 

4  4 

9,000 

£500 

1901 

5  0 

10,000 

655 

1902 

520 

137,000 

7,611 

1903 

110 

31,000 

1,722 

1904 

1905 

«Zeit.  fur  prakt.  Geo!.,  1895,  p.  149. 
h  Min.  Journ.,  May  16,  1908. 


197 


SWEDEN. 

Nearly  all  the  gold  produced  in  Sweden  comes  from  the  treat- 
ment by  the  Munketell  process  of  the  residual  products  of  the  silver- 
copper  ores  of  the  famous  Falun  mine,  situated  in  the  province  of 
Kopparberg,  north-west  of  Stockholm.  This  mine  has  been  worked 
continuously  for  many  hundred  years.  According  to  Tornebohm  n 
the  country  is  mainly  a  fine  grained  biotite-gneiss  with  very  little 
mica.  Associated  with  the  biotite-gneiss  are  mica-  and  hornblende- 
schists,  quartzites,  limestones,  and  garnetiferous  rocks.  The  foot- 
wall  of  the  deposit  is  a  grey  micaceous  quartzite  intercalated  in 
gneiss,  while  the  great  mass  of  the  deposit  is  itself  a  quartzite 
thoroughly  impregnated  with  sulphides.  The  ordinary  copper-ore 
contains  perhaps  1  to  3^  dwts.  gold  per  ton.  In  1881  a  boy  dis- 
covered free  gold  in  white  quartz  veinlets  that  traverse  the  harder 
sulphide  ore.  Free  gold  in  these  is  always  associated  with  seleni- 
ferous  galena  and  bismuthinite.  Tenors  of  3  to  10  ounces  gold  per 
ton  were  not  uncommon,  but  the  average  free  gold-ore  contains 
only  from  6  dwts.  to  an  ounce  per  ton.  The  richest  gold-quartz  is 
found  near  intrusive  diorites.^ 

A  little  gold  has  also  been  obtained  from  the  silver-lead  mines 
of  Kafveltberg  ;  from  quartz-veins  in  the  gneissose  granite  of 
Adelfors  in  Smaland,  where  the  gold  is  associated  with  pyrite,  galena, 
&c.  ;  and  as  rare  occurrences  in  the  Svappavara  mine,  Tornea  dis- 
trict, and  in  the  Bastnas  mine  in  Westmanland.c  Towards  the 
end  of  1907  the  discovery  of  a  rich  gold-copper  vein  was  reported 
from  the  Nantanen  mines,  Bjorquirgts  goldfield,  Norboten 
province,  in  the  extreme  north  of  Sweden.^ 

The  total  gold  yield  of  Sweden  has  been  estimated  as  follows: — e 


Period. 

Ounces. 

1400—1493 
1506—1600 
1601—1700 
1701—1800 
1801—1900 

1,980,130 
3,055,246 
1,952,405 
1,173,732 

3,966,827 

a  Geol.  Foren.  i.  Stockholm  Forhandl.,  XV,  1893,  p.  409. 

6  Sundbaerg,  "  Sweden,"  Stockholm,  1904,  p.  758. 

c  Erdmann,  Mineral.,  1853,  p.  174. 

d  Min.  Jour.,  Nov.  30,  1907. 

e  Sundbaerg,  loc.  cit.  sup.,  p.  753. 


198 


EUROPE. 


The  available  returns  since  1900  are 


Year. 

Kg.  Fine  Gold. 

Ounces. 

Value. 
Sterling. 

1901 

627 

2013 

£8,558 

1902 

94  3 

3027 

12,872 

1903 

50-6 

1624 

6,907 

1904 

60-9 

1954 

8,313 

1905 

55  0 

1765 

7,594 

1906 

20-5 

658 

2,800 

RUSSIA. 


Finland. — The  first  gold  found  in  1836  in  Finland  la,y  in  frag- 
ments of  dolomite.  The  discovery  engendered  a  considerable 
amount  of  prospecting  in  succeeding  years  in  the  neighbourhood  of 
the  Kemi  and  Tornea  rivers  towards  the  Swedish  frontier.  A  fresh 
impetus  was  given  to  prospecting  by  the  discoveries  of  Thellef 
Dahll  in  the  Tana  and  other  rivers  of  the  Norwegian  province  of 
Finmark.  In  1868,  a  Finnish  prospecting  party  discovered  gold  in 
Finnish  Lapland,  along  the  upper  course  of  the  Ivalojoki  river,  which 
flows  through  Lake  Enara  into  Varanger  Fjord.  This  river  has 
since  furnished  nearly  all  the  gold  produced  from  Finland.  It  has 
never  been  very  rich,  the  best  return  being  obtained  by  a  party  of 
three  in  1869,  who  recovered  60  ounces  in  a  few  weeks.  The  year  of 
greatest  production  was  1871,  when  1,823  ounces  (56,700  grammes) 
were  obtained.  During  a  period  of  30  years  the  average  annual 
production  has  been  463  ounces  (14,396-7  grammes)."  From 
1870  to  1904  it  is  estimated  that  298,350  cubic  yards  (229,500  cubic 
m.)  had  been  washed  for  a  yield  of  14,284  ounces  (444,250  grammes) 
or  a  little  more  than  1  dwt.  per  cubic  yard.  In  1904  the  output 
was  only  63  ounces  (1,950  grammes),  and  in  1906,  92-8  ounces 
(2,887  grammes)  worth  9,095  Finnish  marks.  The  alluvial  gravels 
are  very  thin  and  narrow.  Their  depth  is  from  1J  to  6  feet,  and 
their  width  only  from  6  to  45  feet.fc  The  heavy  sands  contain 
magnetite  and  garnet  with  monazite  and  zircon. 

The  country  of  the  gold-quartz  veins,  the  degradation  of  which 
has  furnished  the  placer  gold  of  Finnish  Lapland,  is  a  granulite  that 
is  traversed  both  by  acidic  (quartz-porphyry)  and  basic  (diabase) 


aFircks,  Bull.  Com.  Geol.  de  Finlande,  Helsingfors,   XVII,  1906,  pp.   1-33.      (In 
English). 

"  Sarlin,     Meddelanden    fran    Industristyrelsen    i    Finland,    Helsingfors,    No,    32, 
1902,  p.  1. 


RUSSIA.  199 

dykes.  The  gangue  of  the  veins  is  quartz,  with  a  considerable 
admixture  of  siderite  and  calcite.  Haematite,  magnetite,  pyrite, 
and  chalcopyrite  are  associated  with  the  gold.  These  veins  have 
been  closely  examined,  but  none  of  any  size  or  value  have  as  yet 
been  found.  The  climate  of  Finnish  Lapland  is  exceedingly  severe, 
the  Ivalojoki  river  lying  five  degrees  within  the  Arctic  Circle.  The 
conditions  under  which  the  placers  occur  are  therefore  entirely 
comparable  with  those  of  Northern  Alaska. 

Olenetz  and  Archangel. — The  earliest  recorded  gold  dis- 
covery in  Russia  appears  to  have  been  made  in  1737  at  Voitsk  in 
the  Wyg  river,  in  the  Archangel  district,  where  auriferous  quartz- 
veins  occur  in  isolated  areas  of  talcose  schists  in  the  great  granite 
massif  of  North-Western  Russia.  The  schists  in  all  cases  are 
intruded  by  diabasic  rocks.  These  deposits  were  never  very  pro- 
fitable, and  were  abandoned  in  1794,  after  having  produced  a  little 
more  than  2,000  ounces  gold.  Two  gold-quartz  veins  are  also 
known  in  the  province  of  Olenetz,  about  30  miles  east-north-east 
and  east-south-east  respectively  of  Povenetz  on  the  northern  shore 
of  Lake  Onega.     These  were  discovered  in  1744.^ 

Ural  Mountains. — Long  before  the  conquest  of  Siberia  by  the 
Russians,  vague  stories  of  its  wealth  were  in  circulation  in  Western 
Europe,  but  despite  vigorous  search,  it  was  not  until  1743 
that  gold  was  found.  The  discovery  was  made  by  a  peasant 
in  a  quartz -vein  at  a  spot  close  to  the  junction  of  the  Pyshma  and 
Berezovsk  rivers,  some  seven  miles  from  Ekaterinburg.  Of  former 
workings  in  the  Urals  there  is  no  definite  information.  Gmelin,6 
who  journeyed  through  the  Urals  in  1733-1743,  describes,  however, 
ancient  narrow  and  cramped  workings,  presumably  for  gold.  They 
were  so  low  that  they  could  be  entered  only  by  crawling  on  the 
stomach.  Remains  were  found  of  miners  who  had  perished  in  a 
collapse  of  the  workings.  It  is  possible  that  some  of  the  gold 
of  ancient  Bactria  was  derived  from  the  Urals.  The  first  dis- 
covery, strangely  enough,  appears  to  have  been  of  vein-gold,  the 
placer  deposits  of  the  region  remaining  undisturbed  until  1774. 

Gold  occurs  throughout  the  whole  length  of  the  Ural  chain,  and 
more  particularly  on  its  eastern  flanks.  In  the  north  the  upper 
waters  of  the  Petchora,  Vishera,  Shigor,  and  Vychegda  flowing  west 
from  the  Urals,  all  carry  a  little  gold.  In  the  Petchora,  near  the 
northern  Troitzk,  platinum  is  associated  with  the  gold.  The  upper 
waters  of  the  Sossva,  which  flows  into  the  Obi  at  Berezov,  are  also 

a  Kokscharov,  Mat.  Min.  Russlands,  VI,  1870,  p.  350. 
b  "Reise  durck  Siberien,"  Gottingen,  1751-2,  III,  p.  299. 


200 


JV^ftt  =h'J.^-^ 


6  A    A,*  a.'        A, 

Ja/aaiA  ^ 


|t  v  Pi  •''I  a^-'a'* 

.,'  A,       A  , 


A  I  A  a 


i^  a»  A  a , 


A  A     a.4 


-  —si      '  I      -  •       '  ■  " 


Fig.   84.     Geological  Sketch  Map  of  the  Southern*  Urals. 

S.  Crystalline  schists.     0.  Gneiss,  granite,  syenite,  and  porphyry.     Di.  Diorite,  diabase,  and  porphyrite. 

Tf.  Greenstone  tuffs.     Sp.  Serpentine.     D.  Devonian.     C.  Carboniferous.     P.  Permo-Carboniferous. 

LT.  Lower  Tertiary. 


RUSSIA. 


201 


believed  to  carry  gold-gravels.  All  these  occurrences  are  alluvial. 
South  of  the  foregoing,  and  between  60°  and  62°  N.  lat.,  especially 
in  the  neighbourhood  of  Nikito-Ivdel,  are  numerous  occurrences 
associated  with  diabase,  diabase-porphyrite,  and  augite  porphyrite. 
Placer  gravels  are  widely  developed,  especially  on  the  Ivdel  and 
Wijai  rivers,  tributaries  of  the  Lossva/'  but  other  streams  to  the 
north  of  Petropavlovsk  are  also  auriferous. 


Fig.    65.     Geological   Sketch   Map    of   Neighbourhood    of   Ekaterinburg. 

G.  Granite  and  syenite.        D.  Diorite,  diabase,  and  basic  rocks.        8.  Crystalline  schists. 

L.  Lower  Devonian  Limestone.      B.  "  Beresite  "  dykes. 

The  most  northerly  goldfields  now  worked  on  an  extensive 
scale  are  near  Bogoslovsk,  where  the  placers  lie  along  the  tributaries 
of  the  Lossva  and  (southern)  Sossva  streams  that  flow  to  join  the 
Tavda.  The  gold  of  the  Bogoslovsk  placers  is  associated  with 
pebbles  of  augite-porphyry,  jasper,  clay-slate,  quartz,  and  grains 
of  haematite  and  magnetite.  Gold  is  found  in  situ,  near  Kopte- 
korskoi,  six  miles    from    Turinsk,  in    quartz  veins   in   serpentine. 


a  Federov,  Tscherm.  Mittheil,  N.F.,  XIV,  1894,  p.  86. 


202 


EUROPE. 


The  gravels  of  the  Lata  and  other  tributaries  of  the  Lobva  are 
auriferous.  Next  to  the  south  is  the  district  of  Likolai-Pavdinsk, 
where  are  small  placer  deposits  and  an  auriferous  vein  carrying 
pyrite  in  a  quartz  matrix.  It  is  situated  south  of  the  Suchogorsky 
iron  smelters. a  Near  Bissersk,  on  the  western  flank  of  the  Urals, 
gold-gravels  have  been  worked  since  1824.  Diamonds  have  at 
times  been  found  in  the  wash.  All  the  streams  in  the  neighbourhood 
of  Kushirnsk  carry  gold.  The  richest  appears  to  be  the  Uralicha. 
At  Nijni-Tagilsk  gold  is  found  on  both  sides  of  the  Tagil,  and  also 
between  the  Tagil  and  the  Nieva  river  next  to  the  south.  The  bed- 
rock of  these  placers  is 
talcose  and  chloritic  schist. 
The  gold-quartz  veins  of 
Neviansk  lie  partly  in  a  rock 
resembling  "beresite' 
(microgranite),  and  partly 
in  chlorite-schist.  The 
gold  occurs  in  thin  plates 
in  vughs  in  quartz. b 

The  gold  deposits  of 
Berezovsk,  among  the 
most  important  in  the 
Urals,  are  distributed  over 
an  area  of  246  square 
miles  (56  square  versts), 
near  the  Berezovsk  mill, 
about  7 1  miles  north-east  of 
Ekaterinburg.  They  were 
discovered  in  1745,  and 
have  been  worked  ever 
since.  The  surface  of  the 
country  is  undulating  and 
is  sparsely  timbered  with 
pine  and  willow.  The  rocks  are  mica-schists  and  muscovite- 
granite-schists,  now  largely  decomposed  to  a  soft  red  rock.  With 
the  schists  are  found  exposures  of  serpentine,  and  to  the  west 
a  peculiar  metamorphosed  dolomitic  limestone  (listvenite)  con- 
sisting of  magnesite,  siderite,  and  calcite.  The  schists  are 
traversed  by  a  network  of  almost  vertical  microgranitic  (beresite) 
dykes,  which  appear  to  be  connected  with  the  neighbouring 
granite  massif  of  Lake  Shartash.  The  beresites  are,  as  a 
rule,      much     altered,     and     vary      considerably      in      character. 


Fig.  86.     Plan  of  Gold-bearing  Quartz  Veinlets, 

STRIKING   E.    TO  W.,  LN   N.  TO   S.    BERESITE    (mICRO- 

granite)  Dykes,  Berezovsk,  Urals  (Posepny). 


a  Stahl,  Chem.  Centralblatt,  II,  1897,  p.  58. 

6  Von  Arzruni,  Zeit.  deutsch.  geol.  Gesell.,  XXXVII,  1885,  p.  873. 


RUSSIA.  203 

They  range  in  width  from  6  to  130  feet.a  Many  of  the  larger 
beresite  dykes  show  a  more  or  less  parallel  arrangement,  and 
some  are  persistent  for  a  length  of  more  than  5  miles  (8  km.). 
They  are  traversed  from  wall  to  wall  by  numerous  nearly  vertical 
veinlets  of  gold-quartz  of  a  thickness  of  a  few  inches  to  3  J  feet. 
Ordinarily,  veins  do  not  go  beyond  the  beresite,  but  they  are 
occasionally  found  in  the  schists  beyond  the  dyke  wall.  The 
origin  of  the  vein-fissures  has  been  ascribed  by  Posepny  to 
contraction  of  the  intrusive  rock  on  cooling,  an  explanation  that 
has  generally  been  accepted.  Purington,^  however,  shows  that 
two  systems  of  Assuring  traverse  the  whole  series,  but  that  these 
fissures,  owing  to  physical  conditions,  are  developed  much  more 
strongly  in  the  microgranitic  dykes  than  in  the  adjacent  meta- 
morphic  rocks.  The  fissures  strike  either  N.  80°  E.  or  N.  30°  W.  In  the 
neighbourhood  are  basic  dykes  that  carry  no  ore,  and  show  no 
evidence  of  having  been  crossed  by  the  above-mentioned  fissures. 
Purington,  therefore,  concludes  that  ore-impregnation  was  contem- 
poraneous with  or  was  directly  consequent  on  the  intrusion  of  the 
basic  dykes.  He  further  shows  that  the  gold-deposits  of  the  Urals 
are  remarkably  coincident  with  the  distribution  of  the  basic  rocks 
of  the  region. 

The  gold-quartz  of  Berezovsk  is  sometimes  compact,  sometimes 
porous,  and  generally  contains  pyrite.  Gold  is  found  either  free  in 
the  quartz,  or  contained  in  the  pyrite.  Associated  minerals  are 
numerous  :  chalcopyrite,  covellite,  galena,  magnetite,  aikinite 
(copper-bismuth  sulphide),  tennantite,  and  tetrahedrite,  with  deriva- 
tive minerals.  The  quartz  often  contains  acicular  crystals  of  a 
pale  green  tourmaline,  disposed  at  right  angles  to  the  walls.  The 
pyrite  may  contain  from  1 J  dwts.  to  1  ounce  gold  per  ton,  and  assays 
of  even  8  ounces  per  ton  have  been  obtained.  The  general 
tenor  of  the  Berezovsk  veins  is  some  8 J  dwts.  (13  grammes) 
per  metric  ton.  The  placers  of  Berezovsk  lie  on  the  same  rocks 
that  contain  the  gold-quartz  veins. 

Since  1885,  the  auriferous  veins  of  Pychminsk,  4J  miles  (7  km.) 
north-east  of  Berezovsk,  have  also  been  worked.  The  country  of 
the  veins  is  listvenite  (magnesite,  calcite,  and  breunerite)  and  ser- 
pentine arranged  in  more  or  less  parallel  bands,  all  being  traversed 
by  dykes  of  microgranite,  quartz-porphyry,  and  felsite.  Numerous 
gold-quartz  veins  occur  almost  entirely  in  the  intrusive  porphyry 
(diorite  of  Posepny)  and,  like  the  veins  in  the  beresite  of  Berezovsk, 
do  not  extend  appreciably  into  the  enclosing  country,  but  lie  trans- 

°  Karpinsky,  Guide  du  VII  Congres    Geolog.  Internat.,  V,  1897,   p.  42  ;    Posepny. 
Archiv.  fur  prakt.  Geol.,  II,  1895,  p.  499. 

b  Eng.  Min.  Jour.,  June  13,  1903,  p.  894. 


204  EUROPE. 

versely  across  the  dykes.  The  thickness  of  the  veins  is  from  2  to  3 
feet.  The  gold  is  accompanied  by  pyrite,  chalcopyrite,  galena,  and 
their  oxidation  products.  The  tenor  of  the  ore  varies  from  J  dwt. 
to  7  ounces  per  ton,  while  the  average  during  the  five  years  prior  to 
1898  was  17i  dwts.  (27  grammes)  per  metric  or  short  ton.a 

The  placers  of  Sysertsk  and  Kyshtimsk  further  south  have 
yielded  notable  quantities  of  crystallized  gold.6  (Figs.  13-34.) 
Succeeding  these,  but  after  a  considerable  interval,  come  the 
important  deposits  of  the  Miask  district,  where  the  auriferous 
placers  are  exceedingly  numerous  and  were  formerly  of  considerable 
richness.0  They  have  furnished  many  large  nuggets,  the  heaviest 
found  in  1842  weighing  1,158  ounces  (36  kg.). 

In  the  neighbourhood  of  Tcheliabinsk  and  some  10  to  13  miles 
south-west  of  that  town,  gold-quartz  veins  are  worked  in  a  highly 
dynamo-metamorphosed  hornblendic  granite.  In  the  region  there 
are  also  found  beresite,  porphyries,  diabase,  and  tuff.  The  country 
is  highly  faulted  and  the  lodes  are  filled  with  brecciated  matter 
traversed  by  white  opaque  quartz  stringers  and  veins  ranging  from 
8  inches  to  1\  feet  in  thickness.  The  oxidised  zone  extends  to  a 
depth  of  100  to  130  feet.  At  lower  depths  sulphides  and  arsenides 
make  their  appearance.  The  tenor  of  the  ore  varies  from  1J  to  6| 
dwts.  per  ton,  with  occasional  enrichment  to  an  ounce  per  ton.  In 
the  Verkhny -Uralsk  district  the  principal  mines  are  those  of  Semio- 
nowski-Prisk,  north  of  the  town  of  Verkhny- Uralsk.  The  region 
was  originally  worked  for  placer  gold,  but  now  produces  nearly 
all  its  gold  from  a  talcose  and  dolomitic  schistose  zone  of  alteration 
products  that  lies  between  serpentine  and  fine-grained  peridotite.^ 
Lenses  of  clean  white  quartz  occur  within  the  schistose  zone,  but  are 
always  barren,  and  the  gold  of  the  lode  is  distributed  mainly  through 
the  talcose-schist  band  in  the  crushed  zone.  The  outcrop  ore  was 
very  rich, yielding  as  much  as  3  ounces  per  pound  (6  pfund  per  pood). 
The  first  year  of  mining  produced  5,266  ounces  (163-808  kg.)  gold. 
A  similar  occurrence  is  met  with  at  Kamyschak,  where  the  talcose 
zone  lies  between  serpentine  and  hornblende-schist.  The  talcose 
rock  is  apparently  derived  from  the  weathering  of  the  serpentine. 
The  tenor  of  the  ore  here,  as  in  the  foregoing  occurrence,  diminishes 
materially  in  depth.  Tschernychew c  describes  a  gold-bearing  lode 
in  the  Poliakowski  mountains,  near  Balbuk,  in  which  the  gold  is 
finely  disseminated  through  the  mass  of  the  serpentine  and  quartz 

11  Karpinsky,  loc.  cit.  sup. 

h  Rose,  G.,    "  Reise,  &c,"  1842,  II,  p.  156. 

c  Posepny,  loc.  cit.  sup. 

d  Futterer,  Zeit.  fur  prakt,  Geol.,  1897,  p.  388. 

e  Mem.  du.  Com.  Geol.,  Petersburg,  III,  No.  4,  1889,  p.  389. 


RUSSIA. 


205 


veins  are  entirely  absent.  Quartz  veins  in  the  neighbourhood, 
however,  carry  fine  gold.  The  degradation  of  these  rocks  and  veins 
has     furnished     much     alluvial    gold.       At     Absakowa,    west    of 


C'     Placer    Workings 
JT    Ve  id    Mines 


Fig.  87.     Geological  Sketch  Map  of  the  Neighbourhood  of  Miassk  {Tschemycheu}). 

S.  Crystalline  schist.     SI  Slate.     G.  Granite  and  syenite.     D.  Diorite  and  diabase. 

Tf.  Greenstone  tuff.     Sp.  Serpentine. 

Verkhni-Uralsk,    auriferous    calcite    veins     containing    serpentine 
inclusions  lie  in  serpentine  near  its  contact  with  a    grey  meta- 


206  EUROPE. 

morphic  schist."  The  gold  often  occurs  as  thin  films  in  the  cleavage 
planes  of  the  calcite,  and  also  in  the  schistose  Assuring  of  the  adjacent 
serpentine.  Numerous  similar  poor  and  narrow  veins  occur  on 
the  eastern  slopes  of  the  southern  Urals. 

The  Kotchkar  mines  lie  50  miles  south-west  of  Miass.  Its  360 
to  400  auriferous  veins  lie  on  the  upper  waters  of  the  Kotchkara, 
Tchornaia,  Osseika,  Kamenka,  and  Sanarka.^  The  exploitation  of 
gold  in  this  region  dates  from  1844,  when  placers  were  discovered 
in  the  southern  portion  of  the  region.  The  veins  of  the  region  were 
first  opened  up  between  1863  and  1867.  In  1897  these  veins  were 
yielding  from  42,000  to  45,800  ounces  (1,300  to  1,425  kg.)  gold 
annually,  while  the  annual  placer  yield  was  only  from  9,600  to 
11,250  ounces  (300  to  350  kg.).  The  total  production  of  the  field 
from  1844  to  1897  was  about  1,512,979  ounces  (47,060  kg.),  of  which 
808,894  ounces  (25,160  kg.)  was  placer  gold.  The  greater  number 
of  veins  are  enclosed  within  an  area  of  20  square  miles.  The  country 
of  the  veins  is  a  fine-grained  grey  granitic  rock,  the  beresite  of 
many  writers.  Owing  to  intense  dynamic  metamorphism,  schists 
have  been  produced  in  the  granite  along  zones  of  shearing.  The 
intermediate  bands  of  granite  are  quite  solid,  and  show  no  signs  of 
schistosity.  The  gold-quartz  veins  lie  along  these  schistose  zones, 
and  in  strike  are  generally  parallel  with  them.  According  to 
Purington,c  auriferous  impregnation  is  here  directly  connected  with 
the  occurrence  of  two  peridotite  stocks.  Around  the  more  southerly 
of  the  two  the  richer  veins  are  grouped.  The  width  of  the  lode 
channels  may  range  from  3  to  20  feet,  but  that  of  the  quartz 
stringers  themselves  is  only  from  1  to  4  inches.  The  schistose  zones 
may  be  only  a  few  feet  apart,  or  may  be  separated  by  hundreds  of 
feet.  The  gangue  of  the  veins  is  a  grey  opaque  quartz  that  is  often 
chalcedonic  or  chloritic.  Associates  of  the  gold  are  mispickel, 
pyrite,  galena,  and  stibnite.  The  average  tenor  of  the  quartz  is 
3  to  8  J  dwts.  per  metric  ton.  Occasionally,  the  walls  are  sufficiently 
impregnated  with  auriferous  pyrites  to  be  worth  working.  Expe- 
rience has  shown  that  a  considerable  amount  of  secondary  enrichment 
has  taken  place  near  the  surface,  with  a  consequent  formation  of 
rich  pockets.  The  average  tenor  of  the  Ouspensky  outcrop  ore,  for 
example,  has  been  nearly  2  ounces  per  ton.  This  mine  was  in  1898 
the  best  developed  in  the  district,  with  a  shaft  400  feet  deep.  It 
had  to  that  year  produced  £570,000  gold  out  of  a  total  Kotchkar 
product  of  £5,833,000.     The  Troitzk  mine,  operated  by  an  English 

a  Futterer,  loc.  cit.,  p.  339. 

"  Wyssotsky,  Guide  du  VII  Congres  Geo!.  Internat.,  VI,  p.  2  ;    NitzeandPurington, 
Trans.  Am.  Inst.  M.E.,  XXVIII,  1898,  p.  24. 

c  Eng.  Min.  Jour.,  June  13,  1903,  p.  894. 


RUSSIA.  207 

company,  lies  in  this  district.  This  mine,  from  October  28th,  1906, 
to  January  13th,  1908,  milled  37,629  tons  ore  for  8,830  ounces  fine 
gold  worth  £37,268,  the  ore  milled  being  of  a  tenor  of  almost  exactly 
£1  per  ton. 

The  Orsk  goldfields  mark  the  southern  limit  of  the  gold 
occurrences  of  the  Urals.  Several  placer  deposits  are  worked. 
The  gold-quartz  veins  appear  to  occur  in  intrusive  basic  rocks, 
as  diorite  or  diabase-porphyrite,  or  in  tuffs  of  similar  rocks. a  An 
English  company  operating  in  this  district  was  in  1907  producing 
500  to  750  ounces  per  month,  but  ceased  operations  in  1908. 

Reviewing  the  auriferous  deposits  of  the  Urals,  it  may  be  said 
that  they  are  disposed  mainly  along  the  eastern  flanks  of  those 
mountains.  The  metamorphic  rocks  underlying  the  placers  are 
gneisses,  schists,  phyllites,  and  quartzites,  with  occasional  calcareous 
and  dolomitic  members  in  the  crystalline  schists.  The  massive 
rocks  are  granite,  syenite,  quartz-porphyry,  felsite,  diorite,  gabbro, 
norite,  diabase,  porphyrite,  and  pyroxenite.  Nearly  all  have  been 
subjected  to  intense  dynamic  metamorphism.  The  gold  in  the 
northern  portion  is  associated  with  acidic  intrusive  rocks  (micro- 
granite  or  beresite),  while  in  the  south  the  association  is  rather  with 
basic  rocks  :  diorites,  serpentines,  peridotites,  &c.  The  evidence 
available  shows  that  the  gold  disseminated  through  the  serpentines 
is  to  be  regarded  as  an  entirely  secondary  impregnation,  and  not 
as  a  primary  constituent  of  the  serpentine. 

The  placers  of  the  Urals  are  fairly  uniform  in  character.  Their 
average  thickness  is  only  from  1 J  to  3  feet,  with  a  maximum  of  1 2  to 
14  feet.  Their  average  length  is  from  20  to  50  yards,  and  may  reach 
one-third  of  a  mile.  The  Petchanka  placer  in  the  Bogoslovsk  district 
had,  however,  a  total  length  of  8  miles.  The  average  width  may 
be  estimated  at  from  20  to  45  yards.  They  are  occasionally  covered 
by  a  thin  soil,  but  more  ordinarily  lie  buried  beneath  a  barren  bed 
of  peat  and  soil  (tourbe),  which  may  vary  in  thickness  from  a  few  feet 
to  65  feet  or  more.  The  pay-streak  usually  rests  on  hard,  little- 
decomposed  rock  (plotik),  and  rarely*  on  a  "  false  bottom."  Every 
thalweg  and  stream  bed  lying  on  crystalline  rocks  with  auriferous 
veins,  may  contain  auriferous  alluvial  gravels.  The  richness  of  the 
placers  does  not,  however,  always  depend  on  the  nature  of  the 
adjacent  rocks  ;  the  richest  are  apparently  those  derived  from 
dioritic  or  talcose  crystalline  schist  areas,  while  those  arising  from 
the  denudation  of  gneiss,  granite,  or  mica-schist  are  much  poorer. 
The  distribution  of  the  gold  within  the  pay-streak  is  very  irregular, 
rich  layers,  and  poor  bands  alternating  in  most  cases.  The  general 
tenor  of  the  workable  Ural  placers  lies    between  10  and  50  grains 


a  Tschernyckew,  Russ.  min.  Gesell.,  XXIX,  1892,  p.  225. 


2<>S 


EUROPE. 


per  cubic  yard.  Higher  values  are  rarely  met  with,  and  then  only  in 
very  restricted  areas.  Nevertheless,  tenors  of  500  ounces  per  ton 
have  been  reached.  The  heaviest  nugget  obtained  in  the  Urals 
was  that  already  mentioned  as  weighing  1,158  ounces  (36  kg.).  It 
came  from  the  Tzarevo-Alexandrovski  placer  in  the  Miass  district. 
The  gold  in  the  pay-streak  is  almost  always  accompanied  by  magne- 
tite, more  rarely  by  ilmenite  and  chromite.  Platinum  is  often 
recovered  with  the  gold.  Zircon,  disthene,  and  diamonds  have  also 
been  found  in  the  wash.  The  total  length  of  the  Ural  placer  region, 
from  50  miles  north  of  Bogoslovsk  in  the  north  to  near  Orsk  in  the 
south,  is  more  than  660  miles. 

It  is  somewhat  difficult  to  obtain  separate  returns  for  European 
and  for  Asiatic  Russia.  Those  available  are  fragmentary,  and 
often  conflicting.  The  following  table  gives  the  available  yields 
for  recent  years  of  the  Russian  Empire  : — a 


Kg. 

Crude 

Value. 

Ye.ir. 

(Crude). 

Ounces. 

Sterling. 

1898 

. 

1,235,764 

£ 

1899 

38,8(38 

1,208,795 

1900 

38,796 

1,206,556 



1901 

39,140 

1,217,254 

4,651,682 

1902 

34,857 

1,120,678 

4,163,278 

1903 

35,271 

1,134,000 

4,145,967 

1904 

42,295 

1,382,481 

5,084,656 

1905 

33,542 

1,078,400 

4,569,778 

1906 

3,996,413* 

*  Rep.    Dir.    U.S.    Mint,    Washington,    1907. 

For  the  Urals  alone  the  annual  gold  yield  appears  to  vary 
between  250,000  and  300,000  ounces,  being  in  1900,  291,235  ounces  ; 
in  1902,  281,742  ounces  ;   and  in  1903,  264,898  ounces. 

Caucasus. — The  streams  of  the  Caucasus,  the  land  of  the  Golden 
Fleece  of  Jason  and  of  the  Argonauts,  have  been  found  singularly 
deficient  in  auriferous  deposits  in  recent  centuries.  The  existence 
of  gold  has  been  proved  in  isolated  districts,  but  nothing  beyond  the 
merest  traces  have  been  obtained.  The  Rion  river,  supposed  to  be 
the  Phasis  of  the  ancients,  was,  together  with  its  tributaries,  care- 
fully, but  fruitlessly,  prospected  for  gold  in  1854.6  Nevertheless,  the 
upper  waters  of  the  Rion,  60  miles  east  of  Sukhum-Kale  on  the 
Black  Sea,  are  marked  as  auriferous  on  the  map  of  the  mineral 
districts  of  Russia  compiled  by  de  Moeller. c  Other  gold-gravels  are 
situated  respectively  north  and  east  of  the  lake  of  Gotcha,  along  the 
mountain  ranges  between  the  Kur  and  Arax  rivers,  or,  measuring 

a  Dipl.  and  Consl.  Reports,  1900-1907. 

b  Ann.  des.  Mines,  Ser.  5,  III,  1853,  p.  830. 

cSt.  Petersburg,  1878. 


Russia.  209 


from  another  centre,  at  spots  some  50  miles  south  and  west 
respectively  of  Elizabethpol.  Bogdanovitch a  records  the  occur- 
rence of  gold  and  silver  midway  between  Nukha  and  Kuba  on  the 
slopes  of  the  great  Shalbuz-Dagh  mountain. 


a  Mem.  Geol.  Com.  Russ.,  XIX,  1902. 

o 


210 


ASIA. 


SIBERIA. 

As  early  as  1820  alluvial  gold-gravels  were  being  worked  in  the 
Altai  region.  Eighteen  years  later  all  Siberia,  with  the  exception 
of  the  Altai  and  the  Nerchinsk  circles,  still  retained  as  the 
personal  property  of  the  Tsar,  was  thrown  open  to  public  enterprise. 
Since  1837  the  gold  production  of  Siberia  for  the  periods  given  below 
has  been  as  follows  : — 


Ounces  (Crude). 

Ounces  (Crude). 

1837—1847 

1,065,451 

1898 

839,805 

1848—1857 

1,421,030 

1899 

828,917 

1858—1867 

1,265,424 

1900 

1868—1877 

2,105,825 

3901 

1878—1887 

5,023,855 

1902 

838,385 

a  1888— 1897 

9,346,197 

1903 

850,517 

The  present  annual  yield  of  Siberia  may  be  estimated  at 
800,000  to  900,000  ounces  of  gold. 

For  convenience  of  description,  the  auriferous  areas  of 
Siberia  are  enumerated  -as  follows  from  west  to  east  : 
Tobolsk- Akmolinsk  ;  Bokhara  (Russian  Turkestan) ;  Semipalatinsk- 
Semiretchensk  ;  Tomsk  ;  Atchinsk-Minusinsk  ;  South  Yenisei  ; 
North  Yenisei  ;  Transbaikalia  ;  Yakutsk  (Lena)  ;  Amur  ;  and 
Primorskoi  (Maritime  Province). 

The  first  three  areas  are  widely  separated  geographically,  each 
group  being  itself  composed  of  small  isolated  placers.  The  Tomsk, 
Atchinsk,  and  Minusinsk  districts,  on  the  other  hand,  together  form 
a  compact  auriferous  district  divided  only  politically,  and  lying, 
for  the  most  part,  south  of  Krasnoiarsk,  a  town  on  the  Yenisei  river 
and  also  on  the  Trans-Siberian  Railway.  North  of  this  area,  on  the 
right  bank  of  the  Yenisei,  and  between  the  Podkamennaia-Tunguska 
and  the  Angara  tributaries,  lies  the  Yenisei  group.  With  the  excep- 
tion of  the  western  portion  of  Transbaikalia,  lying  south  of  the  south- 
western end  of  Lake  Baikal,  all  the  remaining  districts  (Eastern 
Transbaikalia,  Lena,  Amur,  and  Primorskoi)  form  one  con- 
tinuous auriferous  area  stretching  east  as  a  fairly  narrow  band 
from  Lake  Baikal  to  the  south-western  shores  of  the  Sea  of  Okhotsk. 

a  Glasser,  Annales  des  Mines,  XVIII,  Ser.  IX,  1900,  p.  9. 


SIBERIA.  211 

This  belt  may  be  termed  the  Eastern  Siberian  field,  all  the  other 
districts  to  the  west  forming  the  less  important  Western  Siberian 
field.  The  following  comparative  table  shows  the  yields  in  average 
years  of  these  two  areas  : — 


1897. 
Ounces. 

1898. 
Ounces. 

1899. 
Ounces. 

Eastern  Siberia 

Western  Siberia 

(345,449 
167,715 

680,094 
159,711 

652,779 
176,138 

The  Siberian  placers  are  Recent  or  Pleistocene.  They 
are  all  above  sea  level,  ranging  as  high  as  1,850  feet  in  the 
Alatau  mountains,  and  to  2,300  feet  in  the  valleys  of  the  Olekma, 
and  in  the  Yenisei  district.  Many,  especially  in  the  Lena  district, 
and  in  the  Zeia  branch  of  the  Amur,  are  contained  in  or  are  covered 
by  perpetually  frozen  gravel.  Of  late  years,  considerable  progress 
has  been  made  in  dredging  in  the  Urals  and  in  Siberia.  During 
1906-7  there  were  in  all  some  40  dredges  at  work  in  the  Russian 
Empire.  Returns  were  obtained  for  the  working  season  of  1906 
from  32  of  these.  The  aggregate  amount  of  gold  and  platinum 
recovered  by  dredging  was  43,081  ounces,  of  which  36,609  ounces 
were  gold,  and  6,472  ounces  were  platinum.  The  largest  individual 
return  came  from  a  dredge  in  the  Ural  district,  that  saved  during 
the  season  of  175  days,  3,328  ounces  from  207,970  cubic  yards. 
Dredging  operations  have,  on  the  whole,  been  unprofitable,  owing 
apparently  to  defective  machinery  and  to  lack  of  experience.  The 
average  yield  per  dredge  calculated  from  32  dredges  giving  returns 
for  1906  is  as  follows  : — a 

Working  days  of  season         ...  ...  ...          ...  173 

Working  hours  of  season        ...  ...  ...          ...  2,837 

Gravel  washed             ...          ...  ...  cubic  yards  159,537 

Gold  and  platinum  extracted  ...  ...ounces  1,346 

Average  yield  per  cubic  yard  ...  ...  grains  4-2" 

Tobolsk-Akmolinsk. — The  placers  .of  the  Tobolsk- Akmolinsk 
district  are  grouped  in  a  small  area  to  the  east-south-east  of  the 
village  of  Kokchietav,  which  lies  about  170  versts  (113  miles)  south 
of  Petropaulovsk.     They  are  neither  extensive  nor  rich. 

Bokhara. — The  Bokhara  khanate  lies  immediately  to  the  north 
and  north-east  of  Afghanistan.  Its  gold  deposits  have  been  washed 
for  centuries  by  the  Sarts,  the  semi-nomadic  inhabitants  of 
the  region.  The  known  auriferous  placers  lie  in  Eastern  Bok- 
hara,   along    the    courses    of    the    Wahsch,    Kizil-Su,    Mazar-Su, 

aBogovin,  Eng.  Min.  Jour.,  Aug.  17,  1907. 

^  This  figure  is  given  asyl0125  ounces  in  the  original  paper. 


I'll' 


ASIA. 


Yak-Su,  and  the  Ravno  streams,  all  eventually  falling  into 
the  Panj  River  on  its  right  or  northern  bank.  The  Pan] 
separates  Bokhara  from  Afghanistan.  Below  its  junction  with 
the  Wahsch,  this  river  is  known  as  the  Amu-darya  or  Oxus.  It  also 
is  auriferous,  at  least,  as  far  down  its  course  as  the  "  Golden 
Isle,"  near  Awadje,  north-east  of  Balkh.  The  "  Golden  Isle  "  is 
some  165  miles  (250  versts)  from  the  high-level  gravels  that  furnish 
the  fine  gold  of  the  Kizil-Su. 

The  general  geology  of  the  country  is  simple.     The  great  moun- 
tain ranges  in  the  east  and  south-east  are  areas  of  metamorphic 


/?    " 


'Andijtti 


Xhojtnd 


*    /a    ft     C     H 


Fig.   88.     Geological  Sketch  Map  of  Auriferous   Area,  Bokhara  (Levat). 

1.  Granite,  gneiss,  and  mica-schist.      2.  Fusulina  limestone  (Carboniferous).     3.  Trias. 
4.  Cretaceous  shales.       5.  Tertiary   clays.       6.  Auriferous   conglomerates.       +   Placer-deposits. 

and  plutonic  rocks,  while  the  lower  ranges,  together  with  the  plains 
to  the  north,  are  made  up  of  little-disturbed  and  generally  horizontal 
Cretaceous  and  Tertiary  strata.  The  original  source  of  the  gold 
appears  to  have  been  small  veins  in  the  metamorphic  schists  of  the 
Altai  mountains.  A  gold-quartz  vein  is  known  and  has  been 
worked  near  Dorsch.re  During  the  erosion  and  degradation 
of  these  mountains  in  Eocene  times  great  beds  of  conglomerates 
with   associated  placer  gold   were   formed  in   the    lower    courses 


a  Von  Krafft,  Zeit.  fur  prakt.  Geol.,  1899,  p.  37. 


SIBERIA.  213 

of  the  mountain  streams  far  from  the  parent  veins.  From 
the  varied  character  of  the  boulders  found  in  the  conglomerate 
the  then  existing  streams  appear  to  have  drained  a  large  stretch  of 
country.  The  predominant  rocks  are  green  diabase-tuff,  red 
felso-porphyrite,  diorite,  porphyritic  diabase,  porphyrite,  gneiss, 
amphibolite,  quartz-schist,  quartzite,  and  various  sedimentary 
rocks.  The  cement  is  calcareous  or  arenaceous,  or  at  times,  calcareo- 
arenaceous.  Opinions  are  divided  as  to  the  method  of  formation 
of  the  conglomerates,  Levat,  from  whom  most  of  our  information 
on  this  region  is  derived,"  being  firmly  convinced  that  they  are 
glacial  in  origin.  The  gold  is  contained  in  the  cement,  nearly  always 
as  flattened  plates,  and  rarely  as  nuggets.  The  tenor  of  the  older 
conglomerates  is  low,  but  long-continued  erosion  and  concentration 
by  subsequent  streams  has  furnished  workable  river  gravels,  both 
high-level  and  also  in  the  beds  of  the  existing  streams.  The 
auriferous  conglomerates  have  a  considerable  development  on  the 
western  flanks  of  the  Darwaz  chain,  where  they  cover  hundreds  of 
square  miles.  Their  maximum  thickness  is  perhaps  2,000  feet. 
The  main  conglomerate  band  runs  in  a  north-east  direction,  from  a 
point  some  15  miles  east  of  Kolab  to  the  north  of  Kali-i-khumb, 
where  it  strikes  due  east.  Two  minor  bands  occur  on  the  east  and 
west  of  the  main  band,  at  Ravno  and  at  Obi-Sanghi-Khergov 
respectively.  The  principal  placer  workings  lie  near  or  on  the  con- 
glomerate beds  in  the  old  river  terraces,  and  in  the  present  stream 
beds.  The  former,  being  easily  drained,  have,  as  a  rule,  been 
worked  and  re-worked  many  times  by  the  Sarts,  and  now  offer  but 
little  scope  for  industrial  development.  All  deposits  below  water- 
level  are  virgin,  and  are  apparently  fairly  rich.  At  a  placer  deposit 
leased  by  M.  Pakorski,  the  overlying  gravels  already  worked  by  the 
Sarts  to  a  depth  of  14  feet  (2  sajenes)  contained  only  1  71  grains  per 
cubic  yard  (2|  dolis  per  100  poods).  At  the  water-level  the  gold 
content  rises  to  20  •  6  to  27  •  4  grains  per  cubic  yard  (30  to  40  dolis  per 
100  poods),  while  at  a  depth  of  42  feet  (6  sajenes)  a  tenor  of  65-78 
grains  per  cubic  yard  (1  zolotnik  per  100  poods)  was  reached,  and 
even  then  bed-rock  had  not  been  reached.  The  gold  of  the 
gravels  occurs  in  small  flattened  grains.      Nuggets  of  more  than 

13  to  16  dwts.  (5  to  6  zolotniks)  are  rare.  The  gold  is  from  920 
to  927  fine. 

The  washings  conducted  by  Levat  showed,  on  the  whole,  low 
values.       At  the  Nicholas    placer  on   the    Mozar-Su   he  obtained 

14  4  grains  per  cubic  yard  (1-218  grammes  per  cubic  metre); 
at    Obi-Sanghi-Khergov,   the    conglomerate    carried    usually    not 

a  Bull.  Soc.  Geol.  de  France,  II,   Series  4,  1902,  p.  447  et  scq.  ;     Ann  ales  des  Mines, 
III.  Series  10,  1903,  p.  201. 


214  ASIA. 

more  than  3£  grains  per  cubic  yard  ( •  275  grammes  per  cubic 
metre).  In  the  Safet-darya  the  alluvials  had  been  worked 
for  some  six  years  prior  to  1902  by  Russian  concessionaires. 
There  the  lower  beds  averaged  41  grains  per  cubic  yard 
(6-4  francs  per  cubic  metre).  The  Russian  workings  in  1902 
were,  however,  exceedingly  primitive.  The  Tibi-darya  and  the 
Sagri-datch  placers  on  tributaries  of  the  Klungau,  or  Wahsch,  gave 
prospects  of  only  1  -3  grains  per  cubic  yard  (20  centimes  per  cubic 
metre). 

The  native  (Sart)  methods  of  working  and  washing  are  crude. 
The  placers  are  drained,  where  possible,  by  long  adit  levels,  that  are 
ventilated  by  a  series  of  inclined  shafts  carried  down  to  the  drainage 
level  from  the  surface,  a  new  ventilation  shaft  being  sunk  on  the 
course  of  the  adit  whenever  the  face  becomes  too  far  advanced  to 
be  served  by  the  existing  shaft.  The  gravel  is  carried  by  boys  from 
the  bottom  of  the  inclined  shafts  to  washing  trays  at  the  surface, 
where  the  sand  is  washed  over  felts.  Sometimes  fleeces  or  camel 
skins  are  used,  in  which  case  the  hair  of  the  former  is  cut  to  a  uniform 
length  of  •  4  inches  and  the  fleece  is  further  often  transversely  ribbed 
every  2  inches  by  shaving  to  the  skin  for  a  width  of  I  inch. 
Miniature  riffles  are  thus  formed,  assisting  in  the  retention  of  the 
gold.  Such  a  fleece  resembles  the  long-pile  velvet  strakes  com- 
monly used  on  modern  dredges.  The  minimum  earnings  of  the 
Sarts  appear  to  be  sixpence  per  diem.  The  gold  yield  of  Eastern 
Bokhara  was  estimated  in  1899  at  £20,000  to  £30,000  per  annum.8 

Semipalatinsk-Semiretchensk. — These  districts  lie  to  the  north- 
east and  south-east  respectively  of  Lake  Balkash.  The  placer 
deposits  of  the  former  are  disposed  along  the  Irtish  River,  between 
Lake  Zaisan  and  the  town  of  Ust-Kamenogorsk,  south-east  of  Semi- 
palatinsk.  The  deposits  are  thin  and  poor,  and  would  be  unworkable 
were  it  not  for  the  abundance  and  cheapness  of  the  Kirghiz  labour. 
Gravels  containing  as  little  as  4  grains  per  cubic  yard  can  thus 
be  worked.  In  1897  about  1,200,000  cubic  yards  of  sand  were 
treated  for  16,846  ounces  of  gold,  or  nearly  7  grains  gold  per  cubic 
yard.  More  than  5,000  Kirghiz  were  employed  on  the  various 
claims/' 

The  Semiretchensk  placers  are  scattered  along  the  head-waters 
of  streams  flowing  north-west  into  Lake  Balkash.  They  have  no 
present  importance. 

Tomsk. — The  Tomsk  mining  field  includes  the  Altai  and  Mariinsk 
districts  in  Tomsk  proper,  together  with  the  Atchinsk,  Minusinsk, 

a  Rickmers  Geog.  Jour.,  XIV,  1899,  p.  606. 
"  Glasser,  loc.  cit.  sup  ,  p.  45. 


SIBERIA. 

and  Yenisei  districts  in  Yeniseisk, 
district  from  1900-1904  was  : — a 


215 


The  production  of  this  mining 


Year. 

Tons. 

Ounces. 

Total  Ounces. 

1900...  ( 
1901...  J 
1902...  5 
1903...  -J 
1904...  i 

Quartz 
Gravel 
Quartz 
Gravel 
Quartz 
Gravel 
Quartz 
Gravel 
Quartz 
Gravel 

25,081 
7,201,455 

26,944 
7,101,045 

25,483 
5,493,823 

41,766 
5,585,976 

61,420 
6,842,227 

9,976 

171,816 
25,120 

171,929 
26,811 

118,195 
38,735 
91,569 
29,654 
81,096 

?-     181,792 
\     197,049 
\     145,006 
|     130,305 
\     130,750 

It  therefore  appears  that  the  yield  from  alluvial  mining  is 
steadily  diminishing,  while  that  from  quartz  mining  is  increasing. 

Altai. — The  Altai  district  lies  on  the  northern  slopes  of  the 
Altai  mountains,  and  near  the  boundary  of  Eastern  or  Chinese 
Turkestan.  A  great  part  of  the -mineral  area  is  the  private  property 
of  the  Tsar,  and  is  administered  by  the  Cabinet.  Placers  open  to 
the  public  are  either  on  the  tributaries  of  the  Abakan,  flowing  into 
the  Yenisei  near  Minusinsk,  or  on  the  tributaries  of  the  Tom 
(Taidon,  Ters,  Oos,  Mras,  and  Kondom).  From  these,  in  1897,  some 
1,280,000  cubic  yards  of  gravel,  yielding  48,225  ounces  gold,  were 
washed.  The  average  tenor  was  therefore  about  18  grains  per  cubic 
yard. 

The  placers  administered  by  the  Cabinet  are  on  the  affluents 
of  the  Biya,  a  tributary  of  the  Ob.  These  yield  about  5,000  ounces 
per  annum.  With  the  Altai  district  may  be  taken  the  Mariinsk  dis- 
trict, where  gravel  deposits  are  worked  on  the  Kiya  and  Tela  streams, 
tributaries  of  the  Chulim.  In  this  district  a  quartz  vein  furnished 
in  1897  about  650  ounces  of  gold,  while  in  1904  the  Sixth  Berikal  gold- 
quartz  mine  crushed  9,477  tons  for  a  yield  of  9,460  ounces,  and  the 
G.  M.  Miller  mine,  also  in  the  Mariinsk  -district,  crushed  4,358^tons 
for  1,934  ounces. 

The  following  table  (Loranski)  shows  the  relative  importance  of 
the  principal  streams  of  the  Altai  and  Mariinsk  districts  during 
1896  :  — 


River  System. 

Cubic  Yards 
Treated. 

Number  of  Mines. 

Total  Yield. 
Sterling. 

Value  per  Cubic- 
Yard. 

Kiya      

Chorni  Oos  ... 
Byeli  Oos 

311,000 

167,000 

87,000 

75 
24 
13 

£47,700 

15,833 

9,792 

s.      d. 
2  11 

1  8 

2  3 

ftTovey,  Eng.  Mm.  Jour.,  Sept.  29,  1906,  p.  577. 


216  ASIA. 

The  stripping  necessary  averaged  about  10  feet,  while  the  pay- 
dirt  varied  in  depth  from  5  to  8  feet.  Much  deeper  gravels  occur 
in  the  Byeli  (White)  Oos.  The  working  season  in  this  region  is  from 
the  end  of  April  to  the  end  of  October,  or  six  months,  and  is  therefore 
longer  than  in  most  other  parts  of  Siberia.  The  bed-rock  of  the 
placers,  as,  for  example,  on  the  Blagodatny  stream,  is  mica-schist 
intruded  by  numerous  diorite  dykes.  The  gold  probably  comes 
from  minute  veinlets  in  the  neighbourhood.  At  the  head  of  a 
tributary  of  the  Byeli  Oos,  viz.,  The  Sorela  Oos,  from  which  more 
than  £1,000,000  of  gold  was  taken  in  the  early  days  of  Siberian  gold- 
washing,  the  mountains  are  of  diorite,  but  graphitic  slates  and  fine- 
grained porphyries  also  occur.  Gold-quartz  veins  are  numerous  in 
the  diorite. 

Little,  however,  can  be  said  about  the  primary  gold  deposits 
of  the  Altai  and  Mariinsk  districts,  since  up  to  the  present  time  they 
have  been  but  cursorily  examined.  Prof.  Zaitzeff,  in  1900,  found 
native  gold  in  diorite  at  the  head  of  the  Fyedorovski  stream,  a 
tributary  of  the  Chulim  river.  No  quartz  vein  occurred  within 
500  feet  of  the  gold  deposit,  but  there  was,  quite  near,  a  basic  dyke, 
that  was  perhaps  a  peridotite.  A  thousand  feet  away,  productive 
gold-quartz  veins  have  been  worked."  Korotkoff,^  in  describing  the 
gold-quartz  veins  of  the  Birikoulski  mine,  Mariinsk  district,  points 
out  the  presence  of  lollingite  (Fe  As2),  together  with  blende  and  galena. 
This  mine  was  not  discovered  until  1901,  though  its  placers  had 
yielded  abundantly  for  15  years  previously. 

Atchinsk-Mimisinsk  Districts. — These  are  in  Southern 
Yeniseisk,  south  of  Krasnoiarsk.  They  contain  several  gold- 
quartz  mines.  In  the  Atchinsk  district  the  Joannovski  (Podvint- 
zeff)  veins  lie  in  a  fine-grained  greenish  diabase.  The  mine  is  on  the 
left  bank  of  the  Bezimian  stream,  a  tributary  of  the  Saral-Oos.  It 
was  discovered  in  Sept.,  1899,  and  work  was  commenced  on  it  in 
1900.  The  first  crushings  yielded  from  350  tons  about  22  dwts.  per 
ton,  a  tenor  not  sustained,  since  later  crushings  fell  to  16  dwts. 
per  ton.  The  bullion  obtained  was  788  fine.  The  lode  out-cropped 
on  the  steep  mountain-side,  and  was  from  16  to  23  feet  in  width, 
but  bands  of  country  within  the  vein  reduced  the  width  of 
crushing  quartz  to  5  to  8 J  feet.  The  quartz  is  richest  nearest  the 
walls.  Another  vein  in  similar  rock  occurs  in  the  neighbouring 
Toumani  mine.c 

In  the  basin  of  the  Byeli-Oos,  south-east  of  Tchebaki,  is  the 
Ivanitzki  or  Bogom-Darovanni  ("Gift  of  God")  mine.  It  was  dis- 
covered in  1896,  and  from  1898  to  May,  1902,  had  produced  £60,000 

«  Brown,  Trans.  Amer.  Inst.  M.E.,  XXXIV,  1904,  p.  786. 

b  Bull.  Soc.  Oural,  XXV,  1905,  p.  69. 

c  Bordeaux,  Ann.  des  Mines,  II,  Ser.  X,  1902,  p.  505. 


SIBERIA.  217 

gold.  The  vein  is  in  syenite,  and  carries  epidote,  calcite,  pyrite, 
and  carbonates  of  copper.  The  auriferous  band  is  from  20  to  23 
feet  thick,  but  the  quartz  veins  within  it  themselves  make  up  a 
total  thickness  of  only  3  to  10  feet.  During  the  foregoing  period 
10,000  metric  tons  were  raised  and  crushed  for  a  yield  of  16,720 
ounces,  or  a  little  more  than  H  ounces  per  ton.  In  the  Minusinsk 
district  the  principal  mines  are  those  of  Kuznetzoff,  lying  about 
midway  between  the  towns  of  Tchebaki  and  Minusinsk.  The 
Kuznetzoff  mines  are  on  a  small  tributary  of  the  Tibika,  which 
itself  joins  the  Uibaka,  a  tributary  of  the  Yenisei.  Numerous 
veins  occur,  of  which  the  majority  are  in  muscovite-granite.  One, 
however,  is  in  a  hornblende-mica-gneiss.  The  majority  are  small. 
Zaitzeffa  groups  the  veins  of  the  Atchinsk-Minusinsk  region  into 
two  series  coursing  at  right  angles,  one  series  running  meridionally 
and  the  other  east  and  west.  The  Bogom-Darovanni  mine  of 
Minusinsk  (named  after  that  already  mentioned  of  Ivanitzki  in 
the  Atchinsk  district)  is  one  of  the  best  in  the  region.  Its  output 
for  1904  was  8,874  tons  for  10,649  ounces  or  1  •  2  ounces  per  ton. 
Wages  are  low,  and  labour  good. 

Yenisei. — The  Yenisei  auriferous  area,  as  already  has  been 
stated,  lies  between  the  Podkamennaia-Tunguska  and  the  Angara 
rivers,  both  tributaries  on  the  right  bank  of  the  great  Yenisei  river. 
Explorations  were  first  actively  undertaken  here  in  1840.  From 
that  year  to  1900,  a  period  of  60  years,  the  Yenisei  placers  had 
produced  about  14,146,000  ounces  gold.  In  1857,  their  yield  was 
643,000  ounces.  Thereafter  their  decline  was  rapid,  falling  in  the  last 
years  of  the  nineteenth  century  to  80,000  to  100,000  ounces  per 
annum.  The  decline  was  due  entirely  to  the  exhaustion  of  the  more 
readily  accessible  placers.  At  the  present  time  washings  are  being 
conducted  in  gravel  of  a  tenor  of  less  than  9  grains  per  cubic 
yard.  In  the  early  days  of  Yenisei  mining  the  yield  per  cubic 
yard  often  rose  to  16  dwts.  The  richest  gravels  worked  in  1897 
were  those  of  the  Udoronga  Valley,  of  a  tenor  of  some  2  dwts.  per 
cubic  yard.k  The  south  Yenisei  portion  of  the  above  district  lies 
between  the  Great  Pit  and  the  Angara  rivers.  Its  placers  are 
developed  along  the  upper  waters  of  the  various  northward-flowing 
tributaries  of  the  Great  Pit  (Gorbilok,  Penchanga,  &c),  and  also 
along  the  upper  courses  of  the  Uderei'a,  Udoronga,  Fvibnaia,  Mourzh- 
naia,  and  Tatarskaia,  all  the  members  of  the  latter  group  eventually 
flowing  southward  to  join  the  Angara.  The  bed-rock  is  largely 
composed  of  argillaceous  and  quartz-schists,  fairly  pyritous  in  bulk. 
Massive  granites  and  diorites  also  occur.     Meisterc  reports  that  the 

°  Centralblatt  fur  Mineral.,  XXXIV,  1901,  p.  137. 

6  Glasser,  Ann.  des  Mines,  XVIII,  Ser.  IX,  1900,  p.  36. 

c  Com.  Geo!.  Russ.,  I,  1900,  p.  8G,  Yenisei. 


218  ASIA. 

granites  and  metamorphic  schists  of  the  Uderei'a  and  Udoronga  are 
traversed  by  diabase  dykes.  Quartz  veins  are  numerous  through  the 
country.  Some  are  auriferous,  notably  in  the  valley  of  the  Ribnai'a 
north  of  Ribinskoi,  and  also  on  the  right  bank  of  the  Angara,  east  of 
Blokhino.  They  are,  however,  of  fairly  low  grade,  averaging  in  small 
veins  about  8  dwts.  per  ton.  Meister"  concluded  that  the  placers 
of  the  Great  and  Little  Mourozhna'ia,  Tchernai'a,  Tatarka,  and  Rib- 
nai'a, had  derived  their  gold  from  similar  veins  in  the  adjacent 
argillaceous  schists.  The  argillaceous  schists  without  pyrite,  in 
the  region  south-west  of  Yeniseisk,  contain  no  gold,  while  those 
impregnated  with  pyrite  contain  as  much  as  6  grains  per  ton  (20 
dolis  per  100  poods). 

All  the  placers  so  far  exploited  appear  to  be  of  recent  origin, 
and  occupy  the  bottoms  of  existing  valleys.  Generally  they  are 
shallow,  and  require  but  little  stripping.  The  yield  per  cubic 
yard  would  appear  to  vary  between  5  and  18  grains.  Much  of  the 
poorer  gravel  is  available  for  dredging.  The  native  placer  industry 
is  now  of  little  importance  in  the  Penchanga,  Gorbilok,  and  Ichimba 
rivers. 

The  North  Yenisei  district  is  situated  on  the  east  of  the 
Yenisei  river  in  the  upper  basins  of  the  Tei'a  and  Kalami  rivers, 
tributaries  from  the  south  of  the  lower  Podkamenna'ia-Tunguska. 
Its  rocks,  like  those  of  the  southern  Yenisei  field,  are  gneisses,  mica- 
schists,  and  amphibolites  with  ancient  sedimentary  rocks.  These 
are  traversed  by  small  dykes  of  granitite  and  diabase.  Gold-quartz 
veins  occur  in  the  schists,  but  gold  is  also  found  in  the  schist  rock 
itself/'  In  1902,  Jacewski c  found  that  a  highly  pyritous  (1  to 
1-33  per  cent.)  biotite-quartz-schist  of  the  Teisskai'a  Series  was 
auriferous  to  the  extent  of  14  grains  per  ton  (-00008  per  cent.). 
A  tourmaline-bearing  gneiss  yielded  7  grains,  while  a  conglomerate 
with  schist  pebbles  gave  from  7  grains  to  3  dwts.  gold  per  ton.  The 
problem  whether  the  gold  lay  in  the  cement  or  the  pebbles  remained 
unsolved.  The  most  important  placers  now  being  worked  in  the 
North  Yenisei  field  are  in  the  Tei'a,  Enachimo.  and  Kalami  rivers. 
Their  production  is  not  great. 

Transbaikalia. — The  Transbaikalia  (Zabaikalskai'a)  province 
is  situated  between  Lake  Baikal  and  the  Manchurian  frontier.  The 
minerals  of  the  greater  portion  of  the  province  are  the  private 
property  of  the  Tsar.  The  silver  mines  of  Nerchinsk  have  been 
worked  since  1703.  From  that  year  to  1870  they  had  yielded  more 
than  400  tons  (422,314  kg.)  of  silver.     With  the  silver  was  associated 

f(Ib.,  Ill,  1902,  p.  37,  Yenisei. 

b  Jacewski,  Com.  Geol.  Russ.,  I,  1900,  p.  33,  Yenisei. 

''  Loc.  cit.  Ill,  1903,  p.  78,  Yenisei. 


SIBERIA.  219 

a  very  small  proportion  of  gold,  which,  nevertheless,  for  the  same 
period  amounted  to  no  less  than  43,274  ounces  (1,346  kg.). 

Within  the  province  there  are  three  principal  gold-quartz 
mining  centres,  viz.,  Onon,  Nerchinsk,  and  Chilka.  The  Onon 
deposits  have  been  described  in  detail  by  Levat."  They  lie  in  a 
region  of  slates  and  shales  traversed  by  numerous  igneous  rocks,  of 
which  the  chief  types  are  granite,  aplite,  syenite,  diorite,  and  kersan- 
tite.  The  gold-quartz  veins  occasionally  pass  from  the  granites 
into  the  slates.  At  Khangarok  the  veins  were  in  1902  being  worked 
by  two  companies,  viz.,  the  Bielogolovi,  and  the  Sabachnikoff  at 
Baian-Zurga.  The  principal  veins  of  the  former  company  are  in  the 
slates  (schists),  near  their  contact  with  granite,  the  latter  rock 
also  containing  numerous  small  veins.  The  thickness  of  the  main  vein 
varies  from  a  few  inches  to  3  feet.  Its  tenor  may  be  as  high  as  an 
ounce  per  ton,  but  from  the  following  figures  its  average  tenor 
appears  to  be  in  the  neighbourhood  of  7  dwts.  From  1879  to  1887. 
66,450  metric  tons  were  treated  for  23,627  ounces  (727  kg.)  gold. 
For  the  next  ten  years  the  mines  were  closed,  but  in  the  five-year 
period  of  1897-1901,  a  further  3,734  ounces  gold  were  obtained,  the 
tenor  of  the  quartz  varying  from  3 h  to  7^  dwts.  per  ton.  The  vein 
has  been  worked  for  a  length  of  450  feet.  The  Sabachnikoff  Company 
worked  a  vein  at  Baian-Zurga,  in  slate,  but  also  near  a  granite 
contact.  The  vein  was  from  4  inches  to  2J  feet  in  thickness  and 
appeared  to  average  about  12 J  dwts.  per  ton,  2,446  metric  tons  in 
1886-7  having  produced  1,513  ounces  (46,550  kg.). 

A  gold-quartz  vein  has  been  worked  at  Oloviannaia,  nearer 
Nerchinsk.  At  Dalmatchik  in  the  Chilka  district,  north  of  Nerchinsk 
an  auriferous  syenitic  vein  occurs  in  the  granite. b  Along  the  contact 
of  the  two  rocks  there  runs  a  thin  vein  of  galena.  The  auriferous 
band  varies  in  thickness  from  2  to  8  feet,  and  appears  to  be  worth 
about  17  dwts.  per  ton. 

The  Kluchi  mine  is  worked  by  a  subsidiary  company  of  the 
Nerchinsk  G.M.  Co.,  the  latter  holding  a  general  concession  from  the 
Private  Cabinet  of  the  Tsar.  The  lode  formation  consists  of  a  highly 
altered  and  silicified  quartz-porphyry,  mineralised  with  pyrite  and 
gold.  From  July,  1905,  to  the  end  of  Aug.,  1906,  5,214  tons  treated 
gave  2,420  ounces  with  tailings  reported  to  average  8  dwts.  9  grains, 
indicating  a  total  tenor  of  17  dwts.  16  grains  per  ton. 

Auriferous  placers  are  scattered  throughout  the  Transbaikalia 
province.  The  majority  have  been  known  for  many  years.  In  1897, 
more  than  two-thirds  of  the  total  gold  produced  (77,803  ounces) 
came  from  the  Emperor's  private  mines,    of  which  10  were  being 


a  "  L"or  en  Siberie  orientale,"  Paris,  I,  1897. 

b  Bordeaux,  Ann.  des  Mines,  II,  Ser.  X,  1902,  p.  537. 


220 


ASIA. 


worked.  They  yielded  56,875  ounces  from  600,000  cubic  yards, 
or  an  average  yield  of  1  •  9  dwts.  per  cubic  yard.  The  Cabinet  placers 
are  situated  on  the  tributaries  of  the  lower  portion  of  the  Chilka 
(Geltuga,  Kara,  &c.)  ;  between  the  Chilka  and  Unda  (Kazakova, 
Novo-Troi'tzk,  Uralguinski,  &c.)  ;  and  in  the  neighbourhood  of 
Nerchinsky-Zavod  (Burza,  &c).  Poorer  placers  belonging  to  the 
Crown  are  worked  by  private  individuals  on  the  lower  Geltuga.  The 
tenor  of  these  is  not  more  than  18  grains  to  the  cubic  yard.  Those 
worked  by  and  in  the  possession  of  private  individuals  carry  even  lower 
values  (12  to  15  grains  per  cubic  yard).  The  more  important  of  the 
private  mines  are  the  Malomalski  placer  on  the  Bystra.  where  the 
pay-streak  lies  under  25  feet  of  cover  ;  the  Chakhtaminsk  placer, 
a  little  further  west  ;  and  the  placers  of  the  Onon  river,  immediately 
north  of  the  Mongolian  frontier.  All  the  placers  are  geologically 
of  recent  origin,  and  have  but  little  cover.  The  source  of  the  gold 
is  known  for  the  Onon  and  Ilia  deposits,  where  the  gold  descends 
from  a  granite  massif  in  old  schists  and  slates.  Working  costs  are 
low  in  Transbaikalia,  since  labour  is  cheap  and  abundant.  Chinese 
workmen  will  attack  favourably  situated  gravels  containing  no  more 
than  5  to  6  grains  per  cubic  yard.a 

Yakutsk  (Lena). — The  auriferous  portion  of  the  great  Yakutsk 
province  of  Siberia,  lies  in  its  south-western  corner,  in  the  Lena 
district,  and  north-east  of  Lake  Baikal.  The  principal  deposits  are 
grouped  along  both  slopes  of  the  Krapotkin  mountains,  which  rise 
to  a  height  of  3,000  to  4,000  feet.  The  auriferous  gravels  occur  in  the 
valleys  of  the  head-waters  of  the  Patom  and  Yonya  rivers  flowing 
north,  and  in  the  Bodaibo  and  other  streams  flowing  south  to  the 
Vitim  river.  They  are  evidently  a  northward  continuation  of  the 
Transbaikalian  auriferous  belt.  Work  was  commenced  on  the 
Olekma  and  Vitim  placers  about  fifty  years  ago,  gold  being  first  dis- 
covered by  Tungouse  hunters.  The  placers  were  rapidly  developed, 
but,  as  the  following  table,  giving  the  yield  at  five-year  intervals, 
will  show,  appear  to  be  declining  in  importance  under  existing 
Siberian  methods  : — 


Year. 

Ounces. 

Year. 

Ounces. 

1850 

96 

1877 

488,680 

1852 

16,075 

1882 

394,802 

1857 

80,375 

1887 

241,125 

1862 

105,740 

1892 

345,281 

1867 

141,460 

1897 

310,247 

1872 

331,788 

The  annual  yield  during  the  last  years  of  the  century  would 
therefore  appear  to  have  been  worth  about  one  and  a  quarter  millions 
sterling.     This  is  largely  the  produce  of  a  few  great    companies. 

a  Glasser,  loc.  cit.,  p.  35. 


SIBERIA.  221 

The  Ivanovski  (Vitim)  and  the  Lena  companies  furnished  each 
about  £250,000  ;  the  Prokopeiovski  (Bodaibo)  about  £150,000,  &c. 
The  last-mentioned  mine  from  1890  to  1900  inclusive  produced 
£1,875,000  gold.  For  the  whole  region,  from  1897  to  1900  inclusive, 
there  were  treated  4,360,000  cubic  yards  sand,  yielding  approxi- 
mately £4,480,000,  or  a  little  more  than  5  dwts.  per  cubic  yard."  The 
bulk  of  this  came  from  the  Bodaibo  stream.  The  alluvium  is  per- 
petually frozen,  and  no  more  than  a  hundred  working  days  in  the 
season  may  be  anticipated.^ 

The  rocks  of  the  region  are  schists  and  gneiss,  with  quartzites 
and  minor  exposures  of  syenite,  aplite,  kersantite,  and  ,  diorite. 
They  are  traversed  by  white  lenticular  veins  of  barren^  quartz, 
which  nevertheless  sometimes  contain  crystals  of  galena  or  pyrite, 
in  which  case  the  latter  may  contain  a  little  gold.  Further  up  the 
Vitim  than  the  rich  placers,  and  near  the  Orlofka  river,  gold-quartz 
veins  are  known  at  the  Tagarak  (Kamen)  mine,  where  the  gold 
occurs  as  scales  in  the  quartz.  Still  higher  up  in  the  Vitimkhane, 
north-east  of  Barguzinsk,  thin  quartz  veins  carrying  gold  occur 
in  schists. 

To  return,  however,  to  the  Olekma- Vitim  placers,  these  are  of 
two  ages.  Pleistocene  and  Recent.  The  latter  lie  in  the  beds  of  the 
existing  rivers,  and  are  of  little  importance.  The  former  lie  buried 
beneath  frozen  alluvium  of  an  extraordinary  depth.  It  is  never  less 
than  65  feet,  and  may  reach  300  feet.  It  is  made  up  of  successive 
beds  of  clay,  mud,  and  sand.  The  pay-streak  is  on  bed-rock,  and 
is  from  2h  to  5  feet  thick.  It  is  generally  a  clayey  sand,  with  flat 
angular  pebbles,  of  many  rocks,  but  principally  of  schist.  The  gold 
tenor  may  vary  suddenly,  in  any  given  placer,  from  4  dwts.  to  If 
ounces  per  cubic  yard.  The  gold  of  these  ancient  deposits  is  rough, 
coarse,  and  crystallized  (octahedra  and  cubes),  while  that  of  the 
recent  gravels  is  fine  and  flaky.  Nuggets  weighing  26  dwts.  have 
been  found  in  the  Tikhona-Zadonsky  placer.  Both  pyrite  and 
pseudomorphs  of  limonite  after  pyrite  are  common  in  the  drift. 

A  remarkable  light  on  the  origin  of  the  alluvial  gold  has  been 
furnished  by  the  researches  of  Sementchenko  and  others.  In  the 
Nijni  placer  the  Lena  Company  separated  the  pay-streak  as  far  as 
possible  into  its  component  parts,  obtaining  : — 

60  -9  per  cent,  sand,  pebbles,  &c, 

32-6   per  cent,   clay  and    mud,  yielding  19-3  dwts.  of  gold  per 
cubic  yard, 
5  •  4  per  cent,  heavy  sand, 
1  -09  percent,  pyrites,  yielding  nearly  14  ounces  gold  per  cubic  yard. 

a  Purington,  Min.  Jour.,  April  20,  1907. 

h  Glasser,  Ann.  des  Mines,  Ser.  IX,  1900,  XVIII,  p.  18. 


222  ASIA. 

while  the  total  loss  in  separation  and  remaining  in  pyrites  was 
9|  dwts.  per  cubic  yard."  Sementchenko  has  separated  and  assayed 
the  pyrites  with  equally  remarkable  results.  From  the  Konstanti- 
novsky  placer  the  pyrites  residues  yielded  50- 9  ounces  (1,582  grammes) 
gold  per  metric  ton5;  from  the  Kruto'i  placer  10-7  ounces  (332-87 
grammes)  per  metric  ton.c  A  further  trial  on  the  pyrites  of  the 
Tikhono-Zadonsky  placer  gave  the  same  investigator: — ,l 

By  cyanide  .  .  9  ounces  per  metric  ton. 

By  fire  after  cyaniding     .  .    23  •  7         „  ,, 

By  fire  of  the  whole  . .   31  •  6 

Further  analysis  of  the  bullion  thus  obtained  showed  that  it 
was  only  758  fine  in  gold,  the  remainder  being  silver,  while  alluvial 
gold  from  the  same  placers  from  which  the  pyrites  was  gathered 
is  on  an  average  918  fine.  Obrutchev  and  Guerrassimov  have 
therefore  concluded  that  much  of  the  Vitim  and  Olekma  gold  has 
been  derived  not  from  gold-quartz  veins,  but  from  the  pyrites  in 
the  schists. 

Amur  (Amurskaia). — The  deposits  of  this  province  are  to  be 
found  almost  entirely  in  the  valleys  of  three  tributaries  of  the  Amur  : 
the  Zeiia,  Avhich  flows  into  the  Amur  at  Blagovieschensk  ;  the  Bureiia, 
meeting  the  Amur  a  little  further  down  stream,  and  flowing  from 
the  same  direction  as  the  Zei'a  ;  and  the  Urmi,  which  meets  the 
main  river  at  Khabarovsk.  The  last  are  often  known  as  the  Maliy- 
Khigan,  from  the  mountains  in  which  they  lie.  The  following  returns 
for  1897  illustrate  the  then  relative  richness  of  the  Amur  gold- 
fields  : — 


Zei'a  Basin       

Bureia  Basin 

Maliy-Khigan  Basin 
Head-waters  of  the  Amur 


Ounces.  Kg. 


148,093 

4,625 

26,845 

835 

16,139 

502 

8,616 

268 

The  basin  of  the  Zei'a  is  therefore  by  far  the  most  important. 
Its  principal  auriferous  affluents  are  the  Gilyui  and  the  Brianta, 
the  latter  having  as  tributaries  the  Djolon,  Ilikhan,  and  Unakha. 
The  first  deposits  known  (in  1867)  in  this  region  were  those  of  the 
Djalinda,  at  the  head  of  the  Ur,  a  tributary  of  the  Zei'a,  and  also 
those  of  the  Oldoi,  in  the  immediate  neighbourhood  of  the  preceding. 
Both  these  lie  to  the  north  of  Reinova  on  the  Amur.     Their  annual 


"  Guerrassimov,  Com.  Geol.  Russ.,  1904,  p.  81,  Lena. 

h  Loc.  cit,,  1901,  p.  29,  Lena. 

r\h.,  1904,  p.  81. 

^  Loc.  cit.  sup.,  p.  238. 


SIBERIA.  223 

yield  was  at  first  about  97,500  ounces  gold.  The  now  more  impor- 
tant placers  on  Gilyui  and  Brianta  rivers  were  discovered  about  1870, 
and  their  exploration  dates  from  1875.  The  working  season  is  here 
slightly  longer  than  on  the  Lena  tributaries,  averaging  from  100  to 
120  days/' 

The  rocks  of  the  Zei'a  district  are  gneiss,  amphibolitic  schists, 
(accompanied  often  by  eclogite)  and  granite,  together  with  Jurassic 
and  Pleistocene  deposits.  Gold  has  been  found  in  lenticular 
veinlets,  both  in  the  gneiss  and  in  the  schists,  and  it  has  further 
been  observed  that  those  in  the  amphibolite  schists  are  richer  than 
those  in  other  members  of  the  complex.6  According,  to  Ivanov/ 
however,  the  veins  in  the  gneiss  are  pegmatitic,  containing  also  mica 
and  felspar.  They  may  therefore  be  compared  with  the  alaskite 
veins  or  dykes  of  Spurr  from  the  not  greatly  dissimilar  auriferous 
region  of  Alaska.  The  gold  of  the  Jazonof  Klad  and  Dojdlivoi' 
placers  on  the  Unakha,  and  of  the  Troitzki,  on  the  Murzinski,  is 
derived  exclusively,  according  to  Yavorovsky  ,d  from  these  pegmatitic 
veins. 

The  placers  of  the  Amur  region  are  not  deeply  buried, 
as  on  the  Lena.  They  are  often  less  than  a  yard  thick,  and 
are  covered  by  14  to  21  feet  of  clayey  sand.  The  cover  rarefy  reaches 
35  feet  in  thickness.  Some  of  the  pay-streaks  have  been  very  rich. 
The  Leonovski  placer  on  the  Djolon  produced  in  two  years  (1889- 
90)  73,945  ounces  gold  from  140,800  cubic  yards,  a  yield  of  10J 
dwts.  per  cubic  yard.  During  fourteen  years  of  work,  the  tenor  of 
the  wash  treated  at  this  placer  has  been  3|  dwts.  per  metric  ton,  and 
no  less  than  401,875  ounces  have  been  recovered.  Terrace  deposits 
and  lacustrine  deposits  (as  high  as  400  feet  above  the  present  valley 
level)  occur  in  addition  to  the  recent  valley  placers.  The  Burei'a 
placers  lie  in  the  upper  valleys  of  the  Niman,  on  the  opposite  side 
of  the  mountains  from  those  of  Amgun  (Primorskoi  Province). 
Their  characters  agree  with  those  already  described  for  the  Zei'a. 
The  deposits  of  the  Mah'y-Khigan  are  at  the  head  of  the  Urmi, 
north-north-west  of  Khabarovsk.  They  are  numerous,  but  are 
neither  extensive  nor  rich.e 

Primorskoi  (Maritime  Province). — This  province,  as  its 
name,  both  in  Russian  and  in  English,  indicates,  lies  along  the 
Pacific  sea-board.     In  the  south  of  the  province  near  Vladivostock 

a  Glasser,  Ann.  des  Mines,  XVTII,  Ser.  IX,  1900,  p.  21. 

"  Yavorovsky,  Com.  Geol.  Russ.,  1900,  p.  48,  Amur. 

c  lb.,  p.  90. 

d  lb.,  1901,  p.  26. 

e  For  a  full  description  of  the  Amur  placers  consult  Yavorovsky,  St.  Petersb.  Min. 
Soc,  XXXIII,  Ser.  II,  1896,  p.  305 ;  and  Levat,  "  L'or  en  Siberie  Orientale," 
Paris,  1897,  vol.  II. 


224  ASIA. 

are  several  auriferous  occurrences.  On  the  island  of  Askold,  37 
miles  east  of  Vladivostock,  a  gold-quartz  lode  lies  between 
quartzites  and  crystalline  rocks.  The  lode  is  composed  of  several 
very  thin,  generally  parallel,  veinlets.  Normally,  there  are  two 
main  veinlets,  1  to  4  inches  wide  and  12  inches  apart.  The  average 
tenor  is  33  dwts.  per  ton  in  a  shoot  from  130  to  160  feet  long.  Beyond 
the  shoot  the  tenor  falls  to  a  little  under  an  ounce  for  nearly  500 
feet.  In  depth  the  veinlets  appear  to  weaken.  To  1902  £32,000  gold 
had  been  extracted  from  the  mine.a  Another  auriferous  vein  has 
been  worked  at  Nakhoda,  25  miles  east  of  Askold  Island,  and  on  the 
mainland.  Auriferous  placers  occur  a  little  distance  both  to  the 
east  and  west  of  Vladivostock  ;  west  of  Lake  Khapka,  and  along  the 
Imani  river,  but  all  are  of  little  present  importance. 

The  placer  deposits  of  the  northern  portion  of  the  Primorsko'i 
province  are,  on  the  other  hand,  of  considerable  value.  The 
richest  are  on  the  head-waters  of  tributaries  of  the  Amgun,  which 
joins  the  Amur  very  near  Nikolaevsk  and  the  sea.  These  were 
first  worked  in  1872,  but  then  yielded  little.  Towards  1891,  richer 
beds  were  found,  especially  on  the  Semi,  Kerbi,  and  Nimelien  tribu- 
taries, and  for  a  few  years  the  annual  output  was  some  64,000 
ounces.  From  1891  to  1904  the  Amgun  region  produced  739,450 
ounces  (23,000  kg.)  gold.  Other  alluvial  placers  occur  near  Lakes 
Orel  and  Tchlia,  to  the  north-west  of  Nikolaevsk. 

The  Kerbi,  Nilaw,  and  Semi,  with  their  various  tributaries 
having  their  sources  in  the  Lesser  Chingan  mountains,  form 
the  Upper  Amgun  auriferous  region.  Their  areas  of  erosion, 
unlike  those  of  the  other  rivers  of  the  Amgun  system,  which  flow 
through  granite  hills,  are  exclusively  in  crystalline  schists  and 
phyllites.  In  the  Semi  valley  itself  the  length  of  the  workable 
deposit  is  6 J  miles,  while  in  its  tributary  streams  5-9  miles  are 
available.  In  the  richest  part  (Rozhdestvensky)  of  the  valley, 
the  auriferous  gravels  have  a  total  width  of  nearly  half  a  mile,  with 
a  workable  width  of  a  quarter  of  a  mile.  The  overburden  (torf)  is 
about  13  feet,  and  the  pay-gravel  (plast)  from  5  to  7  feet  in  thickness. 
In  many  places,  however,  and  especially  in  the  smaller  valleys, 
gold  is  found  in  fairly  large  grains  directly  under  the  surface  soil. 
The  tenor  of  the  pay-gravel  is  extremely  variable.  It  may  vary  in 
small  patches  up  to  one  and  even  to  3  ounces  per  cubic  yard,  but  the 
average  yield  of  the  gravels  hitherto  washed  has  been  from  H  to  8 
dwts.  (2-6  to  12  •  7  grams.)  gold  per  metric  ton.  The  gravel  Avashed 
during  1906  had  a  tenor  of  1  to  1 J  dwts.  (1-9  to  1-6 grams.)  gold 
per  metric  ton.  Nuggets  weighing  from  h  dwt.  to  3  dwts.  are 
numerous,  and  they  are  occasionally  found  up  to  3  ounces  in  weight . 

a  Bordeaux;,  Ann.  des  Mines,  II,  Ser.  X,  1902,  p.  544. 


SIBERIA.  225 

The  largest  found  weighed  nearly  26  ounces.  The  gold  found  is  often 
crystallized,  with  sharp,  well-defined  edges.  Its  fineness  varies  from 
910  to  952."  All  the  Primorskoi  placers  hitherto  discovered 
have  been  Pleistocene  in  age.  They  appear  to  have  derived 
their  gold   from  gneisses  and  crystalline  schists. 

Scattered  auriferous  deposits  occur  further  north,  along  the 
shores  of  the  Sea  of  Okhotsk  south-west  of  Port  Ayan  ;  at  Okhotyek  ; 
and  at  the  base  of  the  Taigonoskai'a  Peninsula.  Gold  also  occurs  in 
limited  quantities  in  Kamchatka  itself  (Lat.  55°  N.  and  Long. 
127°  E.).  Bogdanovitch  and  Lemiakin  found  auriferous  gravels  near 
Ayan  on  the  banks  of  the  Aikaschra  river.  These  were  made  up 
of  the  debris  of  volcanic  rocks  and  carried  nuggets  of  fine  gold.^ 

Recent  explorations,  instigated  by  the  discovery  of  the  extremely 
rich  placer  deposits  of  the  neighbouring  Seward  Peninsula  in  Alaska, 
have  led  to  the  discovery  of  auriferous  alluvial  gravels  near  Cape 
Deshneff  (East  Cape)  on  the  Chukchi  Peninsula,  the  most  easterly 
land  projection  of  Asia.  They  occur  on  the  Thunilthan  river,  not  far 
from  its  mouth,  and  a  few  miles  south-west  of  Cape  Deshneff. 
The  bed-rock  is  metamorphic,  mainly  mica-schist  and  clay-schist. 
The  gravels  are  not  very  rich,  averaging  perhaps  only  6  grains  per 
metric  ton.  Their  value  is  therefore,  to  judge  from  present  informa- 
tion, inconsiderable.0 


ASIA  MINOR. 

Numerous  small  veins  of  auriferous  mispickel  are  found  in 
western  Asia  Minor,  especially  in  the  neighbourhood  of  Mount  Tmolos, 
on  the  northern  slopes  of  which,  near  Sardis,  were  the  streams  of 
the  golden  Pactolus  of  the  Greek  historians.  Their  sands  are 
reputed  to  have  furnished  the  wealth  of  Croesus,  but  their 
gold  content,  probably  never  great,  despite  the  stories  of  the 
ancient  writers,  was  exhausted  long  before  the  Christian  era.  The 
strongest  mispickel  vein  observed  in  this  neighbourhood  was  of 
low-grade  quartz  15  feet  wide,  but  the  majority  are  smaller 
and  richer.  The  gold  content  varied  from  a  trace  to  a  little  over 
three  ounces,  but  none  of  the  richer  veins  were  sufficiently  large  or 
permanent  to  warrant  working.^ 

North  of  the  Bay  of  Smyrna,  and  in  the  neighbourhood  of  the 
Dardanelles,  extensive  ancient  workings  have  been  discovered. 
Those  at  Serdjiller,    12  miles    from  the    Dardanelles,    correspond 

a  Maier,  Zeit.  fur  prakt.  Geol.,  XIV,  1906,  p.  101. 

b  Zeit.  fiir  prakt.  Geol.,  IV,  1896,  p.  456. 

c  Korsuchin,  Zeit.  fiir  prakt,  Geol,  XIV,  1906,  p.  380. 

d  Thorns,  Trans.  Amer.  Inst.  M.E.,  XXVIII,  1898,  p.  216. 


226  asia. 

4 

fairly  closely  with  the  site  of  the  ancient  Astyra.  The  country  of  the 
old  workings  is  mica-schist  overlain  and  intruded  by  Lower  Tertiary 
igneous  rocks.  These  latter  were  termed  "trachyte  "  by  Tchihatchef 
(1867),  but  have  been  referred  by  Diller, °  English,  and  Elett,& 
to  liparites,  mica-  and  hornblende-andesites,  augite-andesite, 
and  basalt.  The  andesites  were  usually  much  decomposed. 
There  would  thus  appear  to  be  some  analogy,  and  indeed 
a  possible  genetic  connection  between  this  auriferous  area 
and     those    of     Transylvania    and    of     Eastern    Servia.  The 

quartz  veinlets  in  the  volcanic  rocks  carry  argentiferous  galena, 
blende,  pyrite,  chalcopyrite,  stibnite,  and  a  little  free  gold.  The 
gold  content  is,  however,  very  low.  The  mines  north  of  Smyrna 
were  opened  up  by  an  English  company  in  1900,  but  though  a  con- 
siderable sum  was  spent  no  gold  was  obtained. 

The  only  important  gold  mines  in  Asia  Minor  are  those  of 
Bulgar  Ma'aden  in  the  Boulgar  Dagh  mountains.  (Long. 
32°  20'  E. ;  Lat.  37°  25'  N.)  Their  rocks  appear  from  Tchi- 
hatchef 's  map  (1867)  to  be  Lower  Tertiary  sedimentaries,  with 
dolerite  in  the  vicinity.  The  veins  are  galeniferous,  yielding  21  per 
cent,  of  lead.  The  smelted  lead  may  carry  as  much  as  296  ounces 
silver  and  2|  ounces  gold  per  ton.  The  yield  of  the  mines  for  1901 
was  401  tons  litharge,  263,983  ounces  silver,  and  343  ounces  gold.c 
These  mines  are  worked  under  a  Turkish  iracle  of  1 821  by  the  peasants, 
but  are  nevertheless  the  property  of  the  Crown.  The  buying  of  the 
produce  is  a  Government  monopoly,  the  Government  giving 
12|  piastres  (2s.  7d.)  for  each  dirhem  (2  dwts.)  of  gold  (?).rf 

South  of  Trebizond,  at  Gumesh-Khana  (Long.  39°  25'  E.  ;  Lat. 
40°  30'  N.)  are  auriferous  silver  mines,  apparently  associated  with 
igneous  rocks.  Alluvial  gold  occurs  in  the  Dumludagh  range,  north 
of  Erzeroum  (a  diorite  area  on  Tchihatchef 's  map). 


ARABIA. 

No  gold  mines  are  known  to  exist  in  Arabia.  The  only  available 
information  is  a  statement  of  Capt.  Burton  that  gold  is  to  be  found 
near  Muwaylah  in  the  Hejaz  district.6 

°  Q.J.G.S.,  XXXIX,  1883,  p.  627. 

b  lb.,  LX,  1904,  pp.  254-276. 

c  Simmersback,  Zeit.  Berg-Hiitten  und  Sal.  Wesen,  LII,  1904,  p.  540. 

d  Wylie,  Cons.  Rep.,  1907. 

e  Burton,  "  The  Gold  Mines  of  Midian,"  London,  1878. 


227 

PERSIA. 

Persia  also  appears  to  be  devoid  of  important  auriferous 
deposits.  In  1899  a  British  company  was  formed  to  work  the 
metalliferous  deposits  of  the  country.  Its  operations  resulted 
in  failure.  Old  gold  placers,  now  exhausted,  occur  between 
Nishapur  and  Meshed  in  the  Binalud  mountains.  The  copper  veins 
of  Far  Daod,  near  Bosmishk,  are  said  to  have  yielded  7  dwts.  gold 
per  ton/'  Gold  is  said  to  occur  in  the  granite  and  crystalline  schist 
of  the  Elwund  mountain,  near  Hamadan  (the  ancient  Ecbatana) ;  in 
the  vicinity  of  Teheran  and  Shah  Abdul  Azim  ;  and  near  Galugo.^ 
Veins  in  mica-schist  were  formerly  worked  near  Meshed  in  the 
Binalud  mountains.  Ancient  gold  washings  are  reported  from 
Kawend,  west  of  Zengan  and  south-west  of  Reshd.c 


BALUCHISTAN. 

Gold  is  absent  from  Baluchistan,  so  far  as  is  known  at  present. 
In  Seistan,  to  the  north  of  Baluchistan  proper,  and  towards  the 
south-west  corner  of  Afghanistan,  gold  may  possibly  occur,  for  old 
Mahommedan  records,  in  other  respects  fairly  accurate,  relate  that 
a  vein  of  gold  was  found  there  in  998  a.d.,  and  was  worked  until  the 
reign  of  Musaud  (1031-1042  a.d.),  when  it  was  destroyed  by  an 
earthquake.^ 


AFGHANISTAN. 

Gold,  both  vein  and  alluvial,  has  long  been  worked  in  Afghanis- 
tan. Gold-quartz  veins,  apparently  forming  a  stockwork,  occur 
three  miles  north  of  Kandahar  city.  They  traverse  a  zone 
of  contact  between  hippuritic  limestone  and  trap  (andesite  ?). 
The  country  is  greatly  decomposed,  so  much  so  that  it  is  impossible 
from  the  examination  of  the  specimens  collected  in  1880  and  now 
deposited  in  the  Calcutta  Museum,  to  determine  definitely  the 
original  nature  of  the  rock.  It  is  probably,  however,  to  be 
grouped  with  the  intrusive  Eocene  andesitic  or  dioritic  rocks  that 
occur  elsewhere  in  Afghanistan.  The  gold  is  coarse,  and  generally 
lies  in  vughs.e    An  immense  number  of  veinlets  run  through  the  rock, 

a  Hennecke,  Zeit.  fur  Berg-Hutt.  und  Sal.  Wesen,  XLVII,  1899,  p.  272. 

b  Tietze,  Jakrb.  Geol.  Reichanst.,  XXIX,  1879,  p.  648. 

cScliindler,  lb.,  XXXI,  1881,  pp.  171,  179,  188. 

*  Briggs,  "  Mahommedan  Power  in  India,"  I,  p.  33. 

e  Bellew,  "  From  the  Indus  to  the  Tigris,"  London,  1874,  pp.  137-140  ;    Griesbach, 
Memoirs  Geol.  Surv.  India,  XVIII,  1880,  p.  8G. 


228  asia. 

and  pieces  of  gold  as  large  as  an  almond  have  been  picked  out. 
The  mine  was  discovered  in  1860,  and  yielded  well  for  the  first  two 
or  three  years.  Later,  it  was  farmed  out  for  Rs.  5,000  (£500)  per 
annum.  The  annual  return  was  said  to  be  £1,000,  but  the  mine  was, 
nevertheless,  worked  only  at  intervals.  Work  ceased  when  the 
open-cast  pit  had  reached  a  depth  of  80  feet.  At  that  depth  the 
sides  fell  in  and  killed  the  workmen,  who  were  notoriously 
unskilled  miners. 

Alluvial  gold  is  reported  from  the  Hazara  country  ;  from  the 
neighbourhood  of  Istalif ,  about  20  miles  north  of  Kabul ;  and  from 
the  Kohistan  country  generally,  but  the  quantity  obtained  is 
probably  insignificant.  Deposits  analogous  to  those  already 
described  north  of  the  Panj  river,  in  Bokhara,  may  also  be 
reasonably  expected  to  occur  to  the  south  of  that  territorial 
boundary. 


TIBET." 

Tibet  is  the  only  one  of  the  world's  goldfields  now  remaining 
closed  to  modern  enterprise,  and  even  to  scientific  examination. 
The  vast  gold-bearing  area  of  south-western  Tibet  stretches  east- 
south-east  from  Rudok,  near  the  Ladakh  frontier,  towards  the 
Zilling  Cho,  with  an  indefinite  extension  towards  the  north,  but 
certainly  as  far  as  the  northern  slopes  of  the  Kuen-Lun  Mountains. 
No  mining  engineer  has  seen  its  workings,  no  geologist  has  examined 
its  rocks.  The  following  is  believed  to  comprise  the  sum  of  our 
available  information  on  the  gold  deposits  of  the  region. 

The  earliest  positive  reference  to  Tibetan  gold  is  contained  in  the 
'  Kitabu-1-Akhbar  "  of  'Ubaidu-1-lah  {circa  900  a.d.).  He  quotes 
the  old  tradition  of  the  invasion  of  Tibbat  (Tibet)  by  the  Hamiri 
rulers  of  Yemen  in  Arabia.  One  Sabit,  their  viceroy,  was  incited 
thereto  by  the  following  passage  from  a  letter  describing  the  country 
of  Tibbat  :  "  One  of  the  Tubba'yawa  (the  rulers  of  Yemen)  set  out 
towards  the  east,  and  used  great  efforts  until  he  reached  a  country, 
the  verdure  of  which  was  gold,  and  its  earth  musk,  and  its  herbage 
incense,  its  game  the  musk  deer,  its  mountains  snow,  and  its  plains 
most  pleasant."  Needless  to  say,  Sabit  went,  and,  according  to  the 
chronicle,  found  that  it  was  so. 

The  first  European  traveller  to  Central  Asia  of  whose  journey 
a  record  has  been  preserved,  was  William  de  Rubruquis,  a  Fleming 
born  near  Brussels,  who  was  sent  in  1253  a.d.  on  a  Papal  mission 
to  the  Tartars.  He  was  himself  never  nearer  Tibet  than  Karakoram, 
but  mentions  having  at  that  place  met  one  William  Bourchier,  a 

"  Maclaren,  Min.  Jour.,  LXXI,  1907,  p.  826. 


TIBET.  229 

Parisian  goldsmith,  who  had  resided  for  some  time  in  Tibet  at  the 
gold  mines  of  "  Bocol."  It  is  probable,  as  Sandberg  suggests,  that 
"Bocol"  is  identical  with  Bokalik  (Long.  91°  E.,  Lat.  36°  28'  N,), 
where  both  Carey  and  Bonvalot  report  gold  diggings.  Seventy-three 
years  later  Lhasa  itself  was  visited  by  Friar  Odoric  of  Pordenone. 
In  his  narrative,  which  was  dictated  in  Padua  in  1330  a.d.,  and 
which,  together  with  that  of  Rubruquis,  supplied  the  compiler  of 
"  The  Travels  of  Sir  John  Mandeville  "  with  much  of  his  material, 
there  is  no  mention  of  gold  in  Tibet,  but  as  the  friar's  route  from 
China  did  not  pass  by  any  goldfields  now  known,  the  omission 
has  no  great  significance.  The  famous  Marco  Polo  was  never  in 
Tibet  itself,  but  travelled  both  to  the  north  in  Chinese  Turkestan, 
and  to  the  east  and  south-east  in  China,  and  merely  reports  the 
existence  of  gold  in  Tibetan  territory. 

We  turn  again  to  a  Mussulman  chronicle,  the  "  Tarikh-i- 
Rashidi  "  of  the  Mirza  (Prince)  Muhammed  Haidar,  a  viceroy  of 
Tashkend,  who,  proclaiming  a,  jehad,  led,  about  1530,  an  expedition 
into  Tibet.  Haidar's  avowed  object  was  to  burn  and  utterly 
destroy  Usang  or  Ursang  (Lhasa),  a  seat  of  infidel  error,  and  so  an 
accursed  object  in  the  sight  of  all  true  believers.  He  failed  signally, 
defeated  by  the  Arctic  rigour  of  the  country,  and,  with  a  few  fol- 
lowers, finally  escaped  with  difficulty.  His  chronicle  is  somewhat 
discursive,  but  the  words  of  the  translator"  are  here  quoted  : 
"  Among  the  astonishing  things  of  Tibbat,  one  is  the  gold  mines. 
In  most  places  frequented  by  the  Canbahs  (the  nomads  of  Tibet) 
there  are  gold  mines  ;  indeed,  in  most  of  the  Tibbat  territory  there 
is  gold.  Among  these  are  two  wonderful  mines.  One  is  in  what  is 
called  Altun-ei-Tibbat  (golden  Tibet  ?)  by  the  Mughals,  in  which 
some  septs  of  the  Dolbah  Canbahs,  or  nomads,  work,  but  on  account 
of  the  excessive  coldness  of  the  air  they  are  not  able  to  work  more 
than  forty  days  in  each  year.  The  shafts  open  on  level  ground  in 
such  wise  that  a  person  can  enter  thein  ;  they  are  numerous,  and 
most  of  them  lead  one  into  the  other.  It  is  affirmed  that  as  many 
as  three  hundred  families  at  a  time  continue  at  all  times  to  dwell  in 
these  shafts  or  holes.  ...  In  them,  likewise,  they  do  not  burn 
any  oil,  only  clarified  fat  of  sheep,  in  which  no  tallow  is  contained. 
They  bring  the  earth  in  sieves  to  the  mouths  of  the  shafts,  and  wash 
it,  and  it  is  said  that  from  one  sieveful  of  earth  as  much  as  ten  misqals 
on  an  average  are  produced."  The  modern  Persian  misqal  weighs 
approximately  4-6  ounces,  so  that  either  an  ancient  misqal  or 
one  of  another  locality  weighing  much  less  was  used.  Raverty 
estimates  the  misqal  at  1-|-  drams,  and  this,  again,  may  be  either 
41    grains    or    90    grains,    according    to    whether    avoirdupois    or 

a  Raverty,  Jour.  As.  Soc.  Beng.,  LXIV,  1895,  p.  92. 


230  .ASIA. 

apothecaries'  weights  are  indicated.  The  Mirza  goes  on  to  describe 
the  methods  :  "  The  same  person  digs  out  the  earth,  brings  it  out, 
and  washes  it  himself  ;  and  in  the  course  of  a  day  can  fill  and  wash 
twenty  sievesful.  Although  this  matter  has  not  been  verified  and 
tested  by  me,  nevertheless  the  statement  agrees  in  every  way  with 
the  reports  current  in  Tibbat,  and  therefore  it  has  been  recorded 
here.  Another  territory  is  Kokah,  which  contains  some  two 
hundred  forts.  Its  length  is  three  days'  journey  ;  and  there  is 
gold  to  be  found  in  every  part  of  it.  They  dig  out  a  certain  quantity 
of  earth,  and  spread  it  out  on  the  face  of  a  cured  hide,  and  pick  out 
the  gold  therefrom,  which  is  in  grains.  Some  of  these  grains  are  of 
the  size  of  lentils  or  peas,  and  it  is  said  that  nuggets  sometimes  of 
the  size  of  an  egg  and  even  of  the  size  of  a  sheep's  liver,  or  even 
larger,  are  found." 

We  have,  indeed,  in  the  "  Tabaqat-i-Nasiri  "  a  reference  to  a 
very  large  nugget.  Among  the  presents  sent  to  the  Sultan  Mahom- 
med  by  Genghis  Khan  was  a  nugget  of  pure  gold  "as  big  as  a  camel's 
neck,  which  had  been  brought  from  the  mountain  range  of  Tamghaz, 
so  that  it  was  necessary  to  convey  that  piece  of  gold  upon  a  cart." 
Tamghaz  is  possibly  the  Kuen-Lun  mountain  range.  To  resume  the 
Mirza's  narrative  :  "  At  the  time  that  I,  the  writer  of  these  pages, 
fixed  a  capitation  tax  on  the  Kokah  chiefs,  they  related  that  only  a 
short  time  before,  a  labourer  was  excavating  in  a  certain  part  when 
the  implement  he  was  using  became  so  firmly  fixed  in  a  place  that 
with  all  his  efforts  he  was  unable  to  withdraw  it  again.  He  removed 
the  earth  from  around,  and  what  does  he  behold  but  a  large  stone, 
and  embedded  in  the  middle  of  it  was  gold,  and  the  spade  firmly 
fixed  therein.  Leaving  it  just  as  it  was,  lie  went  away,  and  informed 
the  Hakim,  or  Governor,  of  the  matter,  when  that  functionary  and 
those  then  present  with  him  went  in  a  body  to  the  spot,  and  took  hold 
of  the  mass,  broke  the  stone,  and  1,500  misqals  of  pure  Tibbati  gold 
were  extracted  from  it,  each  misqal  of  that  part  being  a  misqal  and 
a  half  of  the  usual  weight.  The  gold  of  Kokah  which  they  extract 
from  the  earth  is,  indeed,  so  pure  that  however  much  it  may  be 
assayed  and  tested,  the  only  loss  which  arises  is  that  of  the  right  of 
the  fire  (i.e.,  what  is  lost  in  treating  and  melting)  ;  and  this  fact  is 
considered  astonishing  and  wonderful  by  travellers  and  gold- 
smiths, and  probably  nowhere  else  in  the  world  can  such  a  thing  be 
pointed  out." 

In  1665,  Francois  Bernier,  who  was  then  in  Kashmir  in  atten- 
dance on  the  Emperor  Aurungzebe,  relates  in  letters  to  Paris  a 
conversation  with  the  ruler  of  the  countries  now  known  as  Ladakh 
and  Little  Tibet.  "  I  heard  him  say  that  his  countrv  on  the  east  did 
confine  with  great  Tibet  ;  that  it  was  30  or  40  leagues  broad  ;  that 
there  was,  indeed,  some  little  crystal  musk,  and  wool,  but  for  the 


TIBET.  231 

rest  very  poor,  and  that  there  were  no  gold  mines  as  was  said  " — 
a  most  politic  statement  when  made  to  a  Mughal  Emperor.  To 
Bernier's  fellow-countryman,  Jean  Baptiste  Tavernier,  the  tattling 
jewel  merchant,  we  are  indebted  for  much  of  our  information  con- 
cerning the  India  of  the  seventeenth  century ;  but  he  merely 
records  the  rumour  of  gold  in  Tibet,  incidentally,  however,  drawing 
a  picture  which  must  have  tantalised  his  fellow  jewel  merchants 
in  Paris.  "  Toward  the  Thibet,  which  is  the  ancient  Caucasus, 
in  the  territories  of  a  Raja,  beyond  the  kingdom  of  Cachemir,  there 
are  three  mountains,  close  by  one  another,  one  of  which  produces 
excellent  Gold,  the  other  Granats,  and  the  third  Lapis-Lazuli." 

The  Jesuit  fathers  Grueber  and  d'Orville,  who  spent  two 
months  inLhassa  in  1662,  are  as  silent  asOdoric  concerning  Tibetan 
gold,  as  also  are  two  members  of  the  same  order,  Ippolito  Desideri 
and  the  Eurasian,  Freyre,  who  resided  in  Lhassa  from  1716  to  1729. 
The  letters  of  the  fiery  and  unfortunate  Francisco  Orazio  della 
Penna,  the  chief  of  the  Capuchin  Order  in  Lhassa  during  their  long 
sojourn  (1716-1780)  in  that  place,  contain  the  earliest  definite  infor- 
mation we  possess.  "  There  are  many  goldfields  in  the  provinces  of 
U,  Tzang,  Tang,  Khakpo,  Khombo,  and  Kham,  and  silver  (as  far  as 
is  known)  in  the  province  of  Kham." 

In  1774  George  Bogle  was  sent  by  Warren  Hastings  on  a 
mission  to  the  Teshu  Lama.  In  conversation  with  Tibetan  mer- 
chants concerning  the  products  of  the  country,  he  was  told  by  them 
that  "as  to  the  products  of  this  country,  people  imagined  from 
gold  being  produced  in  it  that  it  was  extremely  rich  ;  but  this  was 
not  the  case,  and  that  if  extraordinary  quantities  of  gold  were  sent 
to  Bengal,  the  Emperor  of  China,  who  was  sovereign  of  the  country, 
would  be  displeased  at  it."  On  the  death  of  the  Lama  in  Pekin  in 
1782,  Warren  Hastings,  with  characteristic  foresight,  sent  a  second 
embassy  to  Tibet,  in  this  case  under  Captain  Samuel  Turner.  The 
medical  officer  associated  with  him  was  Mr.  Sanders,  who  published 
mineralogical  and  other  notes  on  the  journey.  Of  gold  he  says  : 
"  They  find  it  in  large  quantities,  and  frequently  very  pure.  In  the 
form  of  gold  dust  it  is  found  in  the  beds  of  rivers,  and  at  their 
several  bendings,  generally  attached  to  small  pieces  of  stone,  with 
every  appearance  of  its  having  been  part  of  a  larger  mass.  They 
find  it  sometimes  in  large  masses,  lumps,  and  irregular  veins  ;  the 
adhering  stone  is  generally  flint  or  quartz,  and  I  have  sometimes 
seen  a  half -formed,  impure  sort  of  precious  stone  in  the  mass.  By 
a  common  process  for  the  purification  of  gold  I  extracted  12  per  cent, 
of  refuse  from  some  gold  dust  ;  and  on  examination  found  it  to  be 
sand  and  filings  of  iron,  which  last  was  not  likely  to  have  been  with 
it  in  its  native  state,  but  probably  employed  for  the  purpose  of 
adulteration."     Notwithstanding  this  most  circumstantial  account, 


232 


ASIA. 


it  is  quite  certain  that  Sanders  never  saw  a  Tibetan  goldfield,  and 
that  the  information  was  gained  from  the  Tibetans,  but  he  would, 
nevertheless,  have  abundant  opportunities  for  examination  of  gold 
dust,  which  was  then  the  only  form  of  currency  in  the  country. 

The  brothers  Strachey,  who  visited  the  sacred  Manasarowar 
lakes  in  1846  and  1848  respectively,  reported  old  gold  workings  in 
that  neighbourhood.  It  appeared  that  the  fields  to  the  north  were 
let  on  a  triennial  lease,  and  that  the  farmer  or  Sarpon  paid  for  the 
right  17,000  rupees  (£1,700)  to  the  Lhassa  treasury.  He  had  some 
170  miners  at  work,  but  the  country  in  which  the  mines  lay  was  so 
inhospitable  that  nearly  all  supplies  {satu,  ghiu,  and  tea)  were  sent 


8J7 
EASTERN 

TURKESTAN 


35-KASHMIR: 


hotan      .Nia         jKqpa""" 
Kina    •Sorqhak 

; '     ^705C 

-*     ;u     E 


,16360 


AkkaTaqh 


^■iPmzg^  X<?~ 


1    N    D    I   X 


Lithanq 

Sketch  Map 

of 

TIBET 

KnownGoIdfields . 


Fig.  89.     Sketch  Map  showing  position  of  Tibetan  Goldfielbs. 


from  Pruang  in  Hundes.  Occasionally  large  nuggets  were  found,  and 
the  Lama  of  Cangri  was  said  to  have  one  weighing  nearly  30  ounces. 
During  1865  and  1866  geographical  explorations  of  considerable 
value  were  carried  on  by  Pandit  Nain  Singh,  one  of  the  most  famous 
of  the  devoted  band  of  native  explorers  employed  by  the  Trigno- 
metrical  Survey  of  India  to  collect  information  regarding  those 
regions  into  which  a  European  could  not  penetrate  with  safety. 
Though  important  geographically,  the  explorations  during  these 
years  yield  little  information  for  our  present  purpose.  In  1867, 
however,  Nain  Singh,  together  with  his  brother,  who  had  previously 
been  somewhat  of  a  failure  as  an  explorer,  and  a  third  pandit,  set 
out  in  the  guise  of  Basahris  to  explore  the  country  along  the  eastern 
branch  of  the  Upper  Indus.  Soon  the  brother's  nerve  gave  way, 
and  he  returned  to  civilisation  and  safety.     The  third  pandit  went 


TIBET.  233 

up  the  Indus,  and  Nain  Singh  was  now  alone.  On  August  26th  of 
that  year,  after  a  most  arduous  march,  he  crossed  the  Chomorang-la 
(16,670  feet),  and  finally  reached  the  large  camp  of  Thok-Jalung 
(Long.  81°  37'  38",  Lat.  32°  24'  26-5"),  the  principal  goldfield  of  the 
country.  He  found  the  camp  situated  on  a  wide  desolate  plain,  of 
a  prevailing  reddish  brown  colour.  As  he  approached  it  his  ears 
were  gladdened  by  the  noise  of  a  great  number  of  voices  singing 
together,  and  on  his  arrival  found  that  the  sound  came 
from  the  gold-diggers  and  their  families.  The  goldfield  was 
quite  new,  and  had  been  worked  extensively  for  some  eight  or  nine 
years  only.  According  to  Nain  Singh  the  workings  consisted  of  a 
large  excavation  from  10  to  200  paces  in  width,  and  some  25  feet 
in  depth,  access  to  the  bottom  being  by  means  of  steps  and  slopes, 
the  earth  as  dug  out  being  thrown  up  on  either  side.  The  excava- 
tion was  about  a  mile  in  length.  The  digging  was  carried  on  with  a 
long-handled  shovel,  and  occasionally  with  an  iron  hoe.  A  very 
small  stream  runs  through  the  goldfield,  and  the  bottom  of  the 
excavation  was  consequently  rather  a  quagmire  during  the  day  time, 
but  the  stream  was  invaluable  for  washing.  The  waters  were 
dammed  back,  and  a  sloping  channel  left  for  the  escape  of  the  over- 
flow. A  cloth  (felt  ?)  was  spread  at  (along  ?)  the  bottom  of  the 
channel,  and  kept  down  by  a  number  of  stones,  forming  an 
uneven  bottom.  One  man  brought  earth  from  the  excavation, 
and  sprinkled  it  over  the  channel,  whilst  another  drove  water  down 
the  channel  by  means  of  a  leather  bag.  The  water  carried  the 
Jighter  soil  away,  but  the  pieces  of  gold  fell  into  the  uneven  places, 
and  were  easily  collected  in  the  cloth  by  lifting  up  the  stones.  The 
yield  of  gold  seems  to  be  large  and  the  finds  occasionally  very 
heavy.  The  pandit  saw  one  nugget  about  30  ounces  in  weight. 
The  diggers  say  that  they  can  recognise  the  auriferous  gravel  at 
once.  The  goldfields  are  carefully  watched  by  the  Lhassa  authorities 
and  are  superintended  by  a  sarpon  or  gold  commissioner.  The  tax 
levied  for  the  right  to  dig  is  one  sarShu,  or  about  1/5  ounces 
(16s.),  per  digger  per  annum. 

The  pandit  said  that  in  all  his  travels  he  never  experienced  such 
intense  cold  as  at  Thok-Jalung,  owing,  he  thought,  rather  to  the  high 
wind  that  was  always  blowing  than  to  the  great  elevation  (16,330 
feet).  During  the  winter  the  diggers  are  closely  wrapped  up  in  furs, 
and  without  them  would  perish.  Their  tents,  to  avoid  the  wind,  are 
always  pitched  in  pits  some  7  or  8  feet  below  the  surface  of  the 
ground.  Despite  the  cold,  the  diggers  prefer  working  in  the  winter, 
since  then  the  frozen  gravel  stands  well.  The  water  near  Thok- 
Jalung  is  so  brackish  that  it  cannot  be  drunk  until  it  has  been  frozen 
and  remelted.  Argols  (cattle  droppings)  are  the  only  fuel. 
A   year   after  Nain  Singh's  visit  the  third   pandit     travelled    to 


234  ASIA. 

Rudok,  and  from  thence  east  to  Thok-Jalung.  On  the  way 
he  heard  minute  descriptions  of  no  fewer  than  seven 
separate  goldfields — viz.,  those  of  Thok-Sarkong,  Thok-Dikla, 
Thok-Ragyok,  Thok-Thasang,  Thok-Maroobhoob,  Gunjee  Thok, 
and  Thok-Nainmo,  beside  those  of  Thok-Sarlung  (Charalung)  and 
Thok-Jalung,  which  he  visited.  Thok,  it  must  be  explained,  is  the 
Tibetan  for  gokmeld.  Thok-Sarlung  had  at  one  time  been  the 
chief  goldfield  of  the  district,  but  had  been  in  a  great  measure 
abandoned  on  the  discovery  of  Thok-Jalung.  At  the  former  place 
the  pandit  passed  a  great  excavation  30  to  40  feet  deep,  200  feet  wide, 
and  2  miles  in  length,  from  which  the  gold  had  been  extracted.  At 
first  sight  it  would  appear  that  this  description  could  fit  only  the 
open-cast  along  the  outcrop  of  a  vein,  but  it  is  probable  that  the 
dimensions  of  the  excavation  were  governed  by  the  water  available, 
and  that  the  long  excavation  represents  alluvial  ground  washed  on 
either  side  of  a  stream,  as  apparently  is  the  case  at  Thok-Jalung. 

Nain  Singh  in  a  later  journey  (1873)  reached  the  Thok-Daurakpa 
goldfields,  which  were  second  in  importance  only  to  those  of  Thok- 
Jalung.  The  Daurakpa  goldfields  are  15,280  feet  above  sea-level, 
and  the  diggers  dwell  in  caves  called  phukpa.  There  were  then 
thirty-two  of  these,  containing  each  from  five  to  twenty-five  indivi- 
duals. These  caves  are  selected  as  habitations  from  necessity 
rather  than  from  choice,  and  as  a  protection  from  the  Khampa 
brigands,  who  have  an  unpleasant  habit  of  cutting  down  first  the 
tents  and  then  the  owners.  The  caves,  on  the  other  hand,  are  readily 
defensible.  Thok-Daurakpa,  unlike  Thok-Jalung  and  Thok- 
Sarlung,  has  no  long  and  wide  excavations  in  which  all  the 
miners  work,  but  each  phukpa  has  its  own  gold  pit.  One  or  two  men 
are  generally  employed  in  quarrying  the  stone  in  which  the  gold  is 
found.  The  pieces  of  stone  are  hoisted  in  baskets  to  the  brink  of  the 
pit,  and  are  there  pounded  into  small  fragments,  which  are  washed 
as  at  Thok-Jalung.  From  the  foregoing  description  it  may  be 
inferred  that  the  Daurakpa  workings  are  in  quartz  veins,  but  it  is 
also  possible  that  the  gold  occurs  in  a  cemented  gravel  so-  hard  as 
to  require  crushing  to  liberate  the  gold.  Unfortunately,  there  is 
no  water  in  the  vicinity  of  the  gold  mines,  and  all  water  for  washing 
is  brought  from  a  stream  a  mile  distant  in  skins  on  donkeys  that  are 
specially  kept  for  the  purpose.  Nain  Singh  estimated  the  value  of 
the  gold  brought  annually  into  Gartokh  at  some  £8,000  sterling. 

Gold  mines,  generally  deserted,  have  been  reported  from 
various  places  by  the  explorers  who  have  dashed  into  Tibet  to  get  as 
near  Lhassa  as  possible  before  being  stopped  and  turned  back,  or 
who  have  crossed  Tibet  to  or  from  China  by  routes  north  of  Lhassa. 
These  explorers  are,  particularly,  Bower,  Carey,  Bonvalot,  Deasy, 
Littledale.  and  Rawling.     The  diggings  visited  by  the  last-named 


TIBET.  235 

in  1895  were  at  Pallo  Letok  (80°  30',  34°  45')  and  its  neighbourhood. 
He  heard  of  a  famous  goldfield,  Munnak  Thok  (Long.  81°  25'  E., 
Lat.  33°  10'  N.),  which  employed  500  miners.  In  those  actually 
crossed  by  Captain  Rawling,  the  shallow  pits  extended  for  miles  in 
a  scene  of '  dreary  desolation.  They  had  quite  recently  been 
abandoned,  for  the  water  races  and  dams  were  still  clearly  and 
sharply   defined. 

Of  late,  attention  has  been  directed  to  Tibetan  goldfields  by  the 
report  of  the  discovery  of  extensive  goldfields  by  the  indefatigable 
Central  Asian  explorer,  Dr.  Sven  Hedin.  An  examination  of  the 
brief  notes  supplied  by  him  makes  it  fairly  clear  that  those  newly 
found  are  but  a  northern  extension  of  the  already  known  Thok- 
Daurakpa  and  Sarka  Shya  goldfields.  Definite  figures  for  latitude 
and  longitude  are  not  available,  but  the  position  of  Dr.  Hedin's 
fields  is  probably  about  86°  east  longitude  and  somewhat  south  of 
the  34th  parallel  of  north  latitude. 

The  most  northerly  extension  of  the  main  Tibetan  goldfield  is 
apparently  the  northern  slope  of  the  Kuen-Lun  mountains.  Gold 
mining  in  alluvial  deposits  has  been  carried  on  there  certainly  for 
centuries.  The  principal  centres  are  Sorghak,  Kopa,  Akka  Tagh,  and 
Bokalik.  The  first  of  these  really  lies  in  eastern  Turkestan,  and  was 
visited  in  1906  by  Major  C.  D.  Bruce,  during  a  journey  from  India  to 
Pekin."  Sorghak  is  described  as  a  squalid  place,  lack  of  water  and 
an  all-enveloping  dust  being  its  chief  characteristics.  The  gravel  is 
worked  by  circular  shafts  from  40  to  100  feet  deep,  apparently^ 
indeed,  to  "  bottom,"  where  tunnels  are  driven,  and  the  pay  gravel 
sent  to  surface.  Owing  to  the  lack  of  water  Sorghak  is  a  "dry- 
blowing  "  field,  the  sand  being  winnowed,  and  the  operation  finished 
by  blowing  the  concentrates  over  felts. 

The  foregoing  auriferous  areas  are  all  in  Western  Tibet.  There 
are  two  goldfields  in  Eastern  Tibet.  The  first  of  these  is  in 
the  neighbourhood  of  Koko  Nor,  in  the  north-east.  According  to 
Mesny,  who  visited  some  of  these  placer  deposits,  the  alluvial  gravel 
is,  on  an  average,  20  feet  in  depth,  but  only  the  bottom  gravel  for  a 
couple  of  feet  above  the  rock  is  worth  washing.  The  gold  was  coarse, 
varying  in  size  from  that  of  a  turnip  seed  to  that  of  a  pea,  while 
occasionally  much  larger  nuggets  were  unearthed.  The  Gork  gold- 
fields  of  Rockhill  are  also  in  this  neighbourhood  (circa  101°  E.  long., 
35°  40'  N.  lat.).  They  were  discovered  about  1888,  and  were 
leased  by  the  Hsi-ning  Amban  (prefect)  to  a  Chinaman  for  180 
ounces  of  gold  per  annum.  In  less  than  two  years  about  3.000 
ounces  of  gold  had  been  taken  out.  Rockhill  records  gold  also  from 
Yuktu  Gol  and  the  Rajong  valley  south-west  of  Koko  Nor. 

"  Geog.  Journal,  XXTX,  1907,  p.  608. 


236  asia. 

The  Lithang  goldfields,  also  in  the  east,  are  not  in  Tibet  proper, 
but  in  Chinese  Tibet.  Here  the  workings  occur  along  the  banks 
of  the  Li  Chu.  About  3,000  ounces  are  produced  annually.  The 
implements  used  by  the  washers  are  very  crude,  a  hollowed-out 
log  serving  as  a"  long -torn."  According  to  Rockhill,  the  miners 
make  about  3s.  2d.  per  day,  but  this  is  probably  too  high  an  estimate. 

Between  Koko  Nor  and  Lithang  is  another  auriferous  area, 
viz.,  that  of  Jyekundo.  The  washings  there  are  apparently  very  poor, 
since  one  washer  obtaining  about  five-pence  worth  of  gold  for  four 
days'  work  expressed  himself  to  Rockhill  as  fairly  well  satisfied. 

The  outstanding  feature  of  all  these  Tibetan  goldfields  is  their 
lack  of  permanence.  Several  causes  apparently  co-operate  to 
cause  their  desertion.  They  may  be  exhausted  :  new  goldfields 
with  greater  potentialities  may  attract  the  diggers  :  the  fearful 
influences  of  jeng-shui  (fung-shui)  may  be  brought  into  operation  : 
or  the  diggers  may  be  crushed  by  the  officials.  The  first  and  the  last 
of  these  are  probably  the  most  potent.  When  the  Assistant- 
Commissioner  of  Kulu  visited  Thok-Jalung  in  1906,  he  found  that 
field  deserted,  and  was  told  that  all  the  diggers  had  gone  to  Thok- 
Dalung  (sic),  a  day's  journey  distant.  It  subsequently  appeared, 
however,  that  the  Jongpen  (Revenue  Commissioner)  of  Chaprang 
had  been  harassing  the  diggers  at  Thok-Jalung.  It  was  his  habit 
to  seize  all  the  gold  nuggets  found,  and  to  pay  for  them  in  brick  tea 
at  his  own  valuation.  He  had  even  tied  up  an  unfortunate  gold 
digger  by  the  heels,  and  had  him  flogged  to  death. 

The  reason  that  for  centuries  past  has  been  advanced  by  the 
Tibetans  themselves  to  account  for  the  desertion  of  their  goldfields 
is  that  in  each  given  case  the  spirits  of  the  earth  had  been  angered 
and  had  withdrawn  the  supply  of  gold.  They  have  always  believed 
that  the  nuggets  are  the  roots  from  which  new  gold  grows,  and, 
according  to  the  lamas,  have  always  replaced  some  of  the  gold  in 
order  not  to  deprive  the  earth  entirely  of  gold  seed.  The  diggers  are 
silent  on  this  last  point.  The  story  of  the  seed  gold  is  first  told  in 
detail  by  William  de  Rubrucjuis  (1254  a. d.),  and  has  since  been  re- 
peated by  most  writers  on  Tibet.  Again,  mining  in  a  country 
hallowed  by  the  graves  of  their  ancestors,  is,  from  the  Mongolian 
point  of  view,  abhorrent  to  the  feng-shui,  the  spirits  of  earth  and  air, 
who  have  long  been  accustomed  to  certain  habitations  and  will  not 
willingly  see  them  disturbed.  Strachey  relates  that  the  Manasarowar 
workings  were  deserted  because  a  digger  there  had  unearthed  a  small 
nugget  of  strangely  human  form — clear  evidence  that  the  spirits  were 
displeased.  Not  withstanding  these  stories,  it  may  be  taken  for 
granted  that  no  really  rich  field,  either  in  Tibet  or  in  China,  is 
deserted  solely  from  fear  of  feng-sh  u  i. 


TIBET.  237 

Of  the  source  of  Tibetan  gold  nothing  definite  may  be  said. 
From  the  scanty  scraps  of  geological  knowledge  we  possess  it 
may  be  inferred  that  the  goldfields  are  associated,  as  in 
India,  with  the  Archaean  schists  and  older  metamorphics.  The 
strike  of  the  line  of  goldfields  from  Rudok  to  the  Zilling  Cho,  as 
shown  on  the  accompanying  map,  would  appear  to  lie  northward 
and  parallel  to  the  crystalline  axis  running  through  the  neighbour- 
hood of  Lhassa,  as  mapped  by  Hayden  when  with  the  1906  punitive 
expedition/'  Again,  in  the  portion  of  the  Western  Kuen-Lun 
mountains  known  to  geologists,  the  mountain  axis  is  also  a  meta- 
morphic  schist.  By  the  degradation  of  these  older  rocks  the  aurifer- 
ous gravels  have  presumably  been  formed.  It  has  always  been  a 
matter  of  some  surprise  that,  with  the  drainage  from  the  goldfields 
apparently  falling  into  the  Yaro-Tsangpo,  there  were  no  auriferous 
deposits  along  that  river.  The  examination  of  Hayden's  concen- 
trates from  the  Tsangpo, 'J  the  lack  of  all  mention  of  gold  washings 
along  its  course,  and  the  writer's  own  examination  of  the  river 
near  Sadiya  (where  it  is  known  as  the  Dihong)  as  it  debouches  from 
the  Himalayas,  had  sufficiently  proved  that  gold  content  of 
the  river  gravels  was  unimportant.  A  new  light  is  there- 
fore thrown  on  the  matter  by  Dr.  Sven  Hedin's  discovery  of 
a  great  mountain  range  between  the  Tsangpo  and  the  line  of 
goldfields,  indicating  that  the  drainage  of  the  latter  is  toward 
the  great  central  Tibetan  basin  and  not  into  the  Tsangpo.  The 
eastward  trending  line  of  goldfields  apparently  represents  the 
course  of  the  drainage  channel  itself. 

From  the  foregoing  it  will  be  clear  that  no  opinion  may  be 
formed  as  to  the  richness  or  poverty  of  the  Tibetan  goldfields.  On 
the  one  hand,  large  nuggets  are  certainly  found,  and  the  gold 
generally  appears  to  be  coarse  ;  but,  on  the  other,  the  gold  diggers 
are  the  poorest  and  most  miserable  of  a  poor  and  wretched  people. 
The  gold  is  certainly  widely  spread,  but  the  severity  of  the  climate 
and  the  difficulties  of  working  are  not  paralleled  even  at  Nome  or  at 
Klondike. 


EASTERN  TURKESTAN. 

Little  is  known  of  the  auriferous  areas  of  this  region.  The 
streams  in  the  neighbourhood  of  Yarkand,  Khotan,  and  Karakash, 
all  flowing  north  from  the  Karakoram  mountains,  are  occasionally 
auriferous,  and  give  rise  to  a  limited  gold- washing  industry.  The 
mines  of  Khotan  have  already  been  mentioned  under  Tibet.     They 

"  Records  Geol.  Surv.,  India,  XXXII,  1905,  p.  160. 
0  Maclaren,  loc.  cit.  sup.,  p.  173. 


238  asia. 

are  located  at  Sorghak,  Kopa,  Chugalak,  Charchen,  and  Karatagh/' 
In  1875  there  were  said  to  exist  twenty-two  places  where  gold  might 
be  found,  but  of  these  only  the  above  five  were  being  worked. 

In  the  north-west  corner  of  Eastern  Turkestan,  gold  is  found 
only  in  the  right  affluents  of  the  Hi,  that  flow  from  the  granite 
ranges  of  the  Dzungaria  Ala-Tagh.  The  Tekes,  a  tributary  of  the 
Hi,  is  reported  to  carry  a  small  quantity  of  alluvial  gold. 


INDIAN 

India  offers  to  the  ordinary  prospector  an  extremely  uninviting 
field.  Its  auriferous  deposits,  both  vein  and  placer,  have  been 
carefully  prospected  and  assiduously  worked  for  at  least  twenty -five 
centuries — and  that  by  a  people  whose  skill  is  noteworthy,  and  whose 
patience  is  monumental.  The  great  spoil  heaps  of  quartz,  broken 
to  fragments  smaller  than  a  hazel  nut,  that  are  numerous  in  the 
immediate  vicinity  of  the  prospecting  works  of  the  ancients,  are 
lasting  and  sufficient  evidence  of  the  great  care  with  which  all 
possibly  auriferous  quartz  outcrops  were  sampled.  No  such  spoil 
heaps  remain  to  mark  the  outcrop  of  rich  veins,  for  the  stone  from 
these  was  carried  away  to  the  nearest  water,  and,  after  having  been 
most  laboriously  reduced  to  fine  powder  beneath  crushing  and 
rubbing  stones,  was  washed  for  its  contained  gold  in  a  rude  batea 
or  in  a  short  inclined  trough.  Prospecting  for  gold  veins  in  India, 
therefore,  resolves  itself  into  a  search  for  old  workings,  and  in  this 
quest  the  dolly  and  pan  are  useless.  An  eye  keen  to  detect  abnormal 
depressions  in  the  black  cotton  soil  of  the  Mysore  and  Hyderabad 
plateaux,  an  ability  to  trace  the  schistose  belts  in  which  the  quartz 
veins  lie,  a  colloquial  knowledge  of  a  Deccan  language  (preferably 
Kanarese),  and  finally  sufficient  guile  to  extract  information  from 
the  unwitting  ryot,  these  are  all  better  aids  towards  success.  Indi- 
cations of  the  proximity  of  gold-quartz  veins  are  sometimes  afforded 
by  the  presence  of  the  rude  stone  pestles,  mortars,  and  crushing 
mills  of  the  ancient  miners.  The  schists  in  which  the  veins  occur  are 
soft  and  easily  weathered  ;  often  the  only  hard  rock  in  a  schistose 
region  is  an  intrusive  diabase.  At  points  along  such  a  dyke  there 
may  be  found  on  its  surface  numerous  cup-shaped  depressions,  4  or 
5  inches  across,  and  about  the  same  in  depth,  in  which  the  larger 
fragments  of  quartz  were  broken  to  the  size  of  a  pea  before  being 
triturated  to  dust  beneath  a  stone  held  in  the  hand  and  rubbed 
backwards    and    forwards,   or   beneath  great  spherical  or  rudely 

a  Forsyth,  "  Mission  to  Yarkand,"  1875,  p.  475. 

h  Maclaren,  Min.  Jour.,  LXXXIV,  Aug.  15,  1908,  p.  198. 


INDIA.  239 

cylindrical    rocking    stones    weighing  from    a    hundredweight    to 
nearly  a  ton,  and  worked  in  all  probability  by  women.     The  rock- 
ing stones  leave  smooth-faced  shallow  depressions  in  the  bedrock 
that  are  easily  recognised  by  the  practised  eye.     Near  Wondalli, 
in   the    Nizam's  dominions,  many    huge,  rudely  spherical,  granite 
boulders  that  had  served  as  crushing-mills  in  ancient  times  were 
formerly  dotted  over  the  quartz-strewn  surface.     Of  these  only 
two  now  remain,  the  remainder  having  been  split  by  unimaginative 
stone-masons  to  build  the  bungalows  of  a  long-defunct  gold-mining 
company.     The  actual  position  of  the  anciently  worked  vein  is 
often  deeply  masked.     The  Southern  Deccan,  owing  to  lack  of  rain- 
fall, is  practically  treeless,  but  forms  on  its  surface  a  thick  black 
soil,  commonly  known  as  'l  cotton  soil."     From  the  same  lack  of 
rainfall  the  contour  of  the  surface  of  the  auriferous  country  where 
not  actually  flat  is  gently  undulating,  especially  when  the  schists 
possess  no  strengthening  ribs  of  hard  banded-quartzite  to  aid  them 
in  their  struggle  against  denudation.     Under  such  circumstances, 
the  old  pits  are  soon  filled  in,  and  all  traces  of  ancient  working  are 
completely  obliterated.     It  was  only  by  noting  the  existence  of  a 
short  chain  of  slight  depressions  in  the   cotton-soil  that  the  now 
well-known  Hutti  mine  was  discovered,  for  over  its  workings  there 
had  been  grown  many  a  crop  of  jowari  and  of  cotton.     A  single 
depression  would  have  completely  escaped  notice,  and  as  a  matter 
of  fact  the  chain  did  not  suggest  a  mine  until  1900,  although  the 
district  had  been   known  to  be  auriferous,  and  had,  indeed,  been 
prospected  for  some  thirteen  years.     Even  when  found  the  tenor 
of  the  quartz  in  many  of  the  old  workings  is  far  too  low  to  justify 
exploitation  under  modern  conditions,  for  there  can  be  little  doubt 
that  these  ancient  mines  were  worked  by  slave  labour.     Where, 
however,  the  veins  were  really  rich,  as  at  Kolar  and  at  Hutti,  they 
have  been  followed  down  for  great  depths,  in  the  latter  case  to  620 
feet  below  the  surface,  probably  the  greatest  depth  to  which  the 
ancients  reached  in  their  search  for  gold,  and  a  depth  the    more 
remarkable  in  view  of  the  hardness  of  the  rock  and  of  the   crude 
methods   of  mining  and  hoisting  then  in  vogue.      Fragments   of 
charcoal  in  old  levels  and  marks  of  fire  on  abandoned  faces  show  that 
the  laborious  method  of  "  fire-setting  "  was  practised. 

India  has,  through  all  the  ages  down  to  the  nineteenth  century, 
been  regarded  as  a  land  superlatively  rich  in  gold.  It  was,  for 
example,  long  thought  to  contain  that  Ophir  from  whence  Solomon 
drew  his  stores  of  gold — an  assumption  considered  to  be  finally 
proved  by  various  arguments  advanced  by  the  most  famous 
philologist  of  the  last  century.  But  these  philological  arguments  are 
now  deemed  of  doubtful  validity,  and  with  every  advance  on  our 
knowledge  of  the  history  of  ancient  India,  it  becomes    more  and 


240  ASIA. 

more  certain  that,  wherever  the  ships  of  Tarshish  journeyed,  it 
assuredly  was  not  to  the  coasts  of  India.  It  is  highly  improbable, 
considering  the  comparatively  advanced  state  of  civilisation 
prevailing  in  Southern  India  in  the  days  of  Solomon,  that  the 
voyagers  could  have  landed  on  its  shores  other  than  as  mere  traders. 
That  they  could  have  occupied  the  country  and  worked  its  gold 
mines  is  inconceivable  ;  and,  as  traders  they  could  have  taken 
nothing  to  India  with  which  to  appeal  to  the  inhabitants  of  that  self- 
contained  country  except  gold  and  silver — the  very  commodities 
they  are  supposed  to  have  brought  away.  Even  four  centuries 
before  the  Christian  era  India  was  famous  as  an  absorbent  of  gold 
and  silver,  and  in  later  centuries  even  to  the  present  time  the  flood 
of  gold  has  always  steadily  set  eastward  towards  Hindustan — a 
country,  indeed,  termed  "  the  sink  of  gold  ''  by  a  writer  of  the 
Middle  Ages.  It  may  be  concluded,  therefore,  that  the  enormous 
hoards  of  gold  that  have  fallen  as  booty  to  various  conquerors  in 
India,  have  resulted  from  the  long-continued  operations  of  trade, 
and  are  in  no  wise  indicative  of  rich  mines  within  the  country.  The 
Ophir  fable,  as  regarding  India,  was  vigorously  exploited  from 
1877  to  1879,  in  order  to  boom  the  ill-fated  mines  of  the  Wainaad, 
near  the  Malabar  coast,  where  hundreds  of  thousands  sterling 
were  recklessly  squandered  in  useless  work  and  useless  machinery, 
and  millions  in  promotion  money. 

Again,  India  is  the  home  of  the  gold-digging  ants  of  the  Greek 
historians — a  story  that,  notwithstanding  many  attempts  at  eluci- 
dation, is  to-day  an  even  greater  mystery  than  it  was  to  Herodotus 
more  than  2,300  years  ago.  For  these  ants  lived  in  the  parched 
sandy  deserts  of  Northern  India,  and  collected  gold  in  great  quantity 
at  the  mouths  of  their  burrows  ;  and  so  large  and  fierce  and  swift 
were  they  that  the  gold  they  gathered  might  be  collected  by  the 
Indians  only  by  stealth  and  subtlety.  Space  forbids  the  discussion 
of  this  interesting  story,  which  is  repeated,  with  additions  in  his  own 
inimitable  fashion,  by  the  ingenuous  chronicler  of  the  travels  of  Sir 
John  Mandeville.  Notwithstanding  the  dicta  of  Professor  Schiern 
and  Sir  Henry  Rawlinson,  who  place  the  scene  of  the  labours 
of  the  ants  amid  the  snows  of  the  Tibetan  plateau,  it  is  considered 
by  the  present  writer,  from  the  internal  evidence  furnished,  that, 
if  the  story  is  to  be  accepted  at  all,  its  deserts  are  to  be  placed, 
not  on  the  Chang-thang — the  desolate  wind-swept  plateau  of 
Tibet — but  in  Eastern  Turkestan,  in  the  neighbourhood  of 
Yarkand. 

From  the  time  of  the  Greek  historians  down  to  the  nineteenth 
century,  nothing  is  known  of  the  history  of  the  gold  mines  of  India. 
Of  all  the  ancient  civilised  peoples  of  the  world,  the  Hindu  has 
proved  the  worst  historian.     Possessing  several  scripts,  he  never- 


INDIA.  241 

theless,  as  a  chronicler  falls  far  behind  the  Polynesian,  dependent 
only  on  oral  tradition.  It  was  not,  indeed,  until  the  advent,  about 
1000  a.d.,  of  the  Musalman  conqueror,  Mahmud  of  Ghuzni,  through 
the  eastern  passes  of  Afghanistan  that  historical  record  lifts  the 
curtain  thrown  over  events  in  India.  But  detailed  as  the  subsequent 
Musalman  accounts  are,  there  is  in  them  no  mention  of  the  ancient 
gold  mines  of  Southern  India.  It  is  certain  that  they  were  being 
worked  in  the  beginning  of  the  Christian  era.  Pliny  (a.d.  77)  says  : 
"In  the  country  of  the  Narese  (Nairs),  beyond  the  mountain  Capitalia 
(Mount  Abu  in  Rajputana),  there  are  numerous  mines  of  gold  and 
silver  in  which  the  Indians  work  very  extensively  " — a  description 
perhaps  sufficiently  specific  to  indicate  the  gold  mines  of  Hyderabad 
and  Mysore. 

The  first  Mahomedan  invasion  of  the  Deccan  was  made  by  the 
Khilji  emperor,  Ala-ud-din,  in  1294  a.d.,  and  from  thence  a  fairly 
connected  account  of  the  course  of  events  may  be  made  out  from  the 
gossipy  chronicles  of  various  writers,  and  notably  from  those  of  the 
cultured  Persian,  Mahomed  Kazim  Ferishta,  who  wrote  at  great 
length  in  Bijapur  about  1600  a.d.  Quoting  from  an  old  record,  he 
describes  the  delight  with  which  Ahmed  Shah  Wully  Bahmani  in 
his  campaign  of  1425  a.d.  obtained  possession  of  an  unimportant 
diamond  mine  at  Kullum,  but  nowhere  is  there  any  mention  of  gold 
or  of  gold  mines.  That  this  neglect  was  not  due  to  indifference 
towards  the  subject  is  evident  from  the  fact  that  he  describes  the 
discovery,  in  998  a.d.,  of  a  now  unknown  gold  mine  in  far-away 
Seistan  in  South-western  Afghanistan,  and  also  mentions, 
the  trifling  gold-washings  of  Kumaon  in  Northern  India- 
Further,  the  great  Vijayanagar  empire,  against  which  the 
might  of  the  confederated  Mahomedan  kingdoms  strove 
so  long  in  vain,  and  which  alone  saved  Southern  India  from 
Mahomedan  domination,  does  not  appear  to  have  derived  any 
of  its  wealth  from  gold  mines.  Retaining,  as  it  did,  practically 
undisturbed  possession  of  the  auriferous  areas  of  Gadag  and  of 
northern  Mysore  from  the  beginning  of  the  fourteenth  to  the  middle 
of  the  sixteenth  centuries,  it  is  in  the  highest  degree  improbable 
that,  had  the  gold  mines  been  worked  at  any  time  during  the 
existence  of  the  empire,  at  least  their  position  would  have 
remained  unknown  to  the  rapacious  Mahomedan  invader. 
Nor  are  gold  mines  mentioned  by  any  of  the  numerous 
European  adventurers — Nicoli  di  Conti,  Varthema,  Federici, 
Nikitin  (1470),  or  Barbosa  (1508) — whose  way  from  Goa  to 
the  capital  city  of  Vijayanagar,  then  at  the  height  of  its 
glory,  led  them  so  close  to  the  mines  at  Gadag.  The  Vijayanagar 
empire  was  swept  out  of  existence  in  1565  a.d.  at  the  bloody  battle 
of  Talikota,  a  small  village  lying  some  distance  across  the  Kistna 

Q 


242  ASIA. 

river  from  the  Hutti  mines.  It  may,  therefore,  be  finally  concluded 
that  the  ancient  gold  mines  of  Southern  India  were  forgotten  by 
1300  a.d.,  thus  rendering  it  probable  that  they  were  not  worked,  at 
least  on  a  large  scale,  subsequent  to  1000  a.d.  At  Kolar,  however, 
it  is  known  that  pillar-robbing  and  rooting  among  the  ancient 
workings  was  practised  in  desultory  fashion  even  at  the  end  of  the 
eighteenth  century. 

Geology. — Except  on  the  edge  of  the  Western  Ghauts,  the 
auriferous  vein  areas  of  India  lie  on  a  broad  treeless  plateau  about 
2,200  feet  above  sea-level.  The  rainfall  varies  with  proximity  to 
the  coast,  the  central  portion  of  the  plateau  receiving  always  less  than 
20  inches  per  annum.  The  known  gold  belts  of  Southern  India, 
with  one  doubtful  exception  (Wainaad),  lie  in  the  Dharwar  (Transi- 
tion) series  of  Archaean  rocks,  which  rest,  so  far  as  can  be  seen, 
on  a  gneissoid  granite.  The  relations  of  the  Dharwar  schistose  rocks 
to  the  granite  are  far  from  clear,  and  are  further  obscured  by  the 
presence  of  younger  granites  intrusive  both  into  the  gneiss  and 
into  the  schists,  but  into  the  latter  generally  only  along  or  near  their 
gneiss  contacts.  Various  views  have  been  held  as  to  these  relations 
and  the  question  remains  an  open  one;  but  the  simplest,  and  the 
most  probable,  is  that  the  gneiss  is  the  ancient  granite  floor  on 
which  the  lavas  and  sediments  now  forming  the  schistose  complex 
were  deposited. 

The  Dharwar  rocks  are  typically  developed  as  a  series  of  long, 
narrow,  fairly  parallel  belts,  extending  from  near  Belgaum  in  the 
Bombay  Presidency,  and  from  the  Kistna  river  in  the  Nizam's 
dominions,  southward  through  the  Mysore  State.  The  northern 
extension  of  the  Dharwar  bands  is  in  nearly  all  cases  concealed 
beneath  Cambrian  or  pre-Cambrian  quartzites,  or  beneath  the 
Deccan  Trap.  Five  main  bands  may  be  distinguished,  and  are 
here  enumerated  in  their  order  from  west  to  east  : — 

I.  The  Castle  Rock  Band. — This  band  lies  along  the  eastern 
frontier  of  the  Portuguese  territory  of  Goa,  and  probably  extends 
towards  the  south-south-east  to  join  the  schist  band  shown  by  the 
work  of  the  Mysore  Geological  Survey  to  exist  near  Honnali.  It 
may  also  be  continuous  as  far  south  as  the  scarp  overlooking  Manga- 
lore,  but  very  little  is  known  concerning  its  extension,  since  it 
lies  in  a  region  of  heavy  rainfall,  and  consequently  of  dense  jungle. 
In  the  north,  however,  where  it  was  most  closely  examined  by  the 
writer,  it  appears  to  contain  the  least  metamorphosed  members  of 
the  Dharwar  system,  viz.,  dolomitic  limestones  and  quartzites, 
the  latter  only  occasionally  becoming  quartz-schists.  No  auriferous 
veins  have  as  yet  been  found  along  this  band. 

II.  The  Dharivar-Shimoga  Band. — This  band  emerges  from 
beneath  the  Deccan  Trap  in  the  neighbourhood  of  Belgaum,  runs 


INDIA. 


243 


south  to  the  station  of  Dharwar  (from  which  the  whole  series  was 
named  by  Foote),  enters  Mysore  territory  near  Harihar,  and  passes 
south  by  Tarikere  until  it  finally  frays  out  in  thin  bands.  The 
supposed  Dharwar  rocks  of  Coorg  and  of  the  Wainaad,  are  possibly 


\gS<Joa 

iwarrna gee's  ;.<  / 
V      a^t;Castle  R 


Fig.  90.     Sketch  Map,  showing  Dharwar  Schist  Bands  in  Southern'  India. 

outliers  of  this  great  band.  Ancient  gold  workings  are  known  on  it 
west  of  Ranibennur,  and  in  the  Mysore  State  near  Ajjampur.  The 
rocks  of  the  band  were,  on  the  whole,  evidently  original  sedimentary 
deposits,  being  now  mainly  chlorite-schists. 


244  asia. 

777.  The  Gadag-Seringapatam  Band. — This  is  one  of  the  longest 
and  best-defined  of  the  Dharwar  belts.  Omitting  a  small  northern 
outlier  at  Nargund,  it  may  be  said  to  commence  near  the  town  of 
Gadag,  and  to  have  a  general  south-south-east  trend,  passing  by 
Chitaldroog  and  Huriyur,  and  swinging  to  the  south-south-west  as  it 
approaches  its  southern  termination  near  Seringapatam.  Several 
mining  districts  occur  along  the  course  of  this  band.  The  chief  is  that 
of  Gadag,  but  numerous  old  workings  are  known,  and  have  been 
re-opened,  in  the  Tumkur  district  of  Mysore.  The  country  of  the 
gold-quartz  veins  of  this  belt  is  an  original  sedimentary  rock, 
now  mainly  chlorite-schist  and  argillite,  but  associated  with  boulder 
beds,  and,  in  the  south,  with  dolomitic  limestones.  The  Nanjangud 
auriferous  area  south  of  Seringapatam  is  probably  on  this  belt. 

IV.  The  Hunugund  Band. — This  strikes  across  the  south-west 
corner  of  the  Nizam's  dominions  to  and  beyond  Bellary.  No 
auriferous  veins  are  known  along  its  course,  although  old  workings, 
possibly  for  gold,  occur  near  Tarwaragheri. 

V.  The  Maski  Band. — The  Maski  belt  lies  entirely  within  the 
Nizam's  dominions,  between  Raichur  and  Mudgal,  and  for  the  most 
part  south  of  the  Kristna  river.  It  comprises  three  disconnected 
portions,  of  which  the  central  one  containing  the  Hutti,  Topuldodi, 
and  Wondalli  mines,  is  alone  of  economic  importance.  The 
principal  rocks  are  here  hornblende-schists. 

In  addition  to  the  main  bands  above  outlined  there  are  several 
smaller  bands.  The  largest  of  these,  in  the  Sandur  State,  contains 
extensive  deposits  of  lateritic  manganese.  Of  the  smaller,  the  Kolar 
and  Anantapur  belts  are  alone  of  importance.  It  is  from  the  former, 
of  course,  that  nearly  all  the  gold  obtained  in  India  during  the  past 
twenty  years  has  been  derived.  The  main  bands  and  outliers 
alike  apparently  represent  the  bottoms  of  great  earth  folds  generated 
by  a  pre-Cambrian  east-north-east — west-south-west  compression  ; 
but  there  is  also  evidence  that  some  may  owe  their  preservation  to 
faulting  down.  Speaking  generally,  the  schistosity  of  the  Dharwar 
belts  decreases  from  east  to  west  ;  and,  further,  on  passing  from 
east  to  west  sedimentary  rocks  assume  greater  and  greater  impor- 
tance, until  on  the  Western  Ghauts  igneous  rocks  are  rare.  Since 
the  work  of  Mr.  R.  B.  Foote  in  1886,  and  with  the  exception  of  a 
season's  work  by  the  present  writer  in  1904-5,  nothing  has  been 
done  towards  demarcating  the  boundaries  within  British  India  of 
these  important  belts.  In  the  State  of  Mysore,  however,  the  dis- 
position and  character  of  the  Dharwar  bands  are  well  known, 
owing  to  the  excellent  work  of  the  members  of  the  Mysore  Geological 
Survey. 


INDIA.  245 

The  Dharwar  series  is  a  complex  aggregate  of  highly  meta- 
morphosed, rocks,  which  are  yet  not  so  greatly  altered  as  to  render 
it  impossible  to  discern  the  original  nature  of  some  of  its  constituents  ; 
and  a  separation  into  igneous  and  sedimentary  members  is  often 
practicable.  Of  the  relative  ages  of  the  two  little  can  be  said. 
Among  the  more  easily  recognisable  sedimentary  rocks  are  boulder- 
beds  or  "  conglomerates,"  pebbly  grits,  quartzites,  argillites, 
chloritic  schists,  and  limestones.  The  boulders  of  the  boulder-beds 
are  embedded  in  a  chloritic  schist  matrix,  and  are  seldom  so  closely 
aggregated  as  to  deserve  the  term  conglomerate.  The  quartzites 
are  in  places  metamorphosed  into  quartz-schists.  They  are  often, 
and  especially  in  the  Castle  Rock  Band  on  the  edge  of  the  Western 
Ghauts,  horizontally  bedded,  but  yet,  in  conformity  with  the 
prevailing  direction  of  pressure,  they  have  had  impressed  on  them 
a  distinct  north-north-west — south -south-east  schistose  cleavage. 
Since  the  bedding  and  cleavage  are  very  nearly  of  equal 
value  in  their  resistance  to  weathering,  the  same  bed  often 
shows  within  a  few  yards  a  sudden  transition  from  hori- 
zontality  to  a  steep  north-easterly  dip,  the  last  being  that 
of  the  foliation.  Limestones  are  not  abundant,  and  reach  their 
greatest  development  in  the  dolomitic  members  of  the  Castle  Rock 
Band  that  underlie  the  above-mentioned  quartzites.  The  limestones 
contain  in  places  thin  interbedded  bands  of  chrysolite,  which  show 
by  their  numerous  contortions  and  intense  crumpling  that  they  have 
yielded  by  physical  displacement  to  a  lateral  pressure  that,  owing  to 
chemical  reconstitution  of  the  lime  and  magnesia  carbonates,  has 
left  no  visible  effect  on  the  limestone.  Another  exposure  of 
limestone  occurs  at  Dodrampur,  south  of  Chiknayakanhalli,  in  the 
Mysore  State.  By  far  the  most  characteristic  rock  of  the  series, 
only  to  be  found,  as  far  as  the  writer  is  aware,  in  the  sedimentary 
division  of  the  Dharwars,  is  a  well-banded,  generally  much  contorted, 
hsematite-magnetite-quartz  rock  of  obscure  origin.  This  rock, 
though  forming  but  a  relatively  small  proportion  of  the  complex, 
yet  exercises  a  most  potent  influence  on  Dharwarian  scenery.  Its 
superior  hardness  enables  it  to  form  the  mountain  ridges  of  the  belts 
while  the  softer  chloritic  schists  and.  argillites,  with  which  it  is  in 
India  invariably  associated,  sink  down  to  intervening  valleys  and 
plains.  These  haematite-quartz  rocks,  and  consequently  the 
mountain  ridges,  invariably  conform  to  the  general  strike  of  the 
foliation. 

The  great  degree  of  contortion  shown  by  them  indicates  that 
they  have  shared  in  all  the  metamorphism  to  which  the  Dharwars 
have  been  subjected,  and  further  that  if,  as  has  been  assumed  by 
some  authorities,  they  owe  their  origin  to  silicification  along  shearing 
planes,  such  silicification  took  place  long  prior  to  the  period  of  greatest 


246  asia. 

metamorphic  activity.  But  shearing  planes  are  compatible  only 
with  great  dynamic  movements,  such  as  are  known  to  have  taken 
place  in  this  region  long  after  the  formation  of  the  hsematite-quartz 
bands.  The  most  reasonable  explanation  of  the  origin  of  these 
peculiar  rocks  is  that  suggested  by  Van  Hise  in  regard  to  not  greatly 
dissimilar  American  occurrences.  He  supposes  that  they  represent 
original  highly  ferruginous  shales,  that,  owing  to  a  re-arrangement  of 
the  component  minerals  proceeding  from  the  natural  segregative 
tendency  of  iron  oxides  and  of  silica,  formed,  before  they  were 
depressed  below  the  reach  of  oxidising  influences,  normal  ferruginous 
cherts  containing  simply  limonite  and  cherty  matter,  more  or  less 
banded.  Passing  from  the  upper  zone  of  weathering,  and  being 
subjected  to  the  stress  of  orogenic  movements,  the  bands  were  con- 
torted and  subjected  to  active  dehydration,  which  converted  the 
limonite  into  haematite.  Where  pure  iron  carbonates,  such  as  are 
now  found  at  the  surface  in  many  Dharwarian  areas,  occurred  with 
the  limonite  the  depression  into  the  region  of  sulphide  waters  pro- 
duced magnetite.  Where,  however,  the  descending  iron  carbonates 
were  not  pure,  but  contained  lime  and  magnesia,  and  came  within 
the  influence  of  silicious  waters,  actinolite,  griinerite,  or  kindred 
minerals  were  formed.  Such,  no  doubt,  was  the  origin  of  the  gedrite- 
bearing  rocks  described  by  the  Mysore  Geological  Survey.  The 
banding  of  the  quartz-rock  is  occasionally  so  fine  as  to  be 
resolvable  only  under  the  microscope. a  Similar  rocks  are  known 
in  the  Archaean  rocks  of  Western  Australia  and  in  Rhodesia  ; 
they  have  recently  been  described  from  the  latter  country  under 
the  designation  of  'banded  ironstones."  In  Western  Australia 
they  are  known  as  "  laminated  quartzites." 

The  members  of  the  Dharwars  derived  from  igneous  rocks  are 
mica-schists,  hornblende-schists,  certain  chloritic  schists,  amphi- 
bolites,  felsites,  and  quartz-porphyries,  representing  probably  a 
succession  of  fairly  basic  to  acidic  rocks,  such  as  may  be  met  with  in 
many  a  younger  volcanic  region.  The  origin  of  the  mica-schists  is 
not  clear,  but  some  of  the  hornblende-schists  retain  sufficient  of  the 
original  structure  to  indicate  their  diabasic  nature,  while  in  some 
light-coloured  varieties  the  ophitic  structure  is  so  clear  that  the  rocks 
may  fairly  be  termed  diabase-schists.  Where  they  have  been  in- 
fluenced by  the  intrusion  of  younger  granites,  the  hornblende-schists 
lose  their  schistose  structure,  and  by  reconstitution  of  their 
fragmentary  felspars  and  hornblendes,  assume  a  truly  dioritic 
habit.  No  trace  remains  of  original  pyroxene,  but  certain  hornblende- 
schists,  and  notably  those  of  Kolar,  when  near  the  intrusive  granite, 
contain  veinlets  of  secondary  augite,  which,  in  the  sections  in  the 

a  Maclaren,  Trans.  Inst.  Min.  Met.,  XVI,  1907,  p.  1. 


INDIA.  247 

writer's  collection,  appear   to  owe  their  origin   to  pneumatolytic 
action. 

Throughout  the  whole  Dharwarian  series,  as  well  as  through 
the  adjacent  crystalline  rocks,  there  ramify  numerous  diabasic 
and  doleritic  dykes  that,  showing  no  schistose  structure  and  no 
trace  whatever  of  deformation,  are  obviously  later  than  the  period 
of  the  final  metamorphism  of  the  enclosing  rock.  They  may, 
however,  be  correlated  with  some  degree  of  probability  with  certain 
lava  flows  in  the  Cheyair  group  of  the  Lower  Cuddapah  System.  The 
microscopic  characters  of  these  flows  have  been  described  with  some 
detail, a  and  their  petrographic  similarities  to  the  dykes  of  the  Madras 
Presidency  pointed  out.  Their  similarity  to  the  dykes  of  Western 
India  is  no  less  striking,  an  augite-diorite  lava  group  perhaps  repre- 
senting best  the  majority  of  the  western  dykes.  The  determination 
of  the  age  of  these  dykes  is  a  matter  of  some  importance,  as  will  be 
seen  later  when  considering  the  two  periods  of  Indian  auriferous 
activity. 

In  India,  outside  the  typical  southern  areas,  the  only  rocks  that 
may  reasonably,  on  the  evidence  available,  be  grouped  with  the 
Dharwars,  are  the  auriferous  schists  and  phyllites  of  Chota  Nagpur, 
and  probably  also  those  of  the  great  Aravalli  system  of  N.W.  India. 
The  Aravallis  possess  the  same  general  direction  of  foliation  as  the 
Dharwars,  and  have  been  apparently  subjected  to  the  same  com- 
pressive force.  To  the  foregoing  rocks  it  may  eventually  be  found 
necessary  to  add  the  schists  of  Behar  and  of  Shillong,  in  the  north- 
east of  India. 

The  relations  of  overlying  rocks  to  the  Dharwars  are  those  of 
absolute  unconformity.  Where  contacts  have  been  observed,  the 
younger  Transition  beds  lie  horizontally,  or  at  low  angles,  on  the 
upturned  and  denuded  edges  of  the  Dharwars.  The  latter  have 
suffered  from  long  seons  of  dynamic  metamorphism ;  the  former  have 
hardly  been  disturbed,  preserving,  for  example,  at  the  ancient  hill 
fort  of  Nargund,  even  their  ripple-markings  as  clearly  defined  to-day 
as  when  they  were  first  laid  down  on  the  shores  of  a  Cambrian  sea. 
An  enormous  gap  in  time  is  therefore  indicated  by  this  unconformity. 

The  younger  rocks  contain  no  fossils  and  are  perhaps  Cambrian 
or  even  pre-Cambrian  in  age.  They  are,  in  the  main,  slates,  con- 
glomerates, and  quartzites,  the  last  being  occasionally  so  little 
compacted  as  to  rather  deserve  the  name  of  sandstones.  In  their 
typical  areas  they  are  preserved  in  broad  basins — the  chief  being  the 
Cuddapah  (Kadapa),  and  the  Kaladgi  basins.  The  representatives 
of  these  rocks  in  Northern  India  must  be  sought  for  in  the  Bijawars 
(Gwaliors). 

a  Lake,  Rec.  Geol.  Surv.  India,  XXIII,  p.  259 ;  Holland,  lb.  XXX,  p.  16. 


248  asia. 

The  auriferous  quartz  veins  of  the  Dharwars  may  most  readily 
be  divided  into  two  groups  :  (a)  those  which  occur  in  hornblendic 
schists,  and  (6)  those  occurring  in  argillites  and  chloritic  schists.  The 
best  known  of  the  former  are  those  of  the  Kolar  goldfield  in  Mysore, 
and  of  the  Hutti  field  in  the  Nizam's  dominions.  The  latter  division 
includes  those  of  the  Gadag  field  and  the  Dharwar  belt  proper.  A 
closer  examination,  however,  shows  that  the  veins  are  capable  of  a 
genetic,  and  therefore  a  better,  classification,  indicating  two  distinct 
and  long-separated  periods  of  auriferous  activity.  The  first  is  to  be 
associated  with  the  period  of  the  general  dynamic  metamorphism 
of  the  Dharwars,  and  finds  expression  in  the  veins  of  bluish-grey  to 
bluish-black  quartz  that  furnish  the  gold  of  Kolar  and  of  Hutti. 
Microscopic  sections  of  this  quartz,  especially  from  the  Hutti  mine, 
show  that  it  has  been  subjected  to  all  the  metamorphism  that  has 
affected  the  enclosing  rocks.  Its  structure  is  decidedly  schistose, 
and  its  dark  colour  may  be  considered  to  be  due  to  total  internal 
reflection  from  strain  surfaces.  Its  gold  is  nearly  always  internal, 
a  certain  proof  of  contemporaneous  deposition  of  gold  and  of  silica. 

The  second  period  of  auriferous  activity  may  with  equal  clear- 
ness be  associated  with  the  great  intrusion  of  diabasic  and  doleritic 
magmas  already  shown  to  have  occurred  in  Lower  Cuddapah  times. 
The  heat  furnished  by  these  dykes  set  in  motion  siliceous  solutions 
carrying  gold,  and  the  white  quartz  veins  of  Kolar,  Hutti,  and  Gadag 
were  the  result.  On  the  first  two  fields  the  white  quartz  is  often 
found  in  the  same  fissure  as  the  older  dark  variety,  doubtless 
deriving  some  of  its  gold  from  the  latter.  When  examined  under 
the  microscope  the  white  quartz  shows  no  trace  of  schistose  structure 
and  no  further  strain  phenomena  than  are  normal  in  the  quartz  of 
ordinary  veins. 

The  veins  of  both  periods  show  a  decided  tendency  towards 
lenticular  and  overlapping  structure — the  world-wide  characteristic 
of  quartz  veins  in  schistose  rocks,  and  indeed  the  natural  result  of 
deposition  along  foliation  planes.  On  the  Gadag  field  the  younger 
are  the  more  important  veins,  occurring  in  a  carbonaceous  argillite, 
which  is  studded,  as  might  be  expected,  with  pyrites.  The  quartz 
lenses  of  the  area  are  connected  by  graphitic  lode-formations,  and  the 
main  Gadag  reef  system  appears  to  lie  within  what  was  originally 
a  highly  carbonaceous  band  in  the  argillites.  In  the  older  quartz 
veins  the  gold-quartz  occurs  in  "  shoots,"  those  of  the  Kolar  vein 
furnishing  probably  the  best  example  known  of  this  form  of  aggre- 
gation of  gold. 

No  strong  or  well-defined  veins  have  been  found  associated 
with  the  Dharwars  of  Chota  Nagpur  in  Northern  India.  The  few 
that  have  been  determined  are  small  and  poor,  and  evidently  fall 
within  the  second  or  younger  group,  as  outlined  above.     They  are 


INDIA.  249 

associated  with  a  tremendous  dioritic  outburst  not  greatly  dis- 
similar from  those  already  described,  and  which,  known  as  the 
Dulma  Trap,  sweeps  in  an  arc  of  a  circle  through  the  Singbhum 
Division.  No  auriferous  veins  are  known  to  occur  in  the  Aravallis 
of  North- West  India. 

Kolar. — The  Kolar  goldfield  lies  about  2,700  feet  above  sea 
level,  towards  the  eastern  edge  of  the  open  grass-covered  Mysore 
uplands.  The  nearest  large  town  is  Bangalore.  The  climate, 
though  hot,  is  healthy,  and  residence  there  entails  none  of  those 
trials,  amounting  at  times  to  positive  suffering,  that  must  be  endured 
by  unfortunate  dwellers  in  the  "  plains  "  of  India.  The  average 
annual  rainfall  is  31  inches,  an  amount  very  small  when  the  latitude 
of  the  field  is  taken  into  consideration.  Until  recently,  therefore, 
there  has  always  been  some  difficulty  in  obtaining  sufficient  water 
for  milling  and  domestic  purposes,  since  none  of  the  mines  make  much 
water.  The  recent  connection  of  the  field  with  the  Betamangalam 
tank  or  reservoir,  which  lies  a  few  miles  to  the  north-east,  has  now 
ensured  a  plentiful  supply  for  the  field. 

The  modern  history  of  the  Kolar  goldfield  opens  in  1802  with 
the  examination  of  the  outcrops  by  Lieut.  Warren,  of  H.M.  33rd 
Regiment,  who  was  then  engaged  in  surveying  the  Eastern  Mysore 
frontier.  While  camped  at  the  Betamangalam  tank,  rumours  of 
the  existence  of  gold  at  the  small  village  of  Wurigam  (Ooregaum) 
reached  him.  He  paid  a  visit  to  the  spot,  set  a  number  of  women 
to  work,  and  collected  a  small  quantity  of  gold.  While  thus  en- 
gaged he  heard  that  gold  was  being  extracted  from  a  spot  about  a 
mile  west  of  the  neighbouring  village  of  Marcupam  (Marikuppam). 
Thither  he  accordingly  repaired,  and  descended  two  mines,  which 
were  no  more  than  30  and  50  feet  deep  respectively.  He  employed 
several  men  in  collecting  quartz,  but  obtained  only  2  grains 
gold  as  the  result  of  two  days'  labour.  As  he  was  dependent  on  the 
honesty  of  native  washers,  he  shrewdly  "remarks  that  it  was  in  all 
probability  not  a  true  return.  According  to  the  natives,  these 
mines  had  been  known  for  many  years,  and  had  indeed  been  tried  by 
Tippoo  Sahib,  who  abandoned  the  experiment  after  a  few  weeks' 
work.  The  trial,  however,  appears  to  have  been  conducted  in  a 
very  perfunctory  manner,  for  the  Brahmin  in  charge  of  the  workmen 
never  visited  the  scene  of  operations.  Lieut.  Warren  also 
made  numerous  trials  in  the  sands  of  the  watercourses,  in  nearly 
all  cases  obtaining  a  few  fine  colours  of  gold.  For  many  years  after 
Warren's  visit  fugitive  references  to  the  gold  of  Mysore,  mainly 
quotations  from  his  description,  appear  in  the  publications  of  the 
period.  It  appears  that  the  natives  at  Marikuppam  continued  to 
burrow  among  the  old  workings  until  1859,  but  so  crude  and   so 


250  ASIA. 

dangerous  were  their  methods  that,  in  their  own  interests,  they  were 
finally  prohibited  from  working  underground  by  Sir  Mark  Cubbon, 
then  Commissioner  of  Mysore.  About  the  same  time  a  syndicate  of 
Bangalore  military  residents  obtained  a  concession  and  commenced 
to  work  at  Ooregum.     Their  operations  were  unsuccessful. 

The  pioneer  of  the  present  industry  was  undoubtedly  M.  F. 
Lavelle,  a  retired  soldier,  who  had  served  with  his  regiment  during 
the  Maori  war  in  New  Zealand,  and  had  there  also  learned  something 
of  gold-mining.  In  1873  he  applied  to  the  Mysore  Government  for 
the  exclusive  right  to  prospect  in  the  Kolar  district,  mainly  for  coaL 
Y\liether  the  mention  of  coal  was  merely  a  finesse  or  not  is  now  not 
clear,  but  at  any  rate  his  attention  was  soon  turned  towards  gold. 
He  commenced  operations  in  1875,  and  in  1876  handed  over  his  con- 
cessions to  a  small  syndicate  that  imported  two  Australian  miners,, 
but  spent  its  small  capital  (£5,000)  with  little  or  no  return.  Fresh 
capital  was  obtained,  and  in  1879  a  little  gold  quartz  was  obtained, 
the  find  resulting  in  the  formation  of  a  small  company  (the  original 
Ooregum  Company  of  Madras)  with  a  capital  of  Rs.  100,000  (£10,000). 
Further  discoveries  of  gold-quartz  in  1880  brought  several  mining 
engineers  from  the  Wainaad,  then  in  the  throes  of  a  vigorous 
"  boom,"  and  the  concession  was  promptly  purchased  for  £75,000. 
The  first  crushing  took  place  in  December,  1880,  when  40  tons  were 
treated  for  42  ounces  gold.  The  Wainaad  boom  had  now  spread  to 
Mysore,  and  by  July,  1881,  eleven  companies  had  been  formed, 
with  an  aggregate  capital  of  £1,216,000,  of  which  no  less  than 
£641,000  had  been  paid  to  the  vendors  in  cash  and  shares,  but  mainly 
cash.  During  the  height  of  the  boom,  the  wildest  speculations 
were  indulged  in.  The  newspapers  of  the  time  contain  grave  dis- 
cussions concerning  the  serious  effect  on  the  world's  currency  of  the 
future  gold  output  of  an  area  that  had  then  produced  to  European 
labour  and  capital  certainly  less  than  100  ounces  of  gold,  and  had,  as 
future  operations  were  destined  to  show,  hardly  a  single  ounce 
"  in  sight." 

On  the  field  itself  operations  appear  to  have  been  attended 
with  considerable  lack  of  management.  Large  European  staffs 
were  imported,  suitable  quarters  for  these  were  built  at  great  ex- 
pense, costly  milling  machinery  was  brought  to  the  field,  and  the 
little  money  thus  left  for  true  mining  was  frittered  away  in  sinking 
numerous  surface  shafts.  Little  or  no  gold  was  found,  and  as  the 
companies  approached  the  end  of  their  resources  they  endeavoured 
to  avert  disaster  by  rapid  changes  of  management,  thus  profiting 
as  little  as  could  be  by  the  local  experience  gained  by  mistakes. 
By  the  end  of  1883  nearly  all  the  companies  were  moribund.  In 
October  of  that  year  a  meeting  was  held  in  London  which  was 
destined  to  affect  materially  the  fortunes  of  the  Kolar  field.     Of  a 


INDIA.  251 

capital  of  £135,000  the  Mysore  company  had  but  £18,000  unexpended 
and  the  point  was  debated  among  the  shareholders  whether  it  was 
better  to  distribute  the  money  or  to  carry  on  with  what  appeared  at 
best  to  be  a  forlorn  hope.  In  the  end  it  was  decided  to  continue,  the 
meeting  being  greatly  influenced  by  the  strongly  expressed  opinions 
of  Captain  Plummer  and  of  Mr.  W.  Bell-Davies,  a  mining  engineer 
who  had  not  long  before  visited  the  field,  and  also  by  the  fact  that 
a  small  pocket  of  gold  quartz  had  a  short  time  previously  been  found 
in  the  Balaghat  mine.  Captain  Plummer  took  charge,  and  con- 
centrated his  forces  on  a  shaft  173  feet  deep,  near  very  extensive  old 
workings  at  Marikuppam.  Driving  in  a  direction  opposite  to  that 
favoured  by  most  of  his  predecessors,  he  soon  came  on  the  reef,  but 
amongst  ancient  workings.  Fortunately,  some  pillars  of  quartz 
worth  4  ounces  to  the  ton  had  been  left  in  the  old  stopes,  and  an 
effort  was  made  to  bottom  the  old  workings,  resulting  in  the  dis- 
covery of  stone  of  equal  richness.  By  the  end  of  1885  the  Mysore 
mine  had  yielded  6,099  ounces  gold,  worth  £24,000.  This  success 
naturally  galvanised  the  adjacent  companies  into  fresh  life,  and  the 
Ooregum,  Nundydroog,  and  others  found  fresh  capital.  The  general 
features  of  the  auriferous  deposits  were  now  being  recognised,  and 
from  1886  onward  the  history  of  the  field  has  been  one  of  unvaried 
success  and  prosperity.  Neither  in  mining  nor  in  milling  have  any 
serious  difficulties  presented  themselves.  The  dip  of  the  lode 
(about  55°)  greatly  facilitates  the  former,  and  since  the  gold  is  free 
milling,  the  simplest  of  methods  suffices  for  the  latter.  A  notable 
factor  in  the  reduction  of  mining  and  milling  costs  was  introduced 
in  1902.  Fuel  had  always  been  expensive,  the  necessary  coal  being 
brought  either  from  Singareni,  600  miles  distant  by  rail,  or  from 
Barakar,  400  by  rail  and  1,000  by  sea.  In  that  year  electric  power 
was  substituted  for  steam,  electricity  being  generated  at  the  Cauvery 
Falls,  92  miles  by  air-line  from  Kolar.  The  cost  at  first  was  high — 
£29  per  horse-power  per  annum — but  as  the  capital  outlay  was 
recouped  the  Mysore  Government  reduced  charges  to  £10  per 
horse-power  per  annum.  Prior  to  the  introduction  of  electricity 
the  steam  charges  had  been  £30  per  horse-power  per  annum. 

The  geology  of  the  Kolar  field  warrants  some  detailed  mention. 
Its  schist  belt  is  about  50  miles  in  length,  reaching  from  Shrinivaspur 
in  the  north,  to  four  or  five  miles  north  of  Krishnagiri  in  the  Madras 
Presidency.  The  fundamental  granite-gneiss  rocks  are  separated 
by  Dr.  Smeeth  of  the  Mysore  Geological  Survey  as  a  grey  gneiss,  an 
older  porphyritic  granite,  and  a  younger  intrusive  granite,  the  last 
being  certainly  later  than  the  schists. a  The  rocks  of  the  schist  belt 
are  also  divided  into  three    series  :    (a)  The  conglomerate    series  ; 


a  Rep.  Dep.  Mines,  Mysore,  1899. 


252 


ASIA. 


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Fig.  91.     Geological  Sketch  Map  of  the  Kolab  Goldfteld,  India  {Smeelh). 

1.  Newer  Granite.      2.  Hornblende-schist.      3.  Conglomerate  series.     4.  Older  Porphyritic  Banded 

and  Gneissose  Granite.      5.     Granitic   Gneiss.     D.  Basic   Dykes.       Q.     Ferruginous   Banded 

Quartzite. 


INDIA.  253 

(b)  hornblendic  schists  ;  and  (c)  ferruginous  quartzites.  The 
conglomerate  series  should,  perhaps,  be  named  the  pseudo- 
conglomerate  series,  since  the  structure  is  autoclastic  and  is  derived 
by  simple  crushing  and  squeezing  in  situ  of  granite  veins  in  a  horn- 
blende-schist matrix.  This  series  is  developed  along  the  eastern 
margin  of  the  belt.  The  hornblende-schist  which  makes  up  the 
greater  portion  of  the  belt  appears  to  have  originally  been  a  complex 
of  lavas  of  intermediate  or  basic  composition,  and,  as  at  Gadag, 
there  are  traces  of  original  diabasic  structure.  Though  the  beds  on 
either  side  of  the  belt  possess  dips  converging  towards  the  centre 
there  is  no  clear  evidence  of  regular  synclinal  arrangement,  and 
there  is,  indeed,  some  ground  for  the  belief  that  the  Champion  Lode 
occupies  the  position  of  a  thrust  plane  along  which  the  Dharwar 
rocks  have  overridden.     The  quartzites  are  of  the  type  already 


-  Plan  — 


Cross  Cur 

bio Level 


Fig.  92.     "Rolls"  in  Champion  Reef,  Kolar,  India  (Hatch). 

described,  and  are  developed  as  a  low  serrated  ridge  on  the  western 
side  of  the  belt.  Several  diabasic  dykes  occur,  the  largest  in  the  auri- 
ferous area  being  fairly  parallel  with  the  foliation  of  the  schist. 
Others  are,  however,  transverse  to  the  foliation. 

Several  parallel  quartz  lodes  are  known  on  the  Kolar  field,  but 
of  these  only  one,  the  Champion  Reef,  has  as  yet  proved  of  economic 
importance.  From  it,  the  gold  yield  of  the  field,  and  practically 
of  India,  is  derived.  It  carries  five  large  mines  (Mysore,  Champion 
Reef,  Ooregum,  Nundydroog,  and  Balaghat)  along  its  strike,  and 
is  payable  for  at  least  four  miles  of  its  length.  It  has  been 
followed    to    a    depth     of     3,740     feet     in     the     Mysore,    and 


254 


ASIA. 


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INDIA.  255 

3,520  feet  in  the  Ooregum  mine.  In  the  northern  end  of  the  field 
the  reef  becomes  disordered  and  no  stable  mines  have  been  developed 
beyond  the  Balaghat  ;  south  of  the  Mysore  mine  the  reef  is  also  ill- 
defined.  Its  average  width  is  perhaps  4  feet  and  its  dip  is  with  the 
foliation  of  the  enclosing  hornblendic  schists,  viz.,  about  55°  west. 
Owing  to  its  interfoliation  with  the  schists  there  is  a  tendency  to 
form  lenses  of  quartz,  but  this  feature  is  not  nearly  so  well  marked 
.as  on  most  schistose  fields.  The  walls  are,  as  a  rule,  well-defined. 
A  notable  feature  is  an  occasional  puckering  and  folding  back  of  the 
vein  on  itself  forming  in  places  great  masses  of  quartz  usually  of  high 
grade.  The  axes  of  the  folds  generally  have  a  pitch  to  the  north 
in  the  plane  of  the  vein.  This  structure  is  not  uncommon  in  quartz 
veins  in  dynamically  metamorphosed  rocks,  and  has  been  recorded, 
for  example,  from  Nova  Scotia  (p.  464)  and  from  California.  In  the 
case  of  the  Kolar  country  subsequent  mineral  reconstitution 
near  the  lode  has  largely  obliterated  the  parallel  puckerings  and 
foldings  of  the  hornblende-schist.  Two  types  of  quartz  occur,  both 
being  auriferous.  The  older  is  dark  bluish-grey,  with  a  vitreous 
lustre,  the  younger,  due  to  the  intrusion  of  diabasic  dykes,  is  white 
and  opaque.  The  gold  occurs  for  the  most  part  in  the  former,  and 
in  characteristic  shoots  that  have  a  constant  pitch  to  the  north  within 
the  vein.  The  shoots  are  generally  well  separated  by  stretches  of 
barren  or  very  low-grade  quartz,  or  by  "  pinches  "  in  the  lode-fissure 
carrying  no  quartz  at  all.  The  rich  shoot  in  the  Mysore  mine  had 
been  worked  to  a  depth  of  236  feet  by  the  ancients,  who  had  appar- 
ently grasped  the  intricacies  of  Kolar  gold-deposition.  This  great 
shoot  had  a  stoping  length  of  800  feet  with  a  maximum  width  of 
35  feet.  Its  average  width  was,  however,  about  4  feet.  It  has 
maintained  its  general  width  and  value  for  a  depth  on  its  pitch 
of  more  than  4,000  feet,  and  is  certainly  the  most  notable  shoot 
known  in  the  history  of  gold-mining.  To  1907  the  average 
tenor  of  the  ore  crushed  on  the  Kolar  field  was  more  than  an 
ounce  per  ton  over  a  quantity  of  more  than  6,000,000  tons. 

In  addition  to  gold,  the  quartz  contains  pyrite,  pyrrhotite, 
arsenopyrite,  blende,  galena,  and  chalcopyrite.  The  amount  of 
sulphides  present  is,  however,  very  small.  An  interesting  occurrence 
is  that  of  veinlets  of  tourmaline.  These  are  certainly  to  be  ascribed  to 
the  granite  intrusions,  that  as  have  already  been  seen,  are  common 
on  the  borders  of  the  schist  band.  As  might  have  been  expected, 
some  of  the  acid  intrusions  have  passed  along  favouring  fissures, 
and  occur  as  aplitic  dykes  in  the  Ooregum  mine.  The  diabasic 
dykes  of  much  later  age  have  apparently  exercised  no  appreciable 
effect  on  the  distribution  of  gold,  their  influence  being  restricted 
entirely  to  the  white  quartz  of  younger  generation. 


256 


ASIA. 


The  following  table  shows  the  yield  of  the  principal  mines  of  the 
field  from  the  commencement  of  mining  operations  to  the  end  of 
1907  :— 


Mine. 

Tonnage  Crushed. 

Crude  Ounces 
Gold. 

Value  Sterling. 

Dividends  Paid.* 

Mysore    

Champion  Reef 

Ooregum 

Nundydroog   ... 
Balaghat 

2,012,289 

1,730,448 

1,360,972 

783,730 

317,191 

2,544,108 
2,053,203 
1,212,007 

803,278 
285,050 

£9.937,542 
7,796,016 
4,537,338 
3,015,711 
1,099,194 

£5,234,288 
3,481,633 
1,501,950 
1,340,077 

227,800 

Total 

6,204,630 

6,897,646 

£26,385,801 

£11,785,748 

*  To  April  8th,  190S. 

Gadag. — Attention  was  first  directed  to  the  Gadag  field  by  the 
report  of  gold- washings  in  the  Dhoni  and  Shirhatti  streams.  The 
district  was  visited  by  Newbold  in  1 842  and  by  Aytoun  ten  years  later, 
but  the  numerous  pits  were  definitely  recognised  as  ancient  workings 
only  in  1874  by  the  veteran  Indian  geologist  Bruce  Foote,  by  whom 
the  foundation  of  our  knowledge  of  the  Dharwar  belts  has  been  laid. 
It  was,  indeed,  his  description  written  at  that  time  a  that  led  to  pros- 
pecting in  the  Gadag  district  some  26  years  later,  and  eventually  to 
the  establishment  of  the  present  mining  companies.  It  is  interesting 
to  note  here  that  the  discovery  of  all  the  ancient  mines  of  southern 
India,  with  the  exception  of  those  of  Kolar  and  the  Wainaad,  has 
been  a  direct  result  of  his  geological  work.  It  was  his  published 
description,  for  example,  that  induced  the  late  Mr.  T.  W.  Hughes- 
Hughes,  also  a  member  of  the  Geological  Survey  of  India,  to 
examine  the  Maski  band,  a  search  that  eventually  yielded  the 
dividend-paying  Hutti  mine. 

The  rocks  of  the  auriferous  portion  of  the  Gadag  band,  crossing 
from  east  to  west,  are  hornblende-schist,  chlorite-schist,  argillite, 
felsite,  and  massive  gritty  schist.  Two  main  reef  series  may  be 
made  out.  The  eastern  lies  entirely  in  a  long,  narrow  band  of 
argillite,  and  follows  a  highly  carbonaceous  band  in  the  argillite. 
The  total  length  of  the  auriferous  area  is  about  8  miles,  extending 
from  near  the  village  of  Nabapur  in  the  north,  to  the  Sangli  mines  in 
the  south.  Along  its  length  are  scattered  numerous  old  workings, 
the  majority  of  which  are  now  being  vigorously  prospected.  The 
reefs  are  permanent,  but  vary  locally  both  in  width  and  in  value. 
They  show  the  lenticular,  en  echelon  structure  characteristic  of 
veins  in  schistose  rocks.  The  quartz  is  typically  associated  with 
graphitic  '  pug,"  the  graphite  being  obviously  derived  from  the 
enclosing  carbonaceous  argillite.  Pyrite  is  naturally  abundant  in  the 


"Rec.  Geol.  Surv.  India,  XXI,  1SS6,  p.  40. 


Plate   VII. 


Dharwar  Schists,  Saxgli.  Ixdia. 


% 


INDIA. 


257 


country  of  the  veins.  The  principal  mine  on  the  band  is  the  Dhar- 
war  Reefs,  near  Kabligatti  village.  It  has  reached  a  depth  of  940 
feet,  bottoming  the  ancient  workings  at  250  feet.  It  is  the  only 
producing  company  on  the  field,  commencing  crushing  with  a 
20-stamp  mill  in  February,  1907.  From  that  month  to  April, 
1908,  it  had  crushed  for  the  fifteen  months  15,739  tons  ore  for  a 
yield  of  7,302  crude  ounces,  worth  about  £27,700.  The  tailings,  which 
were  still  to  be  treated,  contained  about  4  dwts.  gold  per  ton.  The 
other  mines  on  the  belt,  including  those  of  Sangli,  are  still  in  the 
prospecting  stage. 

Four  miles  west  of  the  foregoing  is  the  Hosur  series  of  reefs. 
So  far  as  may  be  made  out,  for  the  surface  is  largely  covered  with 


a  Banded  Quarttte  *  Quarts  flwphun|. 

9    Mass.c  Cfttty  &HsS    3   Hornblende- SchiiT. 
a  Arjjlllite.  z.  Diabase-Schist. 

J.  Conglomerate.         I.  Granite-Gneiss 

•.-Old  Worklnjp. 


Fig.  94.     Geology  of  the  Neighboukhood  of  the  Gadag  Mines.  India. 


cotton  soil,  these  lie  in  chlorite-schist  and  massive  gritty  schist  near 
felsite.  These  mines  carry  no  graphite,  and  are  still  in  the  development 
stage.  Hornblende-schists  similar  to  those  of  Kolar  occur  on  the 
eastern  side  of  the  belt,  but  are  not  known  to  carry  auriferous 
veins. 

Hutti. — The  Hutti  mine  lies  within  the  boundaries  of  the 
Maski  band,  as  first  described  by  Foote.  This  schist  belt  lies  south 
of  the  Kristna  river  in  the  Lingsugur  division  of  the  Nizam's 
Dominions.  Its  auriferous  veins  were  discovered  by  Mr.  T.  W. 
Hughes-Hughes  in  1887,  his  search,  as  already  mentioned,  being 
based  on  Bruce  Foote's  geological  work.  In  1887  the  rights  to  the 
minerals  within  the  Hyderabad  State  were  bought  by  the  Hyderabad 
(Deccan)  Company.     From  first  to  last,   this  company,  together 


R 


258  Asia. 

with  a  subsidiary  company  (Wondalli),  expended  some  £400,000 
on  gold-mining  in  the  district.  Numerous  ancient  workings  were 
discovered  and  a  few  were  opened  up.  The  Wondalli  veins  a  few 
miles  from  Hutti  were  taken  over  and  operated  by  the  above- 
mentioned  subsidiary  company  and  gold  to  the  value  of  £60,000  was 
won,  all  of  which  went  back  into  the  mine.  No  profit  was  made, 
and  the  company  ceased  operations  in  1900.  Its  most  productive 
year  had  been  1899,  when  18,970  tons  were  crushed  for  a  yield  of 
7,822  ounces.  The  whole  history  of  gold-mining  by  these  com- 
panies was  characterised  by  extravagance  and  general  disregard  of 
mining  economics.  A  mine  opened  at  Boodinnie,  south  of  Wondalli, 
was  worked  long  after  it  should  have  been  obvious  that  the  stone 
obtained  was  too  poor  to  pay  even  milling  expenses.  The  quartz 
was  nevertheless  crushed. 

The  bright  page  in  the  history  of  the  field  was  opened  with  the 
formation  of  the  Hutti  company  with  a  capital  of  £55,000.  Mining 
at  Hutti  commenced  in  1901,  and  crushing  in  February  of  1903. 
Its  career  has  been  uniformly  successful.  To  the  end  of  1907  the 
30-head  mill  had  crushed  104,065  tons  quartz  for  56,894  crude 
ounces  worth  £216,927,  and  had  paid  dividends  of  £29,902  and 
royalties  of  £11,000.  It  will,  from  the  foregoing  figures,  be 
obvious  that,  considering  the  high  mining  costs  due  to  the 
distance  (45  miles)  of  the  mine  from  the  nearest  railway  station 
(Raichur),  the  quartz  must  be  regarded  as  low-grade.  All  fuel 
and  mine-supplies  are  carried  by  bullock-cart  over  ill-made  sandy 
and  stony  roads. 

At  Hutti  the  deepest  modern  workings  have  reached  1,440  feet. 
The  ancient  workings  were  finally  bottomed  at  620  feet. 

Of  late  years  several  prospecting  companies  have  been  formed 
to  work  neighbouring  veins  at  Topuldodi,  south-east  of  Wondalli, 
and  in  the  Shorapur  district  across  the  Kristna  river,  but  in  no  case 
have  the  results  obtained  been  sufficiently  encouraging  to  warrant 
the  formation  of  mining  companies  with  large  capitals,  and 
prospecting  has  now  practically  ceased. 

The  Maski  band  of  Dharwar  schists  in  which  the  Hutti  mine 
lies,  is  some  7  to  8  miles  in  width,  and  stretches  in  an  approximately 
meridional  direction  for  about  45  miles  across  the  Raichur  Doab. 
The  chief  members  of  the  schistose  series  are  hornblende- 
schist,  altered  diabase,  chlorite-schist,  and  acid  schistose  rocks,  the 
last  possibly  representing  altered  porphyries.  The  whole  complex 
is  crossed  by  younger  diabasic  dykes,  while  along  the  northern 
boundary  the  schists  have  been  attacked  by  granite  intrusions. 
Along  the  eastern  border  of  the  belt  are  pebbly  conglomerates  and 
other  original  sedimentary  members. 


INDIA.  259 

The  veins  of  the  Hutti,  Topuldodi,  and  Wondalli  mines  are  in  a 
hornblende-schist  precisely  similar  to  that  of  the  Kolar  field.  The 
Boodinnie  vein  lay,  however,  in  a  soft  chlorite-schist.  The  Hutti 
vein,  the  only  one  of  present  importance,  lies  near  the  western  border 
of  the  belt  and  strikes  parallel  with  the  line  of  contact  of  granite 
and  schist.  In  it  vein-quartz  of  both  older  and  younger  generation 
are  found,  the  older  dark  chalcedonic  bluish-grey  variety  being 
auriferous,  the  younger  white  form  poor  or  barren.  The  last  is 
especially  abundant  near  a  diabase  dyke  crossing  the  north-west  end 
of  the  Hutti  lode-channel.  The  vein  conforms  with  the  schistosity 
of  the  country,  dipping  at  a  high  angle  to  the  west.  The  quartz  is 
disposed  in  lenses  of  an  average  diameter  of  perhaps  100  feet,  and 
a  maximum  thickness  of  5  feet.  Their  edges  overlap  en  echelon, 
both  laterally  and  vertically.  The  ore,  therefore,  lies  rather  in  a 
lode-channel  than  in  a  continuous  quartz  vein. 

Anantapur. — The  schist  belt  in  which  the  Anantapur  mines 
are  situated  was  discovered  by  Mr.  E.  W.  Wetherell,  of  the  Mysore 
Geological  Survey  in  March,  1902.  It  lies  in  the  Madras  Presidency 
about  9  miles  from  Nagasamudram  station  on  the  Southern  Mahratta 
railway.  Prospecting  here  was  commenced  in  April,  1906.  Old 
workings  are  fairly  numerous  on  the  three  main  reefs  of  the  central 
portion.  So  far  as  is  yet  known,  the  ancients  do  not  appear  to  have 
reached  a  greater  depth  than  118  feet. 

Tumkur. — The  Bellara  and  Bodimardi  veins,  in  the  Gadag- 
Seringapatam  belt  near  Chitaldroog,  lie  either  in  diabase  or  in  a 
chloritic-schist  with  which  are  associated  argillaceous  and 
ferruginous  schists  and  some  limestones  and  conglomerates.  The 
quartz  is  generally  small  and  of  low-grade,  but  may  rise  in  width 
to  3 \  feet,  with  a  value  of  \  to  \\  ounces  per  ton.  Numerous  old 
workings  have  been  prospected  in  this  neighbourhood,  but  none  have 
yielded  a  mine,  though  a  depth  of  380  feet  was  reached  in  the 
Bellara  property. 

Coimbatore. — Numerous  old  native  workings  for  gold  occur  in 
the  Kollegal  and  Satyamangalam  taluks  of  the  Coimbatore  district ; 
but  the  veins  are  small  and  unimportant.  Considerable  unsuccessful 
prospecting  work  has  been  carried  on  at  the  Haddabanatta  and 
Bensibetta.  The  rock  in  which  the  veins  lie  is  schistose,  and  is 
probably  to  be  correlated  with  the  Dharwars. 

Wainaad. — This  field  demands  mention  rather  from  its  past 
history  than  for  the  value  of  its  gold-quartz  veins.  It  lies  to  the 
west-north-west  of  Ootacamund  on  the  slopes  of  the  Western 
Ghauts.  Its  gold  veins  and  the  alluvial  deposits  derived  therefrom 
have  been  worked  for  many  centuries  by  native  methods.     They 


260  ASIA. 

appear  to  have  attracted  the  attention  of  Europeans  about  179.3,, 
and  from  thence  to  1865  they  were  the  subject  of  various  recommen- 
dations and  reports.  During  the  earlier  years  of  the  nineteenth 
century  they  had  been  worked  by  slave  labour.  With  the  abolition 
of  slavery  and  the  demand  for  labour  on  the  coffee  plantations  of  the 
vicinity,  work  in  the  mines  ceased  almost  completely.  In  1 865  the 
field  was  visited  by  Australian  miners,  and  a  little  prospecting,  result- 
ing in  the  erection  of  a  quartz-mill,  undertaken  on  the  gold-quartz 
veins.  These  early  explorations  met  with  little  or  no  success. 
Nevertheless,  from  1879-81,  the  field  was  the  scene  of  one  of  the  most 
extraordinary  "booms"  of  modern  history.  Numerous  companies, 
with  an  aggregate  capital  of  no  less  than  four  millions  sterling, 
were  called  into  existence.  The  proportion  of  the  subscribed  capital 
that  did  not  go  into  the  pockets  of  promoters  was  squandered  mainly 
in  expensive  and  useless  machinery,  little  of  which  was  put  into 
actual  operation.  Theslumpthat  followed  the  "boom  "  was  complete. 
From  time  to  time,  however,  efforts  have  been  made  to  reopen  some 
of  the  mines,  but  these  have  met  with  little  success.  Expert  exam- 
ination has  shown  that  the  veins  are  low-grade,  but  occasionally 
carry  rich  pockets,  too  small  to  exercise  any  notable  effect  on 
the  general  tenor  of  the  quartz,  but  sufficient  often  to  raise  futile 
hopes  in  the  breasts  of  shareholders.  An  extended  examination  of 
the  better-known  veins  was  made  in  1900  by  Dr.  Hatch  and 
Mr.  Hay  den,  of  the  Indian  Geological  Survey,  with  disappointing 
results.  The  general  average  of  numerous  samples  was  only  2  dwts. 
per  ton  over  a  width  of  5  •  4  feet." 

The  country  of  the  veins  is  biotite-gneiss,  which,  together  with 
other  metamorphic  types,  occurs  with  dubious  Dharwarian  rocks,  all 
being  penetrated  by  basic  and  acid  intrusives.  The  veins  run 
obliquely  to  the  foliation  of  the  gneiss,  and  are  occasionally  of 
considerable  width.  They  are  often  pyritous,  furnishing  pyrite, 
marcasite,  mispickel,  &c.  The  pyrite  is  the  chief  source  of  the 
auriferous  values ;  and  the  free  gold  occurring  is  derived  from  its 
decomposition.  The  figures  of  the  crushings  in  bulk  uniformly 
bear  evidence  of  the  low  grade  of  the  veins.  Thus  up  to  the  beginning 
of  1883,  some  3,597  tons  had  been  crushed  for  a  yield  of  only  482 
ounces,  or  nearly  2  •  7  dwts.  per  ton. 

Elsewhere  in  India,  vein  mining  has  been  carried  on  far  to  the 
north  of  the  Dharwar  belts  shown  in  the  accompanying  map.  The 
chief  district  was  at  Sonapet  in  Bengal,  in  the  Chota  Nagpur  Dharwar 
schist  area.  This  was  the  scene  of  a  notable  "boom"  in  1891-2,  that 
caused  considerable,  but  unfortunately  unjustifiable,  excitement  in 
Calcutta.  Only  a  few  ounces  of  gold  were  obtained  from  the  principal 

°  Mem.  Geol.  Sixty.  India,  XXXIII,  1902,  p.  30. 


INDIA.  261 

mine,  and  it  is  doubtful  whether  even  these  few  were  the  natural 
product  of  the  mines.  Despite  the  lack  of  gold,  companies  with  an 
aggregate  capital  of  a  million  sterling  were  formed.  In  this  district 
gold-quartz  veins  will  probably  yet  be  discovered  near  Raigara,  in 
the  jungles  west  of  Chakhardhapur,  on  the  Bengal-Nagpur  railway, 
since  numerous  crushing  and  rubbing  stones  have  been  found  there, 
recalling  those  known  from  the  outcrops  of  the  gold-quartz  veins  of 
southern  India.  Occasional  small  patches  of  gold,  generally  asso- 
ciated with  galena  in  cavities  in  a  porous  quartz,  have  indeed  been 
found  in  the  Chota  Nagpur  area.  Of  these,  the  largest  was  at  Pahar- 
diah,  near  Manharpur.  It  yielded  a  few  pounds  only  of  very  rich 
"  specimen  "  stone,  plentifully  bespattered  with  gold. 

Alluvial  Gold. — In  few  countries  is  alluvial  gold  more  widely 
distributed,  and  in  few  countries  also  does  it  show  less  tendency  to 
aggregation  under  the  influence  of  running  water.  Regarded  as 
a  whole,  the  seasons  of  India  may,  from  the  alluvial  miner's  point 
of  view,  be  divided  into  dry  and  wet.  The  duration  of  the  latter 
is  about  four  months,  and  nearly  the  whole  of  an  abundant  rain- 
fall takes  place  in  that  time.  In  consequence,  the  rivers  are,  during 
the  monsoon,  raging  floods  that  change  their  direction  across  their 
flood  plains  from  day  to  day.  The  gravel  deposit  of  one  day  is 
therefore  either  broken  up  and  its  gold  widely  dispersed  by 
the  flood  of  the  next  week,  or  it  is  covered  by  the  next  flood 
with  many  feet  of  fine  sand.  The  only  concentration  possible 
under  these  conditions  is  that  of  the  flaky  flood-gold  which, 
as  the  river  is  falling,  is  caught  in  the  natural  riffles  provided 
by  the  stony  gravel  bars  and  beaches  formed  at  the  head  or 
at  the  tail  of  an  island,  at  the  lower  end  of  a  long  pool,  or  on 
the  convex  curve  of  an  ox-bow  in  the  river.  The  deposition  of  gold 
on  a  bottom  is  generally  impossible.  On  the  other  hand,  in  the  cen- 
tral Deccan,  where  auriferous  schist  belts  occur,  the  rainfall  is  too 
slight  (below  20  inches),  under  the  tropical  conditions  prevailing, 
to  permit  of  aqueous  concentration  of  gold  in  quantity  ;  further, 
the  change  from  regions  of  low  rainfall  to  those  of  high  monsoon  fall 
is  confined  to  bands  of  only  a  few  miles  in  width,  parallel  to  the 
coast,  and  situated  at  the  edge  of  the  Ghauts. 

Alluvial  gold  is,  nevertheless,  found  in  minute  quantities 
wherever  streams  drain  areas  of  the  old  schist  rock,  and  wherever 
they  at  the  same  time  have  a  grade  suitable  for  the  carriage  and 
deposition  of  gravel.  Such  conditions  obtain  in  many  streams  in 
Mysore,  Madras,  Bombay,  Hyderabad,  Central  India,  and  Chota 
Nagpur,  but  in  no  case,  so  far  as  is  yet  known,  are  the  gravels  suffi- 
ciently rich  to  warrant  European  examination,  though  in  many 
places  they  afford  a  few  weeks'  employment  during  the  cold  weather 


2G2  asia. 

to  the  native  washer,  who  is  content  to  work  for  a  return  of  ljd.  to 
2d.  per  day.  In  the  west  of  Chota  Nagpur  a  few  men  are  em- 
ployed at  gold-washing  all  the  year  round,  but  ordinarily  they  com- 
bine with  the  pursuit  of  gold-washing,  one  or  more  of  the  more  menial 
occupations  of  the  Indian  village.  Where  the  gravels  are  very  poor, 
the  work  of  washing  is  left  entirely  to  women  and  children.  A  very 
small  quantity  of  gold  is  thus  annually  obtained,  and  seeing  that 
climatic  conditions  have  not  varied  greatly  during  the  historial  cen- 
turies, it  is  exceedingly  improbable  that  the  yield  of  alluvial  gold  in 
India  was  ever  extensive. 

From  a  metalliferous  point  of  view  the  Himalayas  are  singularly 
barren.  There  has  never  been  manifested  in  this  uplift  that  extru- 
sion of  igneous  magmas  of  which  metalliferous  impregnation  appears 
to  be  an  inevitable  concomitant.  The  streams  flowing  from  and 
through  this  great  range  are  therefore  as  a  rule  devoid  of  gold. 
Above  Attock,  and  in  the  upper  waters  of  the  Indus,  and  in  the 
Alakananda  are  small  gravel  banks  that  are  even  now  worked.  Much 
of  this  gold  is  probably  derived  from  the  Tibetan  plateau,  since  many 
of  the  Indo-Gangetic  streams  have  pushed  through  the  main  range 
and  captured  some  of  the  drainage  channels  of  that  region.  In 
Upper  Assam  also,  streams  that  flow  from  the  north  into  the 
Brahmaputra,  as  the  Subansiri,  carry  small  quantities  of  gold.  One 
small  bar  near  the  mouth  of  the  Subansiri  gorge  yielded  on  examina- 
tion at  the  rate  of  more  than  a  pennyweight  per  cubic  yard.  The 
quantity  of  gravel  available  was,  however,  very  small.  It  is  probable, 
also,  that  some  of  the  gold  of  this  region  is  derived  by  a  re-wash  of 
the  Tipam  (Siwalik)  sandstone  that  wraps  round  the  Brahmaputra 
Valley,  both  on  the  north  and  on  the  south.  For  the  gold  of 
the  Lohit  (or  sacred)  branch  of  the  Brahmaputra,  a  source  must 
be  sought  in  the  metamorphic  rocks  of  Miju  ranges  in  the  head- 
waters of  that  river.a 

The  methods  of  the  native  washers  of  India  are  extremely 
primitive.  Their  implements  are  the  wooden  batea  or  a  short 
inclined  trough,  with  rude  sieves  and  scrapers.  In  the  use  of  these 
they  are,  however,  extremely  expert,  since  they  have  had  always 
to  deal  with  flaky  flood  gold  that  necessitates  extreme  care  in  its 
use.  Like  native  washers  in  Sumatra  and  in  Colombia,  the  Kols  of 
Chota  Nagpur  use  the  soapy  juice  of  the  leaves  of  a  tree  (in  this  case 
a  creeper,  Combretum  decandrum)  to  facilitate  the  separation  of  the 
fine  gold  from  the  associated  black  sand  left  behind  in  the  batea  as 
the  last  residue  on  washing. h 

1  Maclaren,   "  Auriferous  Occurrences  of  Upper  Assam,"   Rec.  Geo!.   Surv.   India, 
XXXI,  1904,  p.  179. 

b  Maclaren,  lb.,  XXXI,  1904,  p.  66. 


INDIA. 


263 


The  total  gold  yield  of  India  during  the  present    century  is 
shown  in  the  attached  table  : — 


Year. 

Crude  Ounces. 

Value,  Sterling. 

1901 

531,766 

£1,930,737 

1902 

517,639 

1,970,230 

1903 

603,787 

2,303,144 

1904 

618,746 

2,366,079 

1905 

630,817 

2,416,966 

1906 

581,545 

2,230,284 

CEYLON. 


The  existence  of  alluvial  gold  in  Ceylon  has  been  known  for  many 
years.  Search  was  made  for  it  under  the  direction  of  Sir  Samuel 
Baker  in  1854,  and  by  others  in  later  years.  In  1902-3  Mr.  C.  G. 
Dixon  reported  it  to  be  widely  distributed  in  small  quantities  in  the 
central,  western,  and  southern  portions  of  the  island.  Dr.  A.  K. 
Coomara-Swamy  in  1905  directed  prospecting  operations,  finding  a 
little  gold  at  Niriella,  Weralupe,  Marapona,  and  Dombagammana  in 
the  Kalu-ganga,  or  in  the  We-ganga,  its  principal  tributary.  These 
localities  lie  about  40  miles  east-south-east  of  Colombo.  Gold  also 
occurs  in  the  head- waters  of  the  Welawe-ganga,  especially  near 
Balangoda,  about  60  miles  from  Colombo  in  the  same  direction  as 
the  foregoing.  Other  localities  at  which  gold  is  occasionally  met 
with  in  the  search  for  gems  are  the  Pellawatta-ganga  and  the 
Moon  Plains,  near  Nuwara  Eliya.a  In  no  case  was  gold  found  in 
sufficient  quantity  to  warrant  dredging.  The  grains  obtained  were 
exceedingly  fine,  the  largest  in  the  possession  of  the  Ceylon  Minera- 
logical  Survey  coming  from  Balangoda,  and  weighing  no  more  than 
6-4  grains  ( -415  gramme).  Native  washers  work  the  gravels  by  a 
rude  method  of  stream  sluicing,  finishing  the  concentration  in  a 
wooden  batea,  or  even  in  a  cocoa-nut  shell.  The  gold  would  appear 
to  be  derived  from  the  ancient  metamorphic  rocks  of  the  island. 


BURMA.& 

Burma  has  long  enjoyed  the  reputation  of  possessing  rich  and 
extensive  auriferous  deposits.  It  formed  the  northern  portion  of  the 
Chryse  of  Pomponius  Mela — the  Golden  Chersonese  of  Ptolemy. 
As  such  there  was  written  across  it  on  mediaeval  maps,  "  Here  is 
much  gold  " — that  alluring  legend  attached  to  so  many  far  eastern 
and  little  known  countries.     In  recent  years  the  pan  and  the  assay 

u  Ceylon  Administration  Reports,  1905,  Mineralogical  Survey,  E.  5. 
b  Maclaren,  Min.  Jour.,  LXXXII,  1907,  p.  113. 


264 


ASIA. 


balance  of  the  prospector  have  gone  far  towards  dispelling  the  time- 
honoured  illusion.  Nevertheless,  gold  is  widely  distributed  through- 
out Upper  Burma  and  those  parts  of  Lower  Burma  immediately 
adjacent  to  the  mountain  ranges.  Few  gold-quartz  veins  have  been 
brought  to  light.  Those  discovered  lie  either  in  the  Tertiary  andesitic 
country  between  Wuntho  and  Banmauk  in  Upper  Burma,  or  in  the 
gneissic  ranges  south  of  Nam-Kham  on  the  Shweli  river. 


^ 


Sketch  Map 

of 

BURMA 


-8f 


<x.W 


Fig.  95.     Distribution  or  Gold  in  Burma. 


The  Choukpazat  (Kyoukpazat)  veins  have  furnished  the  only 
gold  mines  yet  worked  in  Burma.  They  lie  26  miles  north  of  Wuntho 
and  11  miles  from  Nankan,  the  nearest  railway  station.  The  region 
is  covered  with  dense  jungle,  and  its  rocks  are  overlain  by  a  heavy 
soil-cap  that,  together  with  the  jungle,  renders  geological  exploration 
most  difficult.  The  rocks  are  consolidated  and  fairly  well  stratified 
tuffs  and  breccias  of  andesitic  facies,  intruded  in  places  by  quartz- 


BURMA. 


265 


diorites.^  Veins  similar  to  those  at  Choukpazat  occur  at  and  near 
Legyin,  11  miles  further  north,  and  also  in  the  neighbourhood  of 
Banmauk.  The  Choukpazat  veins  were  discovered  by  Kadu  Shan 
washers  when  following  up  auriferous  shoadings,  and  were  worked  by 
them  to  a  depth  of  8  to  10  feet.  They  attracted  European  capital  in 
1894,  and  were  developed  for  a  couple  of  years  with  results  suffi- 
ciently encouraging  to  warrant  the  erection  of  a  light  750-lb.  10- 
stamp  mill,  to  which  a  cyanide  plant  was  eventually  added.  Work 
was  vigorously  and  efficiently  carried  on  until  1903,  when  the 
auriferous  shoot,  upon  which  mining  had  been  concentrated, 
pinched  out.  After  considerable  exploratory  work,  unfortunately 
fruitless,  the  mine  was  abandoned  and  the  machinery  dismantled. 
It  is  difficult  to  obtain  accurate  figures  relating  to  the  Choukpazat 
output,  since  they  seem  not  to  have  been  preserved  in  the  records  of 
the  Indian  Mines  Department,  and,  moreover,  where  they  have  been 
supplied  by  the  company  they  refer  often  to  a  financial  year  ter- 
minating differently  from  that  officially  adopted.  The  following 
figures  are  probably  as  close  an  approximation  to  the  truth  as  is 
now  possible  : — 


*  October  to  March  31st  only. 

The  total  output  Avas  therefore  presumably  a  little  more  than 
8,000  ounces,  of  a  value  of,  say,  £31,000.  The  highest  yield  was 
obtained  during  1902,  when  1,984  ounces,  valued  at  £7,606,  were 
produced.  The  average  gold  per  ton  for  the  seven  years  available 
is  8-3  dwts. 

Generally  speaking,  the  veins  of  this  andesitic  region  are  highly 
pyritic  and  low  grade.  The  Choukpazat  vein  was  proved  to  a 
depth  of  420  feet,  but  the  valuable  portion  appears  to  have  been 
above  the  310-feet  level.  The  length  of  the  ore  body  was  about 
240  feet,  the  vein  being  cut  off  to  the  south-west  by  an   intrusive 

a  Gen.  Rep.  Geol.  Surv.  India,  1899-1900,  p.  63. 


266  asia. 

dyke.  On  the  north-west  it  pinched  out  in  the  country.  Its  thick- 
ness varied  from  2  inches  to  10  feet,  with  an  average  of  3  feet 
6  inches.  Below  the  310-feet  level  the  quartz  was  associated  with 
calcite.  It  was  occasionally  clean,  but  more  often  was  well  mineralised, 
carrying  5  per  cent,  of  chalcopyrite,  pyrite,  galena,  and  franklinite 
(oxide  of  iron,  manganese,  and  zinc).  The  last,  when  separated, 
contained  as  much  as  7  ounces  of  gold  per  ton  of  concentrate,  the 
copper  and  iron  pyrites  from  2  grains  to  18  dwts.  per  ton,  while  the 
galena  carried  nothing.  An  excellent  indicator  for  gold  was  altaite, 
the  somewhat  rare  telluride  of  lead.a  Most  of  the  gold  was  extremely 
fine.  The  bullion  from  the  plates  averaged  850  gold.  Total  costs 
were  about  14s.  per  ton,  labour  being  cheap  and  fairly  efficient. 
The  only  other  gold-quartz  veins  reported  from  Burma  are  those 
in  the  gneissic  range  lying  south  of  the  Shweli  river  in  the  Northern 
Shan  States.  These  veins  are  large  and  heavily  mineralised,  but 
of  very  low  grade. 

Taking  the  great  Irawadi  river  first,  as  its  importance  naturally 
warrants,  poor-gold  gravels  occur  near  Prome  and  at  Shwedaung, 
where  desultory  washing  has  long  been  carried  on.  The  next 
auriferous  occurrence  is  400  miles  farther  up  the  river  at  Shwegu. 
In  the  Mozit  Chaung,  near  the  mouth  of  the  Second  Defile,  the 
fine  gravels  appear  to  be  faintly  auriferous.  From  Sinbo,  at  the 
upper  entrance  to  the  Third  Defile  to  the  confluence  of  the  Irawadi 
is  a  distance  of  about  100  miles.  This  stretch  of  river  is  held  by 
the  Burma  Gold  Dredging  Company,  with  head-quarters  at  the 
riverside  station  of  Myitkyina,  the  British  administrative  post 
farthest  up  the  Irawadi.  The  history  of  the  company  dates  back 
to  1900,  when  the  question  of  the  practicability  of  dredging  the 
Irawadi  gravels  was  first  taken  up.  Vigorous  prospecting  during  the 
season  of  1900-1  showed  that  dredging  was  feasible,  and  in 
1902  a  small  dredge,  bought  and  dismantled  in  New  Zealand,  was 
re-erected  at  Myitkyina.  In  October  of  that  year  dredging 
operations  were  commenced.  The  dredge  was  small  and,  being 
square-ended,  not  altogether  suited  to  the  conditions  obtaining  on  the 
Irawadi.  Nevertheless,  it  did  most  useful  prospecting  work  until 
March,  1904,  when  a  sudden  rise  in  the  river  brought  down  so  much 
floating  debris  to  be  piled  against  the  dredge  and  head-line  that  the 
latter  parted  and  the  dredge  was  capsized  and  lost.  It  had  during 
its  prospecting  career  recovered  441  -69  ounces  of  gold,  of  a  value 
of  £1,680.  5s.  Three  large  dredges  were  at  work  on  the  concession  in 
1907.  They  are  fitted  with  the  abnormally  powerful  winches  necessi- 
tated by  the  great  length  of  head-  and  side-lines,  the  width  of  the 
river  occasionally  requiring  as  much  as  300  yards  of  the  latter,  with 

a  Louis,  H.,  Trans.  N.  Eng.  Inst.  M.E.,  XLVI,  1897,  p.  129. 


BURMA. 


267 


a  correspondingly  long  head-line.  The  banks  of  the  river  are  low, 
and  there  is  therefore  no  possibility  under  ordinary  conditions  of 
keeping  the  lines  clear  of  the  water.  Every  rise  of  the  river  brings 
down  great  quantities  of  floating  timber,  constituting  one  of  the 
chief  obstacles  to  dredging  when  the  rainy  season  is  approaching. 
Dredging  time  is  largely  broken  by  the  "  rains,"  and  may  be 
reckoned  at  eight  months  in  the  year.  The  "  wash  "  itself  is  coarse 
gravel,  with  the  gold  fairly  well  disseminated  throughout.  There  is 
therefore  little  or  no  stripping.  Its  treatment  when  raised  presents  no 
technical  difficulties.  Small  quantities  of  platinum  and  platinoid 
metals  are  recovered  with  the  gold.  The  returns  of  the  company 
are  private,  those  available  from  official  sources  being  as 
follows  : — 


Ounces. 

Value. 

1903 
1904 
1905 
1906 

370-05 

214-30 

621-00 

2,30100 

£  s.  d. 
1,401      6      7 

826  16  4 
2,418  10  8 
8,855     6     8 

3,506-35 

13,502     0     3 

The  Mole  Chaung,  after  meandering  across  the  old  flood-plain 
of  the  Irawadi,  joins  that  river  a  little  above  Bhamo.  At  its 
debouchure  from  the  hills  near  Nalon  gravels  were  found  which  were 
for  a  time  considered  to  promise  payable  results.  They  have  since 
been  thoroughly  prospected  with  a  Keystone  drill,  and  are  now 
considered  to  be  valueless.  The  Nalon  gravels  are  possibly  a  re- wash 
of  ancient  high-level  Irawadi  gravels,  the  great  river  having  flowed 
here  under  the  Chinese  frontier  hills  before  it  forsook  its  broad  flood- 
plain  to  flow  through  the  narrow  Third  Defile.  A  little  desultory 
washing  of  no  importance  is  carried  on  near  Myothit  on  the  Taiping 
river  east  of  Bhamo. 

The  great  western  tributary  of  the  Irawadi,  the  Chindwin, 
carries  a  little  gold  wherever  gravels  occur  along  its  course.  In 
one  spot  alone — viz.,  Helaw,  are  the  gravels  sufficiently  rich  to 
attract  more  than  passing  attention  from  even  the  native 
washer,  who  is,  in  Burma,  generally  a  woman.  Near  Helaw 
the  Chindwin  widens,  and  its  waters,  on  a  low  river,  divide 
to  form  a  long  gravel  island.  The  island  is  swept  by 
the  great  floods  of  the  rainy  season,  and  the  sand  carried  away, 
exposing  the  larger  stones  that  then  act  as  an  excellent 
natural  riffle-bed  in  which  the  gold  is  caught.  As  the  waters  subside 
and  uncover  the  head  of  the  island,  the  Burmese  washers  attack  the 
gravel  exposed,  taking  only  the  surface  covering  to  a  depth  of  about  a 


268  .  asia. 

foot.  During  most  seasons  the  results  are  poor,  even  from  a  native 
point  of  view,  but  occasionally  a  lucky  concentration  takes  place. 
The  apparatus  of  the  native  washer  is  extremely  simple,  consisting 
only  of  a  shallow  wooden  sluice-box  in  which  rough  concentration 
is  effected,  and  a  wooden  batea  in  which  the  gold  is  finally  separated 
from  the  black  sand.  The  average  earnings  of  the  washers  are 
probably  less  than  four  annas  (fourpence)  per  day. 

A  concession  of  that  portion  of  the  Chindwin  lying  between 
Minsin  and  Homalin — about  1 80  miles — was  granted  to  the  Manda- 
lay  Dredging  Company.  After  some  preliminary  prospecting  a 
dredge  was  obtained,  erected  at  Rangoon,  towed  up  the  Irawadi  to 
Pakokku,  and  thence  up  the  Chindwin  to  Maukkadaw,  where  it  was 
unfortunately  stranded.  Before  it  could  be  refloated  the  company 
had  gone  into  liquidation,  and  the  dredge  was  eventually  sold  to  be 
dismantled  to  go  to  South  America.  The  Chindwin  gravels,  there- 
fore, remain  virgin  ground. 

The  Upper  Chindwin,  from  Homalin  to  Manbin,  130  miles  farther 
up,  has  been  examined  from  time  to  time  by  various  prospecting 
parties,  but,  since  no  concessions  have  been  applied  for  after  pro- 
specting, it  has  apparently  been  considered  valueless. 

At  Kyobin,  on  the  Uyu  river,  a  tributary  falling  into  the 
Chindwin  below  Homalin,  old  high-level,  false-bedded,  auriferous 
gravels  occur.  These  have  for  some  generations  been  worked  by  the 
Burmese  by  a  rude  method  of  ground-sluicing.  They  also  have 
attracted  the  attention  of  prospectors,  but,  since  no  serious  work 
has  been  done  on  them,  are  presumably  too  low  in  value  to  return 
interest  on  the  capital  necessary.  The  gold  of  these  gravels  is 
brought  from  the  south  to  its  present  position  by  the  Chaungyi 
Chaung.  This  stream  drains  the  andesitic  country  from  Banmauk 
to  near  Choukpazat,  and  its  gold  is  derived  from  the  degradation 
of  the  small  pyritic  gold-quartz  veins  already  described  as  occurring 
in  that  area.  The  higher  reaches  of  the  Uyu  as  far  as  the  military 
outpost  of  Hoang-pa  have  also  been  prospected,  but  with  little 
success.  The  Chindwin  and  its  tributaries  have,  therefore,  during  the 
past  five  years,  been  fairly  closely  examined,  and  have,  on  the  whole, 
been  considered  too  poor  for  further  exploitation.  Natives  still 
wash  along  the  Chaungyi  Chaung  :  at  Kyobin  :  and  at  Leiksaw, 
but  their  earnings  are  in  all  cases  certainly  small. 

In  the  Northern  Shan  States,  on  the  eastern  frontier  of  Burma, 
there  occur  numerous  short,  narrow,  but  deep  valleys  opening  into 
the  Salween  gorges.  Some  of  these  carry  auriferous  gravels.  The 
Nam-Hsawm,  one  of  the  longest  on  the  right  bank  of  the  Salween, 
was  in  former  days  worked  by  Chinese,  and  was  taken  up  in  1905 
by   the    Namma   Gold   Dredging    Company,    with    capital    raised 


BURMA.  269 

mainly  in  Rangoon.  After  preliminary  exploration  the  gravels 
were  considered  sufficiently  rich  to  warrant  the  erection  of  a  dredge 
on  the  ground,  an  end  effected  only  after  overcoming  numerous 
difficulties,  of  which  the  formation  of  a  road  40  miles  long  to  enable 
the  machinery  to  be  placed  on  the  ground  was  by  no  means  the  least. 
After  a  short  run  it  was  found  that  the  value  of  the  gravel  had  been 
over-estimated,  and  the  dredge  was  abandoned.  It  was,  in 
1908,  being  worked  by  Chinese.  South  of  Namma,  near  the 
Loi-Twang  mountain,  are  native  gold  washings.  These  have 
been  exhaustively  investigated  by  the  Geological  Survey  of 
India,"  and  have  been  proved  to  be  of  no  commercial  value.  Accord- 
ing to  the  Burmese  and  the  Shans,  the  streams  of  the  Wa  country 
across  the  Salween  opposite  Namma  are  highly  auriferous.  More 
particularly  is  this  so  in  the  case  of  the  Shwe-Thamin-Chaung  (the 
Stream  of  the  Golden  Deer).  Yet  the  only  expedition  that  has 
entered  this  country  failed  to  find  gold  in  this  valley.  It  is  true, 
however,  that  the  expedition  halted  only  for  two  or  three  hours  at 
the  stream,  and  that  it  had  no  gold-washers  with  it.  In  the  Wa 
country  the  King's  writ  does  not  run,  and  as  the  wilder  Was  are 
inveterate  head-hunters,  requiring,  indeed,  fresh  heads  every  spring 
to  ensure  the  success  of  the  crops  of  the  forthcoming  season,  the 
potentialities  of  wealth  concealed  in  their  valleys  have  hitherto 
failed  to  attract  the  private  prospector. 

In  Lower  Burma  the  gravels  of  the  Sittaung  at  Shwegyin  were 
formerly  washed  by  the  natives.  These  washings,  though  poor,  are 
of  great  antiquity,  and  were  farmed  out  by  the  kings  of  Burma  prior 
to  British  occupation.  In  the  Tenasserim  province  gold  is  reported 
from  the  Ye  river,  and  also  from  the  Henze  Basin,  in  the  latter 
place  occurring  with  the  tin-wash.  The  various  tributaries  of  the 
Tenasserim  river,  besides  carrying  tin,  are  more  or  less  auriferous. 
One  of  these,  the  Khamaungthwe,  about  30  miles  east  of  Tavoy, 
has  been  granted  to  a  syndicate,  by  whom  a  considerable  sum  has 
been  spent  in  prospecting  operations. 

Of  regions  now  inaccessible  to  the  ordinary  prospector,  the 
Hukong  Valley,  at  the  head  of  the  Chindwin  river,  and  Hkamti-Long 
at  the  head  of  the  Irawadi,  are  the  most  noteworthy.  Coarse 
gold  has  been  known  for  many  years  to  exist  in  the  former  valley. 
There  it  is  worked  by  the  Kachins,  mainly  with  slave  labour.  The 
richest  streams  are  reported  to  be  the  Kapdup  and  the  Nam  Kwan. 
The  Hkamti-Long  country,  on  the  other  hand,  promises  deposits 
rather  in  veins  in  the  older  metamorphic  rocks  of  the  Miju  and  the 
Zayul  ranges  than  in  the  alluvial  of  the  rivers.  So  far  as  is  known, 
gold  is  not  sought  for  in  Hkamti-Long. 

a  La  Touche,  Rec.  Geol.  Surv.  India,  XXXV,  1907,  p.  102. 


270  ASIA. 

To  sum  up  the  history  of  gold  exploration  in  Burma  :  Gold- 
quartz  veins  have  been  found,  but  have  proved  small  in  extent 
and  erratic  in  value,  while  of  all  Burma's  numerous  auriferous  allu- 
vial deposits  none  have  been  considered  worthy  of  extended  trial 
except  those  owned  by  the  Burma  Gold  Dredging  Company  above 
Myitkyina.  There  three  dredges  were  at  work  in  1907  with  results 
considered  so  satisfactory  that  a  fourth  dredge  of  greater  capacity 
than  any  of  its  predecessors  was  being  built. 


CHINESE  EMPIRE. 

Chi-li. — Numerous  gold  deposits,  both  vein  and  alluvial,  are 
known  to  exist  in  the  mountainous  portion  of  the  Chi-li 
province  lying  north  and  north-west  of  Pekin.  The  vein 
deposits  appear  to  be  confined  entirely  to  the  Archaean  and  Cam- 
brian (Sinian)  system  of  plutonic  and  metamorphic  rocks,  occurring 
indiscriminately  in  amphibolitic  schists,  quartzites  and  limestones. 
Intrusive  volcanic  rocks  (basalt,  andesite,  and  rhyolite)  occur  in 
scattered  areas/'  So  far  as  they  are  known,  the  gold-quartz  veins 
of  Chi-li  are,  with  few  exceptions,  very  thin  and  small.  Perhaps  the 
most  notable  exception  is  the  gold  vein  of  Chin-chang-kou-liang 
(Long.  119°  56'  E.  ;  Lat.  42°  20'  N.),  40  miles  north-west  of  Chau- 
yang.  It  has  been  worked  for  many  years,  and  has  indeed 
been  driven  on  for  4,000  feet.  The  vein  is  from  4  inches  to  3  feet 
in  width,  and  may  occasionally  widen  to  6J  to  7  feet.  The  oxida- 
tion zone  reaches  a  depth  of  200  feet.  The  values  occur  in  shoots. 
The  ore  is  highly  pyritous,  carrying  10  per  cent,  of  sulphides  (galena, 
chalcopyrite,  pyrite,  and  blende).  Nevertheless,  60  per  cent,  of 
the  gold  is  free-milling.  The  country  is  amphibolite-schist, 
resembling  very  closely  an  altered  diabase.6  The  production  of  the 
mine  in  1901  was  about  200  tons  per  month,  the  ore  averaging  an 
ounce  per  ton.  In  six  years  it  had  yielded  to  native  workmen 
43,000  ounces  gold  from  39,000  tons  ore. 

Near  Chuan-shan-tsze  (Long.  119°  12'  E.  ;  Lat.  42°  26'  N.) 
is  another  of  the  exceptions  to  the  general  rule  of  the  smallness  and 
poverty  of  Chi-li  veins.  The  mine  lies  in  amphibolite-schist  about 
3  miles  (8  li)  east  of  the  village.  The  vein  is  4  inches  to  3  feet 
wide,  and  is  composed  of  pyritous  quartz.  The  ore-shoot  appears 
to  be  about  300  feet  in  length.  According  to  Vogelsang,  it  has  been 
opened  to  a  depth  of  1,100  feet.  The  ore  is  raised  by  a  horse-whim. 
On  the  surface  it  is  heated  to  make  it  brittle,  is  quenched  with  water, 

a  Hoover,  Trans.  Inst.  Min.  Met.,  VIII,  1900,  p.  324. 

"  Vogelsang,    "  Reisen   im    nordlichen    und    mittlern    China,"    Peterm.   Mittheil., 
.LVTI,  1901,  pp.  245  et  seq. 


CHINA.  271 

broken  to  nuts  with  a  hammer,  and  ground  between  stone  rollers. 
Fifteen  such  rollers  are  used,  each  actuated  by  two  mules.  The 
capacity  of  each  mill  is  4001bs.  (300  catties)  in  24  hours.  Concen- 
tration is  effected  on  sloping  tables  and  the  final  separation  is  per- 
formed in  the  batea.  The  average  tenor  of  the  ore  is  one  ounce  per 
ton.  The  annual  production  is  700  ounces.  About  200  workmen 
are  employed.  Six  per  cent,  royalty  is  charged  by  the  Tu-tung 
(prefect)  of  Jehol.  Near  Yu-erh-yai  (Long.  118°  27'  E.  ;  Lat.  40° 
34'  N.)  small  gold-quartz  veins  lie  at  the  contact  of  metamorphic 
limestone,  with  a  granite.  Other  veins  are  known  in  the  Jehol 
prefecture  in  a  gabbroid  rock,  in  diabase,  and  in  granite. 

In  few  places  in  Chi-li  has  gold-quartz  mining  been  profit- 
able to  the  native  owners,  and  despite  the  fact  that  the 
country  has  obviously  been  most  carefully  prospected,  few 
important  auriferous  vein  occurrences  are  known.  The 
placer  deposits  of  Chi-li,  on  the  other  hand,  are  compara- 
tively rich,  and  indeed  furnish  the  greater  proportion  of  the 
gold  obtained  from  the  province.  The  vicinity  of  Ching-chang- 
kou-liang,  mentioned  already  as  possessing  a  rich  quartz  vein,  was 
especially  productive,  as  is  evidenced  by  the  fact  that  the  Chinese 
have  driven  a  tunnel  3,000  feet  in  length,  to  drain  a  buried  alluvial 
basin.  General  depression  of  the  country  has  hidden  much  of  the 
ancient  river-channel  system  beneath  great  thicknesses  of  alluvium 
and  of  loess.  The  total  gold  production  of  Chi-li  in  1898  was  esti- 
mated at  50,000  ounces. 

Shantung. — The  geology  of  the  Shantung  province,  so  far  as  it 
concerns  metalliferous  deposits,  is  identical  with  that  of  Chi-li. 
Gold-quartz  veins  are,  however,  not  so  widely  distributed,  nor  is  the 
yield  of  gold  so  large,  being  for  1898  only  6,000  ounces.  The 
principal  gold  mine  appears  to  be  the  Chow-yen  (Mountain  of  Gold), 
40  miles  from  Chefoo,  discovered  and  worked  as  long  ago  as  1620  a.d. 
Its  vein  is  of  great  width,  ranging  from  30  to  90  feet  for  a  length  of  a 
mile.  The  ore  occurs  in  indefinite  shoots,  and  carries  from  15  to 
20  per  cent,  pyrites,  the  latter  often  occurring  in  great  masses.  The 
ore  is  distinctly  low-grade.  Forty  per  cent,  of  the  gold  is  free."  The 
mine  is  estimated  to  contain  about  200,000  tons  available  ore, 
worth  about  £2  per  ton.  It  is  owned  by  Chinese.6  Gold  mines 
were  opened  at  P'ing-tu,  also  in  the  Shantung  province,  in  1884. 
The  ore  is  highly  pyritous,  and  the  lode  has  been  worked  down  to 
the  sulphide-level.  The  concentrates  from  the  primitive  stamp  mills 
are  sold,  after  treatment  and  re-treatment,  to  native  farmers,  who 
carry  them  home  and  occupy  their  leisure  time  in  the  winter  months 


a  Hoover,  loc.  cit.  sup. 

6  Curie,  "  Gold  Mines  of  the  World,"  London,  1905,  p.  216. 


272 


ASIA. 


in  fine-grinding  and  re-panning  the  pyrites.  Other  auriferous 
occurrences  are  known  and  have  been  mentioned  by  various  writers, 
but  none  appear  to  be  of  sufficient  extent  or  value  to  warrant 
detailed  description. 

Weihaiwci. — Mining  operations,  both  on  placers  and  on  veins, 
have  been  carried  on  in  the  vicinity  of  Weihaiwei  for  many  years 
by  the  Chinese.  Vein-mining  was,  however,  confined  to  the  outcrops 
and  oxidised  zones  of  the  reefs,  where  the  gold  was  free  and  easily 
saved.  In  1902  the  Weihaiwei  Gold  Company  was  formed  to  work 
a  vein,  the  outcrop  of  which  had  already  been  attacked  by  the 
Chinese.  The  mine  lay  among  low  hills  at  an  altitude  of  5,000  feet 
above  sea-level,  and  at  a  distance  of  10  miles  from  the  port  of  Wei- 
haiwei. The  country  of  the  vein  is  gneiss,  traversed  both  by  acidic 
and  by  basic  dykes,  the  acidic  (aplite  and  pegmatite)  being  crossed 
by  the  basic  intrusives.  The  ore-body  was  some  20  feet  in  width, 
and  gave  an  average  assay  value  of  37s.  6d.  over  the  whole  width." 
Free  gold,  to  the  extent  of  25  per  cent,  of  the  total  yield,  was  accom- 
panied by  auriferous  pyrite,  galena,  and  chalcopyrite.  The  quartz 
of  the  vein  appeared  to  largely  replace  an  original  dyke.  The 
company  erected  a  20-stamp  mill,  and  for  some  time  treated  2,500  tons 


Fig.  96.     Oke-shoots  ih  Aplitic  Dyke,  Weihaiwei  (Versclioyle). 
1.  Gneiss  with  pegmatite  veins.     2.  Aplitic  dykes.     3.  Diorite  dykes. 

of  5|  dwt.  ore  per  month,  but  considerable  difficulty  was  experienced 
in  treating  the  sulphide  ores,  which  were  eventually  shipped  to 
smelters  in  America  for  treatment.  Operations  were  never  very 
profitable  and  eventually  ceased  in  1907. 

Szechuen. — Little  is  known  of    the  auriferous  occurrences   of 
Szechuen  province.     The  beaches  of  the  Upper  Yang-tse  in  several 

a  Versclioyle,  Eng.  Min.  Jour.,  Nov.  17,  1906,  p.  919. 


CHINA.  273 

places  afford  a  scanty  livelihood  to  gold-washers,  who  work  over  the 
gravels  renewed  from  year  to  year  by  the  floods  of  the  wet  season. 
The  only  gold  mine  of  any  size  known  to  Europeans  is  at  Maha 
(Long.  102°  05'  E. ;  Lat.  28°  15'  N.)  Although  alluvial  gold  has  been 
recovered  from  this  neighbourhood  for  many  years,  the  gold-quartz 
veins  of  Maha  have  been  worked  only  since  1880.  At  one  time  no 
less  than  15,000  men  were  employed.  The  ore  is  crushed  partly 
by  Huntington  mills  and  partly  by  80  primitive  Chinese  stamps 
actuated  by  40  overshot  wheels.  The  mine  is  situated  at  an  altitude 
of  10,000  feet."  Alluvial  gold  in  small  quantity  is  reported  also 
from  Kai-ja,  25  miles  south-west  of  Maha  ;  from  Yen-Ching  (Long. 
101°  45'  E.  ;  Lat,  27°  25'  N.)  ;  and  from  the  sands  of  the  Fu  above 
Kiating. 

Deserted  gold  mines  are  known  near  Feng-ko  on  the  Upper 
Yangtse  (Long.  100°  30'  E.  ;  Lat.  27°  45'  N.)  ;  theMuli  (Tibetan) 
country  further  north  on  the  Lithang  river  produces  considerable 
quantities  of  gold-dust. b 

Yunnan. — In  Yunnan  numerous  small  gold  mines  occur  along 
the  north-  and  south-running  geomorphic  folds  developed  by  great 
Miocene  movements.0  The  gold-quartz  veins  have  been  exposed 
only  by  native  labour,  and  no  foreign  work  has  as  yet  been 
permitted.  The  only  mine  actually  producing  gold  in  1907  was 
that  of  Ta-lan  (Talangting),  famous  throughout  Yunnan.  Its 
glories  have  been  depicted  in  glowing  terms  to  the  present  writer 
even  in  a  region  as  far  distant  from  Ta-lan  as  the  Shan  States. 
Ta-lan  is  situated  exactly  on  the  Tropic  of  Cancer  in  east 
long.  101°  45'.  The  mines  lie  nine  miles  from  the  town  in  the 
hills  to  the  north-east,  and  are  at  an  elevation  of  some  7,300  feet 
above  sea-level.  Here  intrusive  volcanic  rocks  have  broken  through 
the  Palseozoic  shales,  slates,  sandstones,  and  limestones  of  the 
Yunnan  plateau.  Throughout  the  intrusive  rock  are  fine  veins  of 
quartz.  The  auriferous  area  is  said  to  cover  about  a  square  mile. 
Some  3,000  men  are  employed,  and  work  in  the  crudest  fashion.  The 
output  is  nominally  about  3,000  ounces  per  annum,  but  is  probably 
much  more.  The  mines  have  been  worked  for  some  60  years,  the 
Chinese  Government  receiving  a  royalty  of  18  per  cent.  The  ore  is 
broken  up  with  hammers  and  then  pounded  fine  in  an  ordinary 
self-acting  paddy  (rice)  mortar.  It  is  then  washed  over  grooved 
tables.  The  loss  is  evidently  great,  as  many  men  make  a  liveli- 
hood by  collecting  and  re-washing  the  tailings.  The  gold  is 
apparently  unevenly  distributed  in  the  veins,  and  rich  pockets  are 

a  Jack,  "  The  Back  Blocks  of  China,"  London,  1904,  p.  101. 

b  Johnston,  "  From  Peking  to  Mandalay,"  London,  1908,  p.  238. 

c  Leclere,  Ann.  des  Mines,  Ser.  9,  XX,  1901,  p.  445. 

S 


274  asia. 

occasionally  met  with.  A  yield  of  an  ounce  to  the  ton  (5  fen  to 
100  catties)  is  considered  to  be  the  lowest  payable  return.  The 
oxidised  zones  yield  occasionally  as  much  as  20  ounces  per  ton. 
Owing  to  the  crude  methods  of  working  the  total  output  of  quartz 
per  miner  is  probably  a  little  more  than  two  tons  per  annum. 
It  is  probable  that  the  Ta-lan  intrusive  rock  is  an  andesite  of 
the  same  character  as  that  which  occurs  sporadically  in  Burma. 

At  Kin-kiang,  about  60  miles  from  Tali-fu,  and  at  the  spot  at 
which  the  Blue  river  takes  the  name  of  Kin-cha-kiang,  are  rich  con- 
glomerate beds,  perhaps  100  yards  in  thickness.  Their  tenor  is 
unknown,  but  500  gold-washers  are  engaged  in  working  on  them. 
The  washers  use  wooden  trays  much  like  those  in  vogue  in  India 
and  Burma.  Their  earnings  are  certainly  small,  perhaps  no  more 
than  3d.  to  6d.  (1|  to  3  grains  gold)  per  day.  These  workings 
have  been  known  since  at  least  the  24th  year  of  Kang-hi  (1685  a.d.). 

Jack®  heard  of  gold  mines,  both  in  quartz  and  alluvial,  two 
stages  from  Manwyne,  on  the  Shweli  (Loonkiang)  river  ;  and  also 
of  gold-quartz  veins  in  the  mountains  between  the  Mekhong  and 
the  Salween  at  about  27°  20'  north  latitude. 

Gamier b  heard  of  four  gold  mines  in  Yunnan,  viz.,  that  at 
Kin-cha-kiang,  above-mentioned  ;  at  Ma-ku  (opened  in  1730  a.d.), 
on  the  borders  of  Yunnan,  and  near  Linngan ;  Ma-kang 
(opened  1744  a.d.),  south  of  Tchong-tien,  and  west  of  the 
famous  silver  mines  of  Ngan-nan ;  and  Houang-tsao-pa  to 
the  west  of  Teng-yueh.  The  last  is  possibly  that  mentioned  by 
Jack  as  lying  two  marches  from  Manwyne,  though  the  positions 
given  do  not  exactly  coincide. 

Fo-Kien. — A  valuable  goldfield  is  said  to  exist  in  the  Shao-wu 
(Cha-oo)  district  of  Fo-Kien  province.  Shao-wu  lies  about  150  miles 
north-west  of  Foo-chow,  and  is  on  the  eastern  flanks  of  the  Yung- 
ling  mountains. 

The  total  gold  output  of  China  cannot  of  course  be  estimated 
with  an  approach  to  accuracy,  but  may  be  considered  to  range 
between  £300,000  and  £400,000  per  annum. 


MANCHURIA. 

Liau-tung  Peninsula. — The  auriferous  deposits  of  the  Liau- 
tung  Peninsula  are  divided  by  Bogdanovitch c  into  four  classes  : 
(a)  Those  in  existing  stream  beds  :  These  are  of  little  importance. 
The  Chinese  wash  the  annually  formed  surface  deposits  from  year  to 

a  Loc.  cit.  sup. 

b  Voyage  d'Exploration  en  Indo-Chinie,  1867,  I,  p.  230. 

c  Materialen  zur  GeologieTlusslands,  XX,  1900,  p.  240. 


MANCHURIA.  275 

year,  and  always,  of  course,  at  the  same  spots  in  the  stream  beds. 
(6)  Pleistocene  high-level  gravels  :  These  are  worked  east  of  Laio- 
tie-chan,  near  the  village  of  Chandze-toun  (121°  12'  E.  ;  38°  43'  N.) 
to  the  south-west  of  Port  Arthur.  The  pay-gravel  is  extracted 
by  sinking  closely  adjacent  pits  through  the  overburden  and  en- 
larging these  at  the  bottom  when  the  pay-streak  is  reached.  The 
overburden  is  only  from  5  \  to  1\  feet  thick,  while  the  pay-streak  is  from 
6  to  8  inches  deep.  The  tenor  of  the  latter  is  from  9  to  14  grains  per 
metric  ton.  (c)  Ancient  valley  alluvials  :  Four  pits  sunk  on  the 
eastern  slope  of  Laio-tie-chan  proved  the  presence  of  an  auriferous 
gravel  bed.  Its  thickness  varied  from  2  to  4  feet,  while  that  of  the 
barren  overburden  was  from  9  to  27  feet.  The  Chinese  dug  to 
bed-rock,  finding  fairly  coarse  grains  of  gold  on  the  bottom.  The 
tenor  of  the  pay-streak  was  from  7  to  14  grains  per  metric  ton. 
(d)  Auriferous  marine  placers  formed  by  the  concentrating  action  of 
the  sea  waves  and  currents  on  the  gravels  brought  down  by  the 
streams  from  the  above-mentioned  deposits  :  the  Chinese  work 
these  placers  during  ebb-tide,  the  greatest  width  of  beach  exposed 
being  some  60  yards.  The  thickness  of  the  black-sand  beds  thus 
rendered  accessible  is  about  a  foot.  They  lie  on  the  upturned 
edges  of  argillaceous  strata.  The  Chinese  gather  the  sand  as  far 
seaward  as  possible,  since  the  further  out,  the  fewer  pebbles  there 
are.  Fifteen  Chinamen  can  recover  2|  tons  of  sand  mixed  with 
pebbles  in  one  ebb-tide.  On  washing,  this  quantity  yields  2-6 
ounces  (81  grammes)  gold  in  grains  and  slugs  of  a  fineness  of  869. 
During  two  ebb-tides  at  the  end  of  November,  and  under  the 
above  conditions,  Bogdanovitch  collected  5-3  ounces  (166 grammes), 
in  which  was  a  slug  of  1-77  ounces  (55-4  grammes).  The  old  gravels 
near  Pei-lien-tsa  were  discovered  about  1874  and  the  marine 
placers  much  later.  Very  low-grade  thin  gold-quartz  veins  traverse 
the  quartzose  and  argillaceous  schists  of  the  neighbourhood,  and 
the  degradation  of  these  has  probably  furnished  the  gold  of  the 
auriferous  sands  and  gravels. 

Both  recent  and  high-level  gravels  occur  in  the  neighbourhood 
of  Port  Arthur,  and  also  to  the  east  at  Siao-pin-tao  (Long.  121°  30' 
E.  ;  Lat.  38°  49' N.).  Here  also  there  is  a  marine  placer,  at  the  base 
of  which  pebbles  containing  gold  are  occasionally  found.  Else- 
where in  the  Liau-tung  peninsula  gold  is  found  to  the  east  of  Port 
Adams  near  the  lake  Gou-tsia-pao-tsi  (Long.  122°  02'  E.  ;  Lat.  39° 
24'  N.),  where  the  Chinese  have  exploited  deep  placers.  Auriferous 
veins  occur  in  the  neighbourhood  of  the  lake  in  the  Taku-chan  series 
of  rocks.  Similar  auriferous  alluvial  deposits  occur  near  the  temple 
of  Youhon-din-miao,  and  near  the  village  of  Chou-tsia-toun-pei-gu, 
about  15  J  miles  south-west  of  Pi-tsze-wo.  These  lie  on  amphi- 
bolitic  schists  and  gneisses,  that  are  intruded  by  pyritous  granite- 


276  asia. 

porphyry  closely  resembling  the  beresite  (microgranite)  of  the 
Urals.  Assays  of  adjacent  veins  gave  from  1  to  5  dwts.  gold  per 
metric  ton.  The  pyrites  was  also  auriferous,  averaging  in  tenor 
about  1  dwt.  gold,  though  exceptional  assays  showed  results  as  high 
as  32  ounces  per  metric  ton.a 

In  Northern  Manchuria  several  rich  gold  deposits  are  believed 
bo  exist.  Von  Cholnoki^  reports  an  auriferous  bed  in  the  basin  of 
the  San-tao,  originating  apparently  from  the  degradation  of  gold- 
quartz  veins  in  granite  and  gneiss.  At  Tsi-tz'-Kouho,  near  Kirin, 
such  veins  have  been  worked.  The  basin  of  the  Au-hao  carries 
gold,  as  also  do  the  gravels  of  the  Great  Chingan,  though  in  both 
cases  in  small  quantities.  The  gold  mines  of  the  province  of  Cheilun- 
tzian  (Heilungchiang),  which  since  the  Boxer  troubles  had  been 
seized  by  the  Russians,  were  restored  to  the  Chinese  in  1907.  Three 
mines  are  known  :  Quan-in-chan,  Mo-che,  and  Quan-che.  These 
were,  after  their  resumption  by  the  Chinese,  worked  directly  by 
Chinese  officials,  but,  the  venture  proving  unsuccessful,  they  were 
handed  back  to  the  native  Manchurian  miners,  the  Chinese  Govern- 
ment taking  a  substantial  royalty.0 


KOREA. 

The  median  chain  of  the  Korean  peninsula  is  composed  of 
ancient  crystalline  schists  and  granites  through  which  recent  vol- 
canic rocks  have  been  intruded.  The  general  altitude  of  its  higher 
peaks,  situated  in  the  north  of  Korea,  where  are  also  the  gold-mining 
districts,  is  from  5,000  to  6,000  feet.  The  placer  deposits  of  Korea 
have  long  been  worked  by  the  natives  and  are,  or  were,  until  the 
establishment  of  the  Japanese  protectorate,  the  property  of  the  Im- 
perial household.  In  1898  concessions  to  foreigners  were  granted, 
one  to  each  foreign  nation  then  interested  in  Korean  affairs.  They 
were  given  for  a  term  of  25  years  on  condition  of  a  payment  to  the 
Emperor  of  a  royalty  of  25  per  cent,  of  the  net  profits.  Four  such 
concessions  were  taken  up  :  one  each  by  Americans,  British,  Ger- 
mans, and  Japanese.  The  last  proved  worthless.  The  German 
concession  lay  at  Tank-kogae,  some  100  miles  north-east  of 
Seoul,  and  in  the  centre  of  a  flourishing  placer  industry 
that  had  been  in  existence  for  50  years,  and  where  at  one 
time  20,000   men  had  been  employed.     An   extension   of  a  year 

a  Pervinquiere,  Rev.  Scientif.,  Ser.  5,  I,  1904,  p.  547. 
6  Foldtani  Kozloni,  XXIX,  1900,  p.  289. 
c  Min.  Jour.,  Nov.  2,  1907. 


KOREA.  277 

was  given  to  the  native  miners  to  work  out  their  holdings,  and 
when  the  Germans  finally  took  possession,  much  of  the  richer 
pay-dirt  had  been  exhausted.  The  maximum  thickness  of 
the  overburden  above  the  pay-streak  is  estimated  at  75  feet. 
The  alluvial  gold  is  fairly  coarse,  and  nuggets  of  half-an-ounce  in 
weight  are  not  rare.  The  fineness  is  about  920/f  Extended 
prospecting,  both  in  the  alluvial  gravels  and  on  the  adjacent 
quartz  veins  from  which  the  alluvial  gold  had  been  derived  failed 
to  yield  any  deposit  of  economic  value,  and  the  concession  was 
abandoned. 

The  British  concession  was  located  at  Yuen-san,  where  a  rich 
ore-shoot  was  worked  for  some  time.  On  its  exhaustion,  and  on 
the  failure  of  the  subsequent  endeavours  to  find  new  ore-bodies, 
this  concession  also  retroceded  to  the  Korean  Crown. 

The  American  grant,  on  the  other  hand,  has  been  profitable 
from  the  commencement  of  mining  operations.  It  lies  at  Unsan 
in  the  extreme  north-west  of  Korea,  near  the  Manchurian  frontier. 
(Long.  126°  10'  E. ;  Lat.  40°  02'  N.).  It  has  an  area  of  400  to  500 
square  miles,  containing  three  distinct  groups  of  mines  separated 
by  distances  of  some  20  miles.  The  groups  are  Chittabalbie  and 
Maibong  ;  Kuk  San  Dong  ;  and  Tabowie  and  Taracol,  forming 
together  the  Oriental  Consolidated  Mines.  Gold  occurs  here  in 
banded  quartz  veins  in  granite.  The  veins  contain  a  good  deal  of 
country,  which  is,  as  a  rule,  highly  graphitic.  The  total  quantity 
of  sulphides  present  in  the  ore  amounts  to  10  per  cent.  The  sul- 
phides are  pyrite,  galena,  and  blende  ;  of  these  the  two  last  are 
considered  certain  indications  of  rich  ore.  The  gold  is  fine  and  is 
seldom  visible  in  the  quartz.1^  There  are  five  separate  stamp-mills 
in  operation,  one  at  each  of  the  above-mentioned  mines,  and  in  all 
220  stamps  are  at  work.  To  July,  1906,  about  a  million  tons  of 
ore  had  been  crushed,  for  an  average  recovery  of  33s.  4d.  per  ton. 
Another  million  tons,  worth  about  £1  per  ton,  was  available.  The 
total  costs  per  ton  in  1906  were  9s.  3d.  The  original  royalty  of 
25  per  cent,  of  the  profits  has  been  modified  to  an  annual  payment 
of  £2,500.     The  annual  produce  of  these  mines  is  about  £250,000. c 

In  addition  to  the  foregoing,  numerous  placers  are  known 
at  Chungkeung  (near  Kaichchou),  Kalmoru  (43  miles  north  of 
Changjim),  at  Kangwondo,  &c,  and  in  Hpyengan-To  generally. 
These  are  still  being  worked  in  native  fashion,  and  yield  large 
quantities  of  alluvial  gold.      In   1894    the    production  of  gold  in 

a  Hamilton,  Min.  Jour.,  June    28,    1902 ;    Bauer,    Zeit.  f  iir    prakt.    Geol.,    XIII, 
1905,  p.  69. 

b  Speak,  Trans.  Inst.  Min.  Met.,  XII,  1903,  pp.  237,  427. 

c  Curie,  Eng.  Min.  Jour.,  Aug,  18,  1906,  p.  296. 


278 


ASIA. 


Korea    was  £195,844  (4,896,120    francs)  ;    by    1900    it    had    risen 
to  £844,879  (21,121,989  francs)/1 
Recent  returns  are  : — 


Kg. 

Ounces. 

Value,  Sterling. 

1905 
1906 

3,892 
3,488 

124,933 
111,965 

£531,528 
476,334 

JAPAN. 

The  long  isolation  of  Japan  from  the  Western  World  since  the 
early  years  of  the  seventeenth  century  is  doubtless  responsible 
for  the  general  neglect  to  recognise  that  Empire  as  one  of  the 
chief  contributors  to  the  flood  of  gold  that  poured  into  Europe 
during  the  sixteenth  century.  European  trade  with  Japan  opened 
with  the  appearance  on  its  shores  in  1542  of  Mendez  Pinto,  the  Portu- 
guese adventurer,  to  use  no  stronger  term.  By  1600,  the  export  of 
gold  had  assumed  enormous  proportions,  and  thousands  of  natives 
were  engaged  in  exhausting  the  more  accessible  auriferous  deposits. 
In  1611  the  first  signs  of  revolt  against  Portuguese  domination  were 
evinced,  and  by  1624  the  last  Portuguese  had  been  expelled  after 
an  arduous  struggle.  A  few  Dutch  were  permitted  to  remain  and 
to  trade,  but  under  the  most  humiliating  conditions.  The 
following  is  the  estimated  amount  of  gold  exported  from  the 
country  by  the  Portuguese  and  the  Dutch  respectively  during  the 
period  of  intercourse  : — h 

Portuguese 1545-1598     £6,000,000 

1599-1625      54,000,000 


Dutch  (Gold  alone) 


1611-1646 
1647-1706 
1707-1840 


£60,000,000e 

£9,400,000 
4,600,000 
1,000,000 


£15,000,000 

Since  the  present  yield  of  Japan  is  only  some  £350,000  per 
annum,  it  is  probable  that  the  above  sums  represent  the  exhaus- 
tion of  the  placers  and  the  enriched  vein  outcrops. 

Yezo  (Hokkaido). — The  island  of  Yezo  carries  the  most  impor- 
tant placer  deposits  in  Japan.  The  source  of  the  gold  is  quartz 
veins  in  the  Palaeozoic  formations.  The  most  celebrated  locality 
is    Esashi   (Lat.  44°  55'  N.  ;    Long.  142°  30'  E.),    the  Klondike  of 

"  Pervinquiere,  Revue  Scientifique,  Paris,  5,  I,  1904,  p.  545. 
h  Del.  Mar,  "  History  of  the  Precious  Metals,"  London,  1880,  p.  134. 
•    c  Gold  and  silver,  of  which  probably  £20,000,000  was  gold. 


JAPAN. 


279 


Japan.  At  Esashi  in  1899  there  were  collected  14,358  ounces 
(119,082  momme)  including  one  nugget  of  23  •  9  ounces  (198  momme) 
in  weight.  During  1902  the  principal  alluvial  mines  in  Hokkaido 
yielded  : — a 

Ounces. 


Shintotsugawa 

Usotannai... 

Peichan 


6,616 
4,074 
2,196 


Numerous  alluvial  gold  occurrences  are  found  in  the  provinces 
of  Kitami,  Teshio,  Teshiro,  Ishikari,  Hidaka,  Iburi,  Shiribeshi,  and 
Oshima.&  In  Ishikari  and  Hidaka  platinum  and  osmiridium  occur 
with  the  gold.  The  following  table  shows  the  value  of  the  placer- 
gold  output  of  Yezo  during  recent  years  : — c 


Sterling. 

Sterling. 

1898 

£5,100 

1903 

£48,863 

1899 

48,643 

1904 

14,173 

1900 

111,143 

1905 

11,805 

1901 

101,080 

1906 

8,142 

1902 

63,367 

The  only  gold-quartz  mine  of  importance  in  Yezo  is  the  Pon- 
shikaribets  mine,  lying  about  7£  miles  (3  ri)  south  of  the  Yoichi, 
Shiribeshi  Province.  The  country  is  a  Tertiary  volcanic  tuff  often 
intersected  by  andesite  dykes.  The  veinstone  is  rhodochrosite  and 
quartz,  and  the  accompanying  sulphides  are  auriferous  argentite, 
galena,  chalcopyrite,  and  zinc  blende.  The  reefs  vary  in  width 
from  5  inches  to  30  feet.  The  gold  yield  from  this  mine  for  the  three 
years  1898-1900  was  115,580  ounces  (957,009  momme). 

Honshu  (Hondo). — Honshu,  next  to  the  south,  is  the  largest 
island  of  the  Japanese  group.  It  contains  several  placer  deposits 
of  no  great  importance.  Their  gold  content  is  derived  mainly  from 
the  degradation  of  quartz  veins  in  Tertiary  andesitic  tuffs  and 
lavas. 

In  the  Ugo  province  in  the  north  of  Honshu  the  chief  gold- 
quartz  veins  are  at  the  Matsuoka  and  the  Okuzu  mines.  In  the 
former  the  auriferous  deposit  is  a  stockwork  at  the  contact  of 
liparite,  with  Tertiary  strata.  The  sulphides  are  argentiferous 
galena,  zinc  blende,  and  pyrite.  Its  produce  is  small,  being  for  the 
three  years  1898-1900  only  95-6  ounces  (794  momme). 


«  Weigall,  Trans.  Inst.  Min.  Met.,  XV,  1906,  p.  206. 
b  "  Geology  of  Japan,"  Tokyo,  1902,  p.  130. 
c  Gordon,  Cons.  Rep.,  1907. 


280  ASIA. 

The  Okuzu  mine  is  8|  miles  south-west  of  the  town  of  Hanawa. 
Its  veins  were  discovered  in  1604.  The  country  is  Tertiary  tuff 
and  augite-andesite.  The  width  of  the  veins  varies  from  a  few 
inches  to  2  or  3  feet.  Chalcopyrite  and  pyrite  and,  rarely,  sphalerite 
are  the  associated  sulphides.  The  yield  of  this  mine  from  1896 
to  1900  was  1,227  ounces  (10,157  momme). 

In  the  Ugo  province  the  Innai  mine,  one  of  the  most  famous 
silver  mines  of  Japan,  produces  some  3,000  ounces  of  gold  annually, 
in  addition  to  400,000  ounces  silver. 

In  the  Iwashiro  province  some  distance  north  of  Tokyo  and 
towards  the  eastern  coast,  are  several  gold  mines.  The  Handa 
mine,  about  a  mile  west  of  Kori  railway  station,  is  believed  to  have 
been  worked  for  at  least  1,000  years.  Its  veins  run  through 
Tertiary  strata  and  liparite,  and  vary  in  thickness  from  3  to  10 
feet.  The  veinstone  is  principally  quartz  associated  with  calcite, 
the  former  being  sometimes  amethystine  in  character.  The  accom- 
panying sulphides  are  auriferous  argentite,  together  with  sphalerite 
and  minor  quantities  of  galena,  chalcopyrite,  pyrite.  Native  silver 
is  occasionally  found.  The  gold  yield  from  1896  to  1900  was  2,351 
ounces  (19,469  momme).  The  Takadama  mine,  2 h  miles  from 
Atami  station,  is  supposed  to  have  been  first  worked  in  the 
ninth  century  a.d.  Its  yield  is  very  small,  and  in  its  geological 
character  it  is  similar  to  the  Handa  mine. 

The  Hashidate  mine  is  situated  in  Echigo  province,  lh  miles 
south-west  of  Itoigawa,  on  the  west  coast.  Its  values  are  believed 
to  lie  in  quartz  veins  in  Palaeozoic  rocks. a  The  gold  yield  for 
1896  to  1900  was  8,043  ounces  (66,601  momme). 

The  Kaga  province,  immediately  to  the  south,  furnishes  two 
gold  mines,  the  Kanahira  and  the  Kuratani,  the  latter  being  14 
miles  south  of  Kanazawa.  The  country  in  each  case  is  liparite 
and  Tertiary  tuffs,  traversed  by  numerous  small  veins.  The  vein- 
stone of  the  former  mine  is  barytes  and  quartz  ;  of  the  latter, 
rhodochrosite,  barytes,  and  calcite.  Associated  with  the  gold 
are  galena,  sphalerite,  and  pyrite.  The  yield  of  the  Kanahira  veins 
from  1896  to  1900  was  3,443  ounces  (28,515  momme),  and  of  the 
Kuratani  for  the  same  period  was  8,314  ounces  (68,843  momme). 

In  the  Kai  province,  west  of  Tokyo,  is  the  Ho  mine,  which  has 
been  worked  since  1681  a.d.  The  quartz  veins  of  this  mine  contain 
native  gold  in  Palaeozoic  clay-slate  and  sandstone. 

The  most  important  mines  of  Honshu  are  probably  those  in 
the  Tajima  province,  north-west  of  Kioto.      The  Kosen  mine  lies 

a  Loc.  cit.  sup.,  p.  124. 


JAPAX.  281 

near  the  coast,  10  miles  north-west  of  Toyooka,  the  principal  town 
of  Tajima  province.  Its  rock  is  granite,  traversed  by  propylite 
dykes.  Two  principal  mineral  veins  are  found  in  the  granite,  but 
the  occurrence  is  evidently  closely  related  to  the  younger  intrusive 
rocks.  The  gold  occurs  with  quartz,  argentite,  pyrite,  and  galena. 
The  Ikuno  mines,  further  south  and  near  the  town  of  Ikuno,  are 
perhaps  the  most  famous  in  Japan.  They  are  said  to  have  been 
discovered  in  807  a.d.  The  three  principal  mines  are  the  Tasei, 
Kanagase,  and  Kasei.  At  the  Tasei  the  country  is  liparite,  pro- 
pylite, and  Tertiary  volcanic  tuffs.  Similar  rocks  occur  at  Kanagase 
but  there  they  are  traversed  by  basaltic  dykes.  At  the  Kasei 
the  country  is  diorite,  intersected  by  liparite  and  propylite  dykes. 
The  gangue  of  the  lodes  generally  is  quartz,  calcite,  and  rhodo- 
chrosite,  and  the  gold  occurs  with  argentite,  pyrite,  chalcopyrite, 
bornite,  fahlore,  galena,  stibnite,  pyrargyrite,  and  sphalerite.  The 
veins,  as  a  rule,  are  very  large  and  of  great  length.  The  Kasei 
lode,  for  example,  is  5,300  feet  long  and  nearly  50  feet  wide.  The 
yield  of  these  mines  from  1896  to  1900  inclusive  was  16,449  ounces 
(136,202  momme). 

The  only  other  gold  mine  requiring  notice  in  the  main  island 
is  the  Omori,  in  the  Iwami  province,  due  north  of  Hiroshima. 
This  mine  was  opened  about  600  years  ago.  Its  rocks  are  hyper- 
sthene-quartz-andesite  lavas  and  agglomerates,  with  which  are 
associated  Tertiary  sedimentary  strata.  Its  deposits  fall  into  two 
groups  :  The  Eikyu,  in  the  solid  hypersthene-quartz-andesite,  and 
the  Hontani  stockworks  and  impregnations  in  the  agglomerate.  In 
the  former  group  the  veins  are  1  to  2  feet  thick,  and  consist  of  quartz 
and  pyrite.  The  gold  is  associated  generally  with  chalcopyrite.  In 
the  Hontani  type  the  ores  are  native  silver,  argentite,  siderite,  and 
malachite.  The  yield  of  recent  years  from  this  mine  has  been 
small. 

Sado. — The  Aikawa  mine,  famous  in  Japanese  annals,  is  near 
Aikawa,  on  Sado  island,  which  lies  off  the  north-east  coast  of 
Honshu.  The  veins  were  discovered  in  1600  a.d.,  and  yielded 
enormously  for  many  years.  They  traverse  augite-andesite  tuffs 
and  Tertiary  shales.  Three  principal  veins  are  mined,  occasionally 
for  great  widths,  the  Aoban,  the  southernmost,  attaining  a  working 
width  of  100  feet.  The  Torigoe  vein,  the  northernmost,  varies 
from  5  to  50  feet,  and  the  Otate  from  2  to  10  feet  in  width. 
The  two  outer  veins  have  a  length  of  at  least  4,000  feet.  The 
veinstone  is  mainly  quartz  and  calcite,  at  times  carrying  pearl- 
spar  and  gypsum.  Native  gold  and  silver  occurs  with  argentite, 
chalcopyrite,  pyrite,  blende,  and  galena,  together  with  occasional 


282  ASIA. 

specimens  of  stephanite,  pyrargyrite,  marcasite,  and  arsenopyrite. 
The  gold  yield  from  1896  to  1900  was  33,851  ounces  (280,292 
momme). 

Kyushu  (Kiushiu). — The  Kyushu  island  is  the  most  southerly 
of  the  large  islands  of  the  Japanese  group.  Its  principal  mines  are  in 
the  Chikugo  and  Satsuma  provinces.  The  Hoshino  mines,  12  miles 
east  of  Fukushinia,  in  the  first-named  province,  are  in  augite- 
andesite,  intrusive  through  Palaeozoic  rocks.  The  veins  are  10  to 
20  feet  wide,  and  are  impregnated  with  pyrite,  and  more  rarely 
with  sphalerite.  The  most  productive  are  the  Komuro  and  the 
Yamo.  In  the  Satsuma  province,  in  the  south-west  corner  of  the 
island,  are  the  Serigano,  Yamagano,  and  Kago  mines.  The  first 
is  24  miles  north  of  Kagoshima.  It  was  discovered  in  1652,  and  has 
since  been  worked  almost  continuously.  The  country  is  augite- 
andesite,and  the  veins  varv  in  thickness  from  a  few  inches  to  9  feet. 
Pyrite  and  chalcopyrite  are  usually  associated  with  the  vein-quartz. 
The  yield  of  the  Serigano  mine  from  1896  to  1900  was  2,052  ounces 
(16,991  momme). 

The  Yamagano  mine  lies  17  miles  north  of  Kajiki,  the  principal 
town  of  Osumi  province.  It  was  discovered  about  the  same  time 
as  the  Serigano  mines,  and  is  said  in  one  year  (1659)  to  have  yielded 
about  60,000  ounces  of  gold.  The  rocks  of  the  neighbourhood  are 
Tertiary  shales  and  sandstones  intruded  by  augite-andesite.  The 
andesite  is  traversed  by  numerous  auriferous  veins,  the  thinner 
veins  forming  stockworks  particularly  rich  at  the  intersections. 
The  larger  veins  are  often  20  to  30  feet  in  thickness.  The  veinstone 
is  quartz  with  calcite  and  pyrite.  Native  gold  occurs  with  argentite, 
or,  more  rarely,  with  chalcopyrite.  From  1896  to  1900  these  mines 
produced  11,932  ounces  gold  (98,801  momme). 

The  Kago  mines  are  in  the  extreme  south  of  the  Satsuma 
province,  and  3H  miles  south  of  Kagoshima.  They  were  discovered  in 
1683.  The  country  is  Mesozoic  clay-slate  and  sandstone  intruded 
by  Tertiary  quartz-porphyry  and  andesite  dykes,  which  do  not,  as 
a  rule,  appear  at  the  surface.  The  gangue  is  quartz  and  clay.  The 
production  of  these  mines  is  small,  not  amounting  to  more  than 
700  ounces  per  annum. 

From  the  foregoing  it  will  be  seen  that  the  majority  of  the 
gold-quartz  veins  of  Japan  have  been  worked  for  many  generations. 
In  these  cases  the  gold  of  the  zones  of  oxidation  and  secondary 
enrichment  may  be  expected  to  have  been  exhausted,  leaving  only 
the  poorer  sulphide  zones.  In  nearly  every  case  it  may  be  noted  that 
the  gold-quartz  veins  are  associated  with  Tertiary  andesitic 
intrusions. 


JAPAN. 


283 


During  recent  years  the  gold  yield  of  Japan,  exclusive  of  that 
of  Formosa  (given  in  another  place),  has  been  as  follows  : — 


Crude  Ounces. 

Crude  Ounces. 

1881-1890 

1891-1900 

1901 

1902 

1903 

146,062 

345,287 

75,591 

95,670 

100,774 

1904 
1905 
1906 
1907 

88,719 
95,173 
95,747 

88,653 

FORMOSA  (Taiwan). 

Formosa,  in  common  with  other  Eastern  countries,  has  been 
represented  by  early  European  travellers  as  a  repository  of  untold 
riches.  Many  of  these  voyagers,  as  Ogilby  (1671)  and  Benyowsky 
(1771),  enter  into  most  elaborate  details  concerning  the  auriferous 
wealth  of  Formosa.  Yet  the  knowledge  of  the  sites  of  the  old 
workings  had,  up  to  1890,  been  completely  lost.  In  that  year 
flakes  of  gold  were  discovered  during  the  construction  of  a  railway 
in  the  extreme  north  of  the  island.  Thousands  of  Chinese,  many 
of  whom  had  worked  placer  deposits  in  Australia  or  America, 
flocked  across  to  the  new  find.  At  first,  individual  miner's  rights 
were  issued  by  the  Chinese  authorities,  but  in  1893,  in  order  to 
lessen  the  expense  of  administration,  the  fields  were  farmed  out 
for  18  months  to  four  wealthy  Chinese  for  the  sum  of  £7,500  (75,000 
yen).a  In  that  year  a  rich  placer  deposit  was  discovered  in  the 
Kyu-fun  mountains,  and  the  fortunate  monopolist  who  possessed 
that  portion  is  believed  to  have  obtained  several  hundred  pounds 
sterling  daily  for  a  considerable  period.  The  number  of  washers 
engaged  was  very  large,  and  it  is  estimated  that  in  one  year  (1893 
to  1894)  as  much  as  £200,000  was  recovered.  In  1894  gold-quartz 
veins  were  discovered  at  Kyu-fun  by  a  Chinese  miner,  who  had 
obtained  some  experience  in  California,  and  in  the  same  year,  the 
Chinese  authorities,  in  view  of  the  flourishing  state  of  the  industry, 
resumed  direct  control.     The  island  passed  to  Japan  in  1895. 

The  principal  alluvial  fields  are  along  the  upper  waters  of  the 
Kelung  river,  for  20  miles  above  the  village  of  Suihenkiaka  (Long. 
121°  39'  E.  ;  Lat.  25°  05' N.).  Several  streams  flowing  north-east 
to  the  coast  from  the  Kyu-fun  hills  also  yield  alluvial  gold.  Zui-ho, 
9  miles  from  Kelung,  is  practically  the  centre  of  the  alluvial  district. 
Only  the  long-torn  and  the  cradle  have  as  yet  been  used  by  the 
native  washers.  Other  auriferous  gravels  or  veins  are  known  along 
the  precipitous  and  dangerous  east  coast,  access  to  which  is 
equally    difficult   by   sea  or  by   land.       These  are    in    the  Giran 


a  Davidson,  "  The  Island  of  Formosa,"  London,  1903,  p.  439. 


284 


ASIA. 


(Gilan)  district  ;  in  the  Buroko  district,  12  miles  south  of  Giran ; 
near  Shinjio,  35  miles  south  of  Suao  ;  near  Shukoran,  and  in  the 
extreme  south-west  of  the  island  in  the  Fuko  (Hongkong)  hills. 
A  reference  to  a  geological  map  of  Formosa  shows  that  the  above- 
mentioned  localities  are  more  or  less  coincident  with  exposures  of 
Tertiary  andesitic  rocks. 

The  only  vein  mines  now  being  worked  are  in  the  immediate 
vicinity  of  Zui-ho.  The  country  is  composed  of  Tertiary  sedi- 
mentary strata  intruded  by  andesitic  dykes."  Three  Japanese 
companies,  the  Fujita,  Tanaka,  and  Batanko,  are  at  work.  The 
Fujita  mines  are  at  Kyu-fun,  several  hundred  feet  above  sea-level. 
The  ore  occurs  in  a  highly-decomposed  zone,  and  is  so  soft  that  stamps 
have  not  hitherto  been  found  to  be  necessary.  The  zone  has  been 
traced  for  2,500  feet  and  varies  from  2  to  7  feet  in  width.  Within 
60  feet  of  the  ore  body  are  seams  of  workable  coal  in  the  Tertiary 
sedimentary  rocks.  Similar  coal  seams  are  worked  in  the  neighbour- 
hood to  furnish  motive  power  for  the  mines.  The  rainfall  of  the 
district,  150  inches  per  annum  falling  on  219  days,  is,  however,  so 
great  that  abundant  electric  power  is  readily  generated  from  the 
numerous  waterfalls.  The  mill  of  the  Fujita  is  on  the  coast,  6,000 
feet  distant  from  the  mine,  and  is  connected  with  it  by  an  aerial 
tramway.  In  1906  the  monthly  output  was  some  2,700  tons  for  a 
yield  of  2,150  ounces  bullion,   700  fine  in  gold. 

The  Tanaka  mines  are  two  in  number,  one  at  Kinkwaseki, 
and  the  other  at  Batanko.  The  output  is  about  2,000  ounces  per 
month. b  The  Kinkwaseki  mine  is  in  an  area  of  Tertiary  sandstone 
and  shale  intersected  by  a  large  dyke  of  quartz-andesite  running 
north  and  south.  The  vein  occurs  on  the  east  side  of  the  dyke 
and  sends  small  veinlets  into  it.  The  thickness  of  the  vein  is  in 
places  not  less  than  20  feet. 

A  little  to  the  south  of  the  two  principal  mines  the  Botanko 
mine  lies  in  similar  rocks.  In  1906,  1,000  tons  per  month  were 
being  treated  for  1,100  ounces  bullion,  900  fine,  but  the  output  was 
shortly  to  be  increased.  The  following  table  shows  the  yields 
of  the  respective  Formosan  mines  from  1903  to  1905  inclusive  : — 


Fujita  (Kyu-fun). 

Tanaka. 

Year. 

Kinkwaseki. 

Botanko. 

Ounces. 

Value. 

Ounces. 

Value. 

Ounces. 

Value. 

1903 
1904 
1905 

8,272 
21,360 
25,800 

£26,172 
64,730 
73,014 

12,559 
14,341 

24,800 

£50,836 
53,375 
85,312 

8,774 
12,641 
12,130 

£32,940 
47,738 
43,473 

a  "  Outlines  of  Geology  of  Japan,"  Tokyo,  1902,  p.  129. 

6  Crowe,  Consular  Reports,  Foreign  Office,  May,  1906,  Xo.  649. 


FORMOSA. 


285 


Placer. 

Total. 

"Year. 

Ounces. 

Value. 

Ounces. 

Value. 

1903 
1904 
1905 

9,239 
5,126 
3,447 

£28,976 
16,500 
11,030 

38,844 
53,468 
66,177 

£138,924 
182,343 

212,829 

The  total  yield  of  Formosa  from  1897  to  1907  inclusive  is  : — 


Year. 

Quartz. 

Allurial. 

Total  Ounces. 

Year. 

Quartz. 

Alluvial. 

Total  Ounces. 

1897 
1898 
1899 
1900 
1901 
1902 

1,322 

4,077 

11,087 

18,735 

27,893 

278 

867 

878 

1,136 

15,409 

20,424 

278 

2,189 

4,955 

12,223 

34,144 

48,317 

1903 
1904 
1905 
1906 
1907 

29,605 
48,342 
62,730 
48,051 
42,229 

9,239 
5,126 
3,447 
1,712 
1,328 

38,844 

53,468 

66,177 

49,763" 

43,557° 

353,915 

*  Value  about  75s.  per  ounce. 


FRENCH  INDO-CHINA. 

Tongking. — Gold  is  very  sparsely  distributed  in  Tongking, 
and  its  recovery  is  practised  only  on  the  smallest  of  scales.  The 
gold  occurrences  are  mainly  placer.  They  are  situated  at  Cam-Lan 
(Sontai  province),  Miat-Son  (Lao-kay  province),  at  various  spots 
in  the  Tuyen-Kwang  province,  and  at  Mai-duc  (Phuong-Lam 
province).  The  last  alone  calls  for  further  mention.  It  lies  some 
distance  south  of  Hanoi,  on  the  southern  border  of  the  alluvial 
delta  of  the  Red  river.  It  is  in  a  region  of  low  hills  composed  of 
slates  and  schists,  through  which  small  gold-quartz  veins  run. 
These  last  occasionally  assay  as  high  as  26  dwts.  gold  per  ton. 
Their  degradation  has  furnished  alluvial  deposits  containing  very 
fine  gold,  which  were  long  worked  by  the  Chinese.  Since  the 
occupation  of  the  country  by  the  French  the  placers  have  been 
abandoned." 


Annam. — As  in  Tongking,  the  auriferous  occurrences  of 
Annam  are  of  little  present  importance,  and  may,  with  two  excep- 
tions, be  dismissed  with  the  mere  indication  of  their  respective 
localities.  They  occur  at  Tuong-Dong  (Hatinh  province)  ;  to  the 
south  of  Turan  (Kwang-Nam  province)  ;  in  the  Mai-Leng  region 
(Kwang-Tri   province)  ;    and    at    Kim-Son    (Binh-Dinh    province). 

a  Pelatan,  "  Les  Rickesses  Minerales  des  Colonies  francaises,"  Paris,  1902,  p.  238. 


286  ASIA. 

Of  these,   the  Kwang-Nam  occurrences  are  alone  of  importance. 
Gold  is  found  both  in  veins  and  in  alluvial  gravels. 

The  actual  localities  at  which  gold  is  or  has  been  worked  are 
Vinh-Ninh,  Than-Hoa,  Vinh-Muy,  Tai-Yen,  and  Bong-Miu.  At 
the  last-mentioned  mines  the  ancient  workings  are  very  extensive, 
stretching  on  some  of  the  veins  for  a  mile  in  length.  These  mines 
were  taken  up  by  a  French  company  (La  Societe  des  Mines  d'Or  de 
Bong-Miu)  in  1896.  Their  mills  in  1902  were  treating  from  50  to  60 
tons  quartz  per  day.  The  residues  were  being  cyanided.  The 
country  is  a  micaceous  schist  in  which  several  bands  have  been 
mineralised  (with  pyrite  and  galena)  to  breadths  of  1  to  6  feet. 
The  bands  are  locally  lenticular.  The  gold  occurs  either  free  or 
contained  in  pyrite  and  galena.  Chalcopyrite  is  occasionally  present. 
The  average  tenor  of  the  ore  is  said  to  be  9  dwts.  per  metric  ton, 
while  the  total  costs  are  given  at  12s.  per  ton.  Silver  to  the  extent 
of  3  to  16  ounces  per  metric  ton  is  also  present.  In  1902  no  less 
than  745,000  tons  ore  were  said  to  be  in  sight." 

A  second  auriferous  region  in  Annam  is  that  which  lies  in 
the  upper  basin  of  the  Se-San,  an  eastern  tributary  of  the  Me- 
Khong,  and  falling  into  it  at  Stung-Treng.  Here  are  numerous 
alluvial  deposits  that  have  for  centuries  been  exploited  by  the 
Laos.  The  alluvial  pay-streaks  are  rarely  more  than  a  yard  in 
thickness.  They  are  occasionally  very  rich,  and  some  have  a  local 
value  of  2  to  2 \  dwts.  per  cubic  yard.  The  general  tenor,  however, 
appears  to  be  from  3  to  15  grains  per  cubic  yard.  As  a  rule,  the 
gold  is  fine,  but  nuggets  have  been  reported.  One,  indeed,  is  said 
to  have  weighed  65  ounces.  Native  washing  is  carried  on  in  bateas, 
the  gravel  being  extracted  from  the  pay-streak  by  numerous  pits 
placed  close  together.  Quartz-mining  in  the  old  schists  of  this 
district  is  conducted  by  a  French  company  at  Ruhleville  on 
pyritous  gold-quartz  veins  carrying  also  galena. 

The  gold  yield  of  French  Indo-China  is  small ;  during  1906 
only  1,412  ounces  (44  kg.),  worth  £5,960,  were  produced. 


SIAM. 

The  mountain  ranges  that  separate  the  valleys  of  the  Me-nam 
and  the  Nam-mun  tributary  of  the  Me-Khong  contain  the  few 
known  gold  occurrences  of  Siam.  The  principal  mines  are  those 
of  Sara-buri,  Bu-Khanun,  Kabin,  Srakeo,  Watana,  Chentabun, 
and,  further  to  the  east,  Sesupon.    All  are  therefore  grouped  about 

a  Pelatan,  loc.  cit.  sup.  ;  Saugy,  Bull    Soc.  de   Geol.  Comm.  de  Paris,  XXII,  1900, 
p.  626  ;  Id.,  Bull.  Com.  de  l'Asie  francaise,  X,  1902,  p.  346. 


SIAM.  287 

the  102nd  meridian  of  longitude,  and  to  the  east  and  south-east 
of  Bangkok. 

The  Bu-Khanun  mines,  south-east  of  Korat,  are  in  alluvial 
gravels  that  rest  on  sericite-schists.  Srakeo,  midway  between  Korat 
and  Chentabun,  contains  veinlets  in  granite  that  have  so  far  yielded 
most  disappointing  results  to  the  French  company  working  them. 
The  Watana  mines  are  also  worked  by  a  French  company.  They 
were  first  opened  as  placer  mines,  but  in  1894  an  exceedingly  rich 
pocket  was  found  in  a  quartz-vein  in  the  eruptive  porphyries  that 
traverse  the  crystalline  schists  of  these  mountains.  Since  that  time 
further  rich  pockets  have  been  encountered,  but,  taken  as  a  whole, 
the  deposits  offer  little  encouragement  to  systematic  exploitation. 
The  veins  of  Chentabun  are  also  in  decomposed  eruptive  rocks. 
They  have  been  worked  by  the  Siamese,  and  even  of  late  years 
have  yielded  rich  gold-quartz.  They  are  now  abandoned.  Similar 
veins  occur  at  Sesupon,  which  is  situated  on  a  river  flowing  into 
the  great  Tonle  Sap  lake.  The  Kabin  mine,  midway  between 
Pactum  and  Watana,  formerly  produced  more  than  2,000  ounces 
gold  per  annum. 

The  climate  of  the  Siamese  gold  districts  is  one  of  the  most 
deadly  and  most  malarious  in  the  world,  and  even  a  short  sojourn 
often  proves  fatal  to  native  and  to  European  alike.  This  fact,  of 
course,  militates  greatly  against  the  development  of  the  mines. 


FEDERATED    MALAY    STATES. 

In  this  portion  of  the  Malay  Peninsula  a  belt  of  auriferous  coun- 
try extends  northwards  from  Mount  Ophir  into  Kelantan.  Along 
the  belt  all  the  peninsular  goldfields  occur,  but  in  sparse  and  irregular 
distribution.  The  country  of  the  goldfields  is  essentially  the  Raub 
series  of  shales  and  limestones,  which  appear  to  correspond  very 
closely  with  the  Upper  Productus  beds  of-  the  Salt  Range  in  India," 
and  are  therefore  of  Permo-Carboniferous  age.  They  may,  however, 
on  examination  be  found  to  be  more  closely  allied  to  similar  beds 
in  the  Shan  States  of  Burma.**  Interbedded  with  the  limestones 
and  shales  of  the  Raub  series  are  tuffs  and  ash-beds,  which  are  often 
highly  sheared.  With  these  latter  may  possibly  be  connected  basic 
dykes  that  are  found  cutting  through  the  granite.  The  dykes  are 
both  diabasic  and  doleritic.  The  igneous  members  of  the  Raub 
series  are  sometimes  metamorphosed  into  hornblendic  and  augitic 
schists.    Garnetiferous  phyllites  are  also  found. 


a  Scrivenor,  Progress  Rep.  Geol.  Surv.  Fed.  Malay  States,  1907,  p.  25. 
b  Middlemiss/'Ann.  Rep.  Geol.  Surv.  India,  1900,  p.  138. 


288  asia. 

Kelantan. — The  semi-independent  State  of  Kelantan,  ruled 
by  a  Mussulman  sultan,  lies  in  the  Malay  Peninsula,  in  the  extreme 
south  of  Siam.  It  is  now  to  be  considered,  together  with  the 
adjacent  Trengganu  State,  as  a  portion  of  the  Federated  Malay 
States,  the  transfer  from  Siam  having  been  effected  in  1908.  Its 
auriferous  districts,  indeed,  lie  on  the  northern  slopes  of  those 
mountains  from  which  the  Plus  and  the  Kintra  rivers  flow  to  Perak. 
The  best  known  of  the  gold  mines  are  situated  at  Kundor  (Long.  101° 
55'  E. ;  Lat.  4°  54/  N.)  on  the  left  bank  of  the  Galas  river,  a  short 
distance  from  Pulai,  and  within  a  few  miles  of  the  Pahang  border. 
These  mines  have  been  worked  for  generations  by  the  Chinese  and 
Malays,  who,  however,  devote  the  whole  of  their  energies  to  the 
placer  deposits  of  the  neighbourhood/*  Successful  dredging  on 
the  Kelantan  river  has  been  carried  on  since  1904  by  the  Duff 
Development  Syndicate.  The  attempts  of  this  company  to  discover 
gold-quartz  veins  of  economic  value  have  so  far  met  with  failure. 
During  1904-5  this  company  produced  £4,931  ($42,264),  and  in 
the  following  year  £8,900  ($76,290)  gold,  all  derived  from  the 
dredges.  In  1906-7  the  dredging  companies  obtained  6,461  ounces 
gold.6 

Perak. — In  Upper  Perak,  Batang  Padang,  and  Kuala  Kangsar, 
gold  is  found  in  limited  quantities  with  the  tin  "  wash."  Near 
Tapah,  in  Batang  Padang,  a  gold-quartz  vein,  Bukit  Mas,  has 
been  worked  in  phyllite.  In  1897  it  produced  1,100  ounces  gold 
from  5,250  tons  ore.  It  has  since  been  abandoned.0  Perak,  in 
1905,  produced  1,799  ounces  (fine)  worth  £7,196,  and  in  1906, 
1,057  ounces  (fine)  worth  £4,228. 

Negri  Sembilan. — Gold  is  found  along  the  eastern  portion  of 
this  State  from  the  borders  of  Malacca,  in  the  Tampin  district, 
to  the  boundary  of  Pahang,  in  the  Kuala  Pilah  district.  Batu 
Bersawah,  lying  a  little  to  the  north  of  Mount  Ophir,  is  the  only 
gold-quartz  mine  now  being  worked  in  Negri  Sembilan.  Its  returns 
are  very  small,  being  in  1906  only  434  (fine)  ounces.  It  appears  to 
be  in  sheared  and  altered  diabase  near  its  junction  with  the  Raub 
shales. d  The  veinstone  is  quartz,  and  the  gold  occurs  with  pyrite 
and  blende.  The  auriferous  occurrence  at  Pasoh  in  the  north  of 
this  State  is  interesting  since  the  country  is  a  sheared  granophyre. 
There  is  no  defined  lode,  and  from  the  fact  that  the  richest  patches 
were  obtained    in  vughs  with   pyrites,  it    would  appear  that  the 

"Clifford,  Geog.  Jour.,  IX,  1897,  p.  33. 

6  Graham,  Cons.  Rep.,  1907. 

c  Belfield,  "  Handbook  of  Fed.  Malay  States,"  London,  1907,  p.  69. 

*  Scrivenor,  loc.  cit.,  p.  25. 


FEDERATED    MALAY    STATES. 


■2  S9 


free  gold  obtained  was  derived  from  the  decomposition  and  removal 
of  pyritous  impregnations. 

Pahang. — Alluvial  gold  in  small  quantities  is  widely  distri- 
buted throughout  Pahang.  None  of  these  placer  occurrences 
appear  to  be  worthy  of  the  attention  of  the  European  miner.  At 
the  present  time  gold-quartz  veins  are  worked  in  this  State  only  by 
the  Raub-Australian  Gold  Mining  Company,  which  controls  the 
three  mines,  Bukit  Koman,  Bukit  Malacca,  and  Stope.  The  rocks 
of  these  mines  are  the  shales  of  the  Raub  series,  here  almost  vertical. 
With  the  shales,  which  are  often  calcareous,  are  associated  calcareous 
crush-conglomerates.  There  are  no  well-defined  veins,  but  the  ore 
is  obtained  from  irregular  lenticular  bedded  veins  and  stringers, 
the  value  being  highest  where  there  is  a  considerable  admixture 
of  pyritous  country.  At  Bukit  Koman,  when  the  quartz  is  massive 
and  in  bulk,  its  average  value  may  be  2|  to  3  dwts.  When,  however, 
the  ore-body  becomes  a  mass  of  quartz  veinlets  and  stringers  its 
value  rises  to  12  to  20  dwts.  per  ton.  At  the  Stope  mine  scheelite 
occurs  with  the  gold  quartz.  The  Raub  mines  and  mills  are  worked 
by  electricity  generated  at  the  Senjam  river.  The  latest  available 
returns  from  these  mines  are  : — 


Year. 

Tons  Ore. 

Ounces  Gold. 

1905 
1906 

60,905 
69,139 

7,879-227 
9,995-192 

or  an  average  return  of  2-75  dwts.  per  ton  ore. 

Gold-quartz  veins  have  from  time  to  time  been  worked  in  other 
parts  of  the  State,  at  Silensing,  Tui,  Punjom,  and  Kechau.  At  Tui 
the  veins  occur  with  calcite  in  a  light-grey  limestone  ;  at  Punjom 
in  a  nondescript  rock  resembling  a  greisen  ;a  and  at  Kechau,  40 
miles  north  of  Raub,  the  hanging -wall  was  hard  black  limestone, 
while  the  footwall  was  a  sheared  ash-bed,  probably  of  the  Pahang 
Volcanic  Series.  Between  these  clearly-marked  walls  were  scattered 
masses  of  low-grade  ore.  A  crushing  of  1,380  tons  from  Kechau 
yielded  581-503  ounces,  equivalent  to  8'42  dwts.  per  ton. 

The  output  of  gold  from  Pahang  from  1890  to  1906  inclusive 
was  241,358  ounces,  of  an  approximate  value  of  £965,000.  From 
the  four  States  comprising  the  Federated  Malay  States  there  were 
produced  during  1905  and  1906  : — 


Year. 

Ounces. 

Value. 

1905 
1906 

11,453 
11,580 

£45,812 
46,320 

a  Scrivenor,  Pahang  Gov.  Gazette,  July,  1904,  p.  5. 
T 


290 


EAST   INDIAN    ARCHIPELAGO    AND    POLYNESIA. 


PHILIPPINE    ISLANDS. 

Gold-mining  is  a  very  ancient  industry  in  the  Philippines, 
and  gold  has  long  been  exported  from  thence  to  China  and  Further 
India.  The  export  naturally  attracted  the  attention  of  both  the 
Spaniards  and  the  Portuguese,  who  hoped  to  find  there  a  second 
Inca  hoard,  and  many  were  the  futile  endeavours  made  by  them  to 
discover  the  supposed  rich  deposits.  As  far  back  as  1572  the  well- 
known  mines  of  Paracale  and  Mambulao  in  Camarines  Norte  were 
examined  by  Latin  adventurers.  It  follows,  therefore,  that  the 
more  accessible  alluvial  and  vein  gold-deposits  are  now  exhausted, 
leaving  only  those  which,  from  difficulty  of  access  or  of  working, 
were  beyond  the  reach  of  the  native  miners,  who,  as  in  the  case 
of  the  northern  Igorrotes,  indeed  displayed  no  mean  skill  in  vein- 
mining. 

In  the  island  of  Luzon  are  two  main  auriferous  districts.  The 
northern  field  lies  in  the  neighbourhood  of  Mount  Data  and  in  the 
country  of  the  Igorrotes  in  the  provinces  of  Abra,  Bontoc,  Lepanto, 
and  Benguet.  The  region  is  one  of  crystalline  schists  and  old  massive 
rocks.  The  placers  of  Nueva  Ecija  lie  north  of  Manila  and  east  of 
the  Rio  Grande  de  Pampanga.  They  have  long  been  worked  by  the 
natives,  but  were  only  recently  known  to  Europeans.  The  aurif- 
erous gravels  lie  on  sedimentary  rocks,  but  hornblende-andesite  and 
gneiss  are  known  in  the  neighbourhood.  The  pay-gravel  contains 
large  pebbles  and  masses  of  chalcedony  and  jasper.  The  gold  is  very 
pure,  but  is  small  and  flaky.  The  presence  of  clay  and  the  lack 
of  a  regular  water-supply  tend  to  hinder  the  exploitation  of  these 
placers.  Platinum,  and  possibly  iridium,  are  associated  with  the 
gold/'  The  southern  field  is  in  the  province  of  Camarines  Norte,  to 
the  east  of  Manila.  Here  also  the  region  is  gneissic  and  schistose. 
The  gold-quartz  veins  carry,  in  addition  to  gold,  pyrite,  chalcopyrite, 
galena,  and  sphalerite,  with  occasionally  a  little  lead  chromate 
(crocoisite).  At  Dagupan,  south-west  of  Mambulao,  are  numerous 
gold-quartz  stringers  in  black  clay-slates,  the  whole  being  strongly 
reminiscent  of  the  Southern  Appalachian  quartz  veins  in  saprolite/' 


a  Goodman,  Min.  Jour.,  Oct.  26,  1907. 

b  Becker,  20th  Ann.  Rep.  U.S.  Geol.  Surv.,  1S99-1900,  Pt.  Ill,  p.  576. 


PHILIPPINE     ISLANDS.  291 

At  Paracale,  die  rock  appears  to  be  granitic,  and  the  veins  are 
sometimes  20  feet  in  width.  From  1893  the  "Philippines  Mineral 
Syndicate  "  worked  the  historic  Mambulao  mines,  but  apparently 
with  little  success.  Numerous  placer  mines,  and  also  beach  sands, 
are  worked  in  the  Camarines  Norte  province,  but  their  production 
is  diminishing  from  decade  to  decade,  and  they  present  no  features 
of  special  interest.  Gold  dredges  were  operating  in  1907  on  the 
placer  deposits  of  Paracale. 

On  Masbate  Island  both  quartz  veins  and  placer  deposits  are 
being  worked.  At  Arroroy,  a  10-stamp  mill  was  erected  to  crush 
gold  quartz.  Two  gold  dredges  are  also  in  operation,  one  on  the 
Lanang  river  and  the  other  on  the  Guinibattan  river.  Both  are 
working  regularly/1 

In  the  province  of  Capiz,  Panay  Island,  several  alluvial  deposits 
are  worked.  The  best  of  these  appears  to  be  at  Astorga,  Dumarao 
{Lat.  11°  16'  N.).  Others  are  near  San  Enrique  and  Barotoc  Vie  jo 
in  the  province  of  Ilo-ilo.  In  the  island  of  Cebu  are  abandoned 
mines,  in  which  pyritous  veinlets  in  diorite  had  been  worked.  Gold 
occurs  at  Pambujan,  in  the  island  of  Samar.  Pyritous  gold-quartz 
veins  are  also  known  at  Pihutan  in  the  small  island  of  Panaon, 
lying  between  Leyte  and  Mindanao.  The  wall  rock  is  "  greenstone- 
porphyry."  One  vein  of  a  tenor  of  25s.  to  30s.  per  ton,  6  feet  wide, 
and  carrying  pyrite,  galena,  and  zinc-blende,  had  been  worked 
to  a  considerable  extent. 

Like  Luzon,  Mindanao  possesses  two  distinct  auriferous  regions, 
one  immediately  south  of  the  Bay  of  Macajalar,  in  the  province  of 
Misamis  (Lat.  8°  20'  N.  ;  Long.  120°  40'  E.),  the  other  including 
the  east-coast  range  of  the  province  of  Surigao.  The  Misamis 
deposits  include  veins,  placers,  and  river  sands.  The  veins  are 
mainly  in  the  Pigholugan  region,  where  the  two  principal  mines  are 
the  Abaca-an  and  the  Pigholugan.  Both  are  working  in  a  soft 
grey  argillaceous  slate,  where  numerous  narrow  quartz-stringers, 
rarely  more  than  an  inch  wide,  form  stockworks.  The  gold  occurs 
in  "  pockets,"  mainly  at  the  intersections  of  these  veinlets,  and 
the  method  of  working  is  governed  entirely  by  the  manner  of 
occurrence. ^  The  river  sands  of  the  region  are  little  worked,  and 
the  bulk  of  the  gold  comes  from  old  high-level  river  gravels,  of  which 
the  more  important  are  those  of  the  Iponan,  Rio  Cagayan,  Bigaan, 
and  Cutman  (Kugman),  all  rivers  flowing  into  the  Bay  of  Macajalar. 
The  pay-streak  in  the  gravels  runs  from  18  inches  to  10  feet  in 
thickness,  and  appears  to  average  about  5  feet.  According  to 
Abella,  the  pay-streak  contains  as  much    as  27  grains  fine  gold  per 


a  Eng.  Min.  Jour.,  July  21,  1906,  p.  102. 

6  Nichols,  Trans.  Inst.  Amer.  M.E.,  XXXI,  1901,  p.  612. 


292  EAST    INDIAN    ARCHIPELAGO. 

cubic  yard,"  yet  those  engaged  in  washing  earn  only  from  6d.  to 
Is.  per  day.  Nichols''  estimates  the  value  of  the  dredging  area  of 
the  Iponan,  below  the  Pigtao,  as  worth  from  7  id.  to  12|d.  (15  to 
25  cents)  per  cubic  yard. 

In  the  Surigao  province  the  eastern  mountains  are  reported 
to  be  auriferous  from  their  northern  extremity  as  far  south  as 
Carga  (7°  12'  N.).  The  northern  portion  appears  to  be  the  richer, 
especially  in  the  neighbourhood  of  Surigao,  Placer,  Mainit,  and  Taga- 
nan.  The  gold-quartz  veins  of  this  area  are  pyritous  (pyrite, 
chalcopyrite,  galena,  and  blende),  and  lie  in  a  metamorphic  slate. 
They  are  small  and  pockety,  resembling  greatly  those  of  Pigholugan 
described  above.  Beside  the  foregoing  there  are  numerous  auriferous 
occurrences,  both  in  veins  and  in  gravels,  but  none  appear  at  the 
present  time  to  be  of  economic  value  or  of  scientific  interest. 

Gold  has  recently  been  found  about  25  miles  north  of  Zam- 
boanga,  at  the  westernmost  extremity  of  Mindanao.  It  occurs  in 
a  yellow  clay  arising  from  the  decomposition  of  a  schist,  the  original 
locus  of  the  gold  being  quartz-stringers  in  the  schist  .c 

BORNEO. 

British  North  Borneo. — Gold  has  been  known  since  1883 
in  the  gravels  of  the  Segamah  river  on  the  east  coast  of  North  Borneo. 
Silam,  in  Darvel  Bay,  is  the  nearest  port  to  the  locality.  Exploration 
in  the  neighbourhood  has  hitherto  failed  to  prove  the  existence 
of  gold  in  payable  quantities.  Beach  gold  is  also  reported  from 
Marudu  Bay. 

Sarawak. — The  gold  deposits  of  economic  importance  in  this 
State  lie  to  the  south-west  of  Kuching,  the  capital.  They  were 
worked  both  for  alluvial  gold  and  for  lode  gold  by  the  Chinese. 
The  placer  gravels  are  now  more  or  less  exhausted.  It  was  from 
Krian,  near  Bau,  that  the  largest  nugget  found  in  the  Borneo  drifts 
was  obtained.     Its  weight  was  7  ounces  (218  grammes). d 

Gold  is  won  from  the  matrix  at  Bau,  Bidi,  and  Jambusan, 
about  15  miles  south-west  of  Kuching.  The  Bau  mines  were 
primarily  worked  for  antimony.  The  general  geology  of  the  country 
is  simple.  A  conformable  series  of  stratified  rocks  lies  approximately 
horizontal.  The  basement  rock  is  a  Middle  Oolite  limestone,  which 
is  overlain  by  thin  marl  beds,  often  very  local  in  development. 
The  marl,  where  it  occurs,  is  overlain  b}~  a  series  of  shales,  sandstones, 
grits,  and  conglomerates.     The  whole  series  is  greatly  broken  by 

a  Becker,  loc.  cit.,  p.  581. 

h  Loc.  cit.,  p.  616. 

'  Min.  Sci.  Press,  Jan.  1,  1908. 

d  Posewitz,  "  Borneo,"  Trans.  F.  H.  Hatch,  London,  1902,  p.  318. 


SARAWAK.  293 

block-faulting,  and  is  extensively  intruded  by  quartz-porphyry 
dykes. a  The  igneous  rocks  also  occur  as  sills  and  as  nondescript 
masses  or  stocks  varying  in  character,  according  to  Scrivenor, b 
from  a  hypersthene-gabbro  to  a  quartz-diorite.  All  are  probably 
segregations  from  an  andesitic  magma. 

The  main  gold-bearing  belt  of  Upper  Sarawak  may  be  said  to 
extend  from  south-west  to  north-east  through  Bau  and  Bidi.  The 
ore  occurs  :  (a)  As  irregular  masses  in  limestone,  and  (b)  as  impreg- 
nations or  disseminations  in  shale.  The  former  are  as  a  rule  richer 
and  more  pyritous  than  the  latter.  At  Bau  the  workings  are  all 
open-cast,  and  are  scattered  over  a  wide  area  of  low-lying  land. 
The  ore  is  a  dark  breccia  of  shale,  sandstone,  and  limestone  cemented 
and  often  largely  replaced  by  silica.  The  minerals  associated  with 
the  gold  are  strikingly  characteristic  of  andesitic  influence.  They 
are  mispickel,  galena,  proustite,  cinnabar,  native  arsenic,  realgar, 
native  antimony,  stibnite,  senarmontite,  valentinite,  jamesonite, 
and  bindheimite  (lead  antimoniate).  The  gold  (as  at  Coromandel, 
New  Zealand)  is  often  associated  with  native  arsenic,  while  the 
stibnite  contains  little  or  no  gold.  The  pyritic  ore  from  Su  San 
Shien,  Bau,  yielded  on  analysis  (Geikie)  : — 

Sulphur      

Arsenic       

Iron 

Copper        

Lead 

99-64 

At  this  mine  it  has  been  noted  that  where  intrusive  sills  occupy 
a  horizontal  position  in  the  shales,  mineralisation  is  wholly  confined 
to  the  underlying  beds  of  shale.  While  the  shales  overlying  the 
limestone  are  often  auriferous,  the  marls  that  have  already  been 
mentioned  as  having  a  local  development  are  always  barren.  The 
gold  comes  from  the  pyrites  in  the  shales,  no  free  gold  being  seen, 
even  in  panning  rich  ore.  Silicified  shales  furnish  the  great  bulk 
of  the  ore  milled.  In  these,  the  impregnation,  as  might  be  expected, 
is  extremelv  irregular  in  value.  Average  analvses  of  silicified  ore 
gave  the  following  : — 


31-75 

Zinc 

14-32 

20  32 

Cobalt         

•30 

27-86 

Silica           

•84 

•04 

Oxygen  and  Loss 

11 

4-10 

Silica 

...                     •  •  * 

76-82 

to 

85-59 

Arsenic 

...                      •  .  • 

1-14 

>j 

14  84 

Antimony 
Iron  ... 

-50 

-94 

it 
n 

1-50 
2  05 

Sulphur 
Lime... 

:>4 

-89 

1-75 
5  60 

Carbon  di- 

oxide 

-70 

ii 

4-44 

Gold... 

S  dwts.  to  35  dwts.  per  ton. 

Silver 

20      „       ,.   40     „ 

n 

a„Geikie,  Trans.  Inst.  Min.  Met.,  XV,  1905,  p.  63. 

b  "Geology  of  Sarawak,"  Sarawak  Gazette,  1905,  p.  102. 


294  EAST    INDIAN    ARCHIPELAGO. 

At  Taiton  the  ore  occurs  in  fissures  in  the  limestone,  but  mud, 
clay,  and  soil  have  also  been  worked.  There  would  appear  to  be 
often  a  secondary  enrichment  near  the  surface,  probably  effected 
in  this  case  by  the  removal  of  matrix  and  base  matter. 

At  Jambusan,  2  miles  east  of  Bau,  the  ore  occurs  as  irregular 
masses  or  pockets  in  the  limestone.  The  ore-bodies  have  no  well- 
defined  limits,  and  their  exploitation  is  guided  entirely  by  the 
tenor  of  the  rock.  The  ore  is  a  hard,  black,  cherty  rock,  containing 
87  per  cent,  silica  and  11  per  cent,  stibnite.  The  gold  is  coarse 
and  free,  varying  in  amount  from  5  dwts.  to  20  ounces  per  ton  of 
ore.  Numerous  dykes  and  intrusive  sheets  occur  in  this  neighbour- 
hood, and  it  is  evident  that  the  mineralisation  throughout  this 
field  is  closely  dependent  on  these  igneous  rocks.  Near  Bau,  a 
quartz-porphyry  dyke  yields  from  U  to  2  dwts.  per  ton,  and  there 
are  several  similar  dykes  in  the  neighbourhood  whose  gold  content 
appears  to  be  associated  with  wad  and  manganiferous  clay. 

At  Tai  Parrit,  about  100  acres  are  silicified  and  mineralised, 
carrying  small  quantities  of  gold  throughout.  Shales,  lime- 
stones, and  marls  are  confusedly  thrown  together,  and  the  whole 
is  intruded  by  numerous  dykes.  In  some  cases  brecciation  is  due 
to  removal  of  the  underlying  limestone,  in  others,  it  is  apparently 
due  to  faulting.  As  a  rule,  the  deposits  are  small,  scattered,  and 
shallow,  but  at  Jambusan  one  deposit  has  been  proved  to  a  depth 
of  120  feet. 

Since  mining  is  open-cast  the  costs  are  low.  Mining  and 
transport  amounted  in  1905  to  2s.  6d.  per  ton,  while  the  total  costs 
were  10s.  4d.  per  ton.0  From  November,  1898,  to  July  31st,  1904, 
no  less  than  448,319  tons  ore  had  been  treated  at  Bau  for  a  yield 
of  87,182  ounces  fine  gold,  equal  to  a  return  of  3-88  dwts.  per  ton. 
In  1905,  two  mills,  at  Bau  and  Bidi,  were  in  operation,  the  former 
treating  10,000  and  the  latter  8,000  tons  per  month.  The  output 
of  fine  gold  in  1905  was  44,299  ounces,  39,180  ounces  in  1906,  and 
41,751  ounces  in  1907. 


DUTCH    EAST    INDIES. 

Dutch  Borneo. —Gold  has  for  centuries  been  worked  in 
Borneo  by  the  Chinese,  who  operated,  generally  with  great  success, 
in  small  working  syndicates.  In  the  early  part  of  the  nineteenth 
century  the  Chinese  industry  was  in  a  highly-flourishing  condition, 
and  Chinese  miners  were  possessed  of  considerable  political  influence, 
the  exercise  of  which  eventually  brought  them  into  conflict  with 

a  Scrutton,  Trans.  Inst.  Mm.  Met.,  XV,  1905,  p.  144. 


DUTCH   EAST    INDIES.  295 

the  Dutch  authorities,  and  engendered  a  long  war  that  ended  only 
in  1854  with  the  complete  subjugation  of  the  Chinese.  During 
the  struggle  the  gold-mining  industry  suffered  severely,  and  has 
never  indeed  regained  its  former  position.  In  Dutch  Borneo,  gold 
occurs  both  in  the  parent  rock  and  in  the  gravels  of  the  streams, 
nearly  all  of  the  latter  containing  a  little  gold.  Three  main 
auriferous  districts  may  be  made  out  :  a  western,  including  the 
so-called  "  Chinese  districts  "  in  the  neighbourhood  of  the  Sambas 
and  Landak  rivers  ;  a  central  district  covering  the  country  at  the 
heads  of  the  Kahajan  and  the  Kapuas  rivers  ;  and  a  south-eastern 
district  including  the  Tanah-Laut  and  the  Kusan  countries.  The 
line  of  auriferous  country  in  Borneo  would  therefore  appear  to  strike 
from  Western  Sarawak  south-east  across  Central  Borneo  to  Tanah- 
Laut,  a  line  coinciding  very  closely  with  the  distribution  of  the 
Tertiary  eruptive  rocks,  as  shown  on  Posewitz's  geological  map.a 
No  gold-quartz  veins  of  importance  have  yet  been  found  in 
Dutch  Borneo,  though  many  have  from  time  to  time  been  worked 
by  the  Chinese.  The  western  district  contains  the  majority  of 
those  known.  There,  Von  Schelle  found  numerous  vein-like  impreg- 
nations in  the  phyllites,  slates,  and  sandstones  of  the  "Old  Slate" 
(Devonian  ?)  formation,  or  in  the  older  igneous  rocks  (granite  and 
porphyrite).  The  latter,  as  well  as  the  former,  are  often  highly 
metamorphosed.  The  more  noteworthy  of  these  occurrences  of 
the  western  district  are  in  the  Skadau  mountains  ;b  in  the  Udu 
mountains,  further  to  the  south-east  near  Melassam  ;  near  Sjui- 
Tsiet  on  the  northern  slopes  of  the  Pandan  mountains  ;  near 
Mandor  in  the  Han-ui-san  and  Snaman  mountains  ;  and  near 
Sikarim.  Both  the  older  sedimentary  rocks  and  the  intrusive 
granites  and  diorites  are  traversed  by  younger  apparently  Tertiary 
dykes  of  andesitic  facies.  The  occurrence  of  gold  is  more  or  less 
restricted  to  the  igneous  rocks,  to  their  contacts,  or  to  the  slates 
near  the  point  of  contact.0  The  period  of  auriferous  deposition 
generally  would  seem  to  be  post-Eocene  and  to  have  been  dependent 
on  the  early  Tertiary  eruptions.  A  vein  near  Budok  is  especially 
interesting,  in  that  it  contains  sylvanite  (telluride  of  gold  and  silver), 
the  only  occurrence  of  this  mineral  yet  reported  from  Borneo.  The 
usual  associates  of  the  gold  are  pyrite,  chalcopyrite,  and  galena. 
The  alluvial  deposits  of  the  western  district  have  derived  their  gold 
directly  from  the  denudation  of  veins  and  veinlets  similar  to  those 
above  described.  The  deposits  in  the  lowest  portion  of  the  beds  of 
the  present  rivers  have  not  yielded  much  to  the  native  worker 

a  "Borneo,"  Theodor  Posewitz,  Trans.  F.  H.  Hatch,  London,  1902,  p.  312  et  seq. 

b  Loc.  cit.,  p.  334. 

c  Truscott,  Trans.  Inst.  Min.  Met.,  X,  1902,  p.  58. 


296  EAST   INDIAN   ARCHIPELAGO. 

owing  to  the  great  quantities  of  water  encountered.  They  may  be 
found  to  be  well  adapted  for  dredging.  Native  alluvial  workings 
have  been  mainly  carried  on  in  the  older  drifts  where  the  gold  has 
been  found  associated  with  diamonds,  platinum,  and  cinnabar. 
These  older  drifts  are  probably  Quaternary.  The  soil  of  the  hill- 
slopes  also  furnishes  gold  that,  in  this  case,  is  liberated  from  the 
matrix  by  the  decomposition  of  the  rock  in  situ.  Such 
deposits  are  of  course  poorer  than  those  on  which  the  concen- 
trating power  of  running  water  has  had  some  play.  Native  washing 
is  effected  with  rude  ground  sluices  and  bateas.  Chinese  washing 
is  much  more  advanced,  water-wheels  and  chains  being  used,  and 
long  water-races  dug  to  bring  in  water  to  command  the  gravels. 

The  central  auriferous  district  lies,  as  has  been  stated,  towards 
the  head- waters  of  the  Kahajang  and  the  Kapuas.  The  Kahajang 
mine  is  the  most  noteworthy.  It  is  at  the  contact  of  a  quartz- 
porphyrite  with  the  "  Old  Slate  "  formation,  both  having  been 
fractured  and  impregnated  with  silica  and  auriferous  pyrites."  The 
quartz  of  the  porphyrite  is  blue  or  purple,  and,  with  the  felspar,  often 
assumes  a  peculiar  lenticular  shape,  the  result  apparently  of  pressure. 
The  main  Kahajang  veins  are  about  212  feet  apart,  with  several 
small  veinlets  in  the  intervening  country.  The  quartz  assays 
about  an  ounce  gold  and  12  dwts.  silver  per  ton.  A  small  trial 
crushing  of  139  tons  gave  260  ounces  bullion,  780  fine.  Other  quartz- 
veins  in  the  neighbourhood  are  in  quartz-porphyrite  or  felsite 
dykes,  and  from  the  degradation  of  these  the  alluvial  gold  appears 
to  have  been  derived.  As  in  the  western  district  there  is  a  great 
development  of  Tertiary  andesites,  dacites,  rhyolites,  and  basalts. 
These  are  especially  well  developed  in  the  Miiller  mountains,  where 
they  appear  to  be  disposed  along  a  line  of  fractured  Auriferous 
impregnation  here  also  is  apparently  dependent  on  the  volcanic 
rocks.  The  alluvial  deposits  of  the  Kahajang  Valley  appeared  to 
Truscott  to  afford  scope  for  dredging. 

In  the  south-eastern  district  no  quartz  veins  have  been  located, 
but  the  alluvial  gold,  especially  near  Amuntai,  appears  to  have  been 
derived  from  an  altered  andesite.  On  the  whole,  the  Tanah-Laut 
district  in  the  extreme  south-east  of  Borneo  has  furnished  the 
richest  alluvial  deposits. 

The  gold  yield  of  Dutch  Borneo  is  insignificant,  being  only 
1,990  ounces  (62  kg.)  in  1905,  and  1,059  ounces  (33  kg.)  in  1906. 

Celebes.— Gold-mining  on  the  island  of  Celebes  is  at  present 
confined  to  the  narrow  east  and  west  peninsula  in  the  northern 

a  Truscott,  loc.  cit.  sup. 

"  Molengraaff,  "  Geological  Explorations  in  Central  Borneo,"  London,  1902. 


CELEBES.  297 

extremity  of  the  island.  Here  natives  and  Chinese  have  long 
carried  on  the  industry  in  the  usual  crude  eastern  fashion.  As  in 
Sumatra  and  Borneo,  auriferous  deposition  appears  to  be  closely 
connected  with  rocks  of  andesitic  facies.  The  most  westerly  field 
on  the  north  coast  is  that  of  Palehleh.  These  mines  were  taken 
up  by  Europeans  in  1892,  and  eventually  passed  to  the  Nederland- 
Indische  Gold-mining  Company.  The  main  ore-body  consists  of 
veins  and  stringers  of  auriferous  sulphides  in  augite-porphyrite 
breccia."  Not  far  to  the  west  are  older  slates  intruded  by  por- 
phyrite  dykes.  The  slates  are  the  Dolakapa  series  of  MolengraafiV' 
The  porphyrite  dykes  are  pyritous,  and  are  occasionally  auriferous 
to  the  extent  of  1  to  1J  dwts.  per  ton.  The  ore-body  carries 
three  or  four  parallel  sulphide  veins  separated  by  country 
through  which  smaller  stringers  ramify.  The  width  mined 
varies  from  1  to  20  feet  and  will  probably  average  about 
6  feet.c  The  sulphides  of  the  ore-body  are  pyrite,  galena, 
sphalerite,  and  chalcopyrite,  with  small  quantities  of  antimony 
and  arsenic,  the  two  last  appearing  only  in  chemical  analyses. 
The  country  itself  is  also  thoroughly  impregnated  with  pyrites, 
and  is,  within  the  lode  limits,  auriferous  to  the  extent  of  2  dwts.  per 
ton.    The  sulphides  themselves  carry  :  — 


Gold 

4J  ounces  per  ton 

Silver 

12 

Lead 

8-5  per  cent. 

Copper 

1-5       „ 

Zinc 

3-5       „ 

The  value  of  the  ore,  owing  to  the  large  admixture  of  country, 
is  generally  however  about  -J  ounce  gold  per  ton  associated  with 
8-5  per  cent,  sulphides.  The  gold  is,  on  the  whole,  coarse,  and  lies 
upon,  rather  than  in,  the  pyrites  crystals,  from  which  the  bulk  of  it 
may  be  separated  by  grinding  and  washing.  A  proportion  seems  to 
be  more  closely  associated,  since  the  pyrites  thus  washed  away 
possesses  a  constant  value  of  an  ounce  per  ton.  The  Palehleh  ore- 
bodies  appear  to  be  disposed  at  intervals  along  a  fracture  plane, 
the  length  of  ore-bearing  shoots  being  more  or  less  equal  to  that  of 
the  intervening  barren  rock.  A  similar  occurrence  to  that  of 
Palehleh  lies  to  the  south  near  Pagoeat. 

Forty  miles  west  of  Palehleh,  at  Soemalatta,  also  on  the  north 
coast,  lies  a  similar  occurrence.  Here  the  ore-body,  rich  in  the 
andesite,  decreases  appreciably  in  value  as  it  passes  into  the  adjacent 
Dolakapa   slates.      The   eruptive    rocks    enclosing    the    ore-bodies 

a  Bucking,   "  Beitrage   zur  Geologie   von  Celebes,"     Petermann.     Geog.   Mittheil., 
XLV,  1899,  p.  276. 

6  Zeit.  fur  prakt.  Geol.,  1902,  p.  250. 

c  Truscott,  loc.  cit.  sup.,  p.  64. 


298  HAST  INDIAN  ARCHIPELAGO. 

are  diabase-  and  augite-porphyrite  breccia,  termed  by  Molen- 
graaff  the  "  Wubudu  eruptive  breccias.""  Three  main-reef  systems 
occur  at  Soemalatta  :  the  North  Reef,  South  Reef,  and  the  Veta 
Nueva.  Ten  miles  to  the  west,  beyond  Soemalatta,  is  a  vein  in 
the  eruptive  andesitic  breccia  of  Denuki  Bay.  The  lode-matter  is 
a  brecciated  rock  with  a  siliceous  cement,  highly  pyritous,  but 
of  low  value. 

On  the  opposite  coast  and  east  of  Soemalatta  is  Totok,  perhaps 
the  most  interesting  of  North  Celebes  auriferous  deposits.  Here 
the  gold  occurs  in  quartz  blocks  embedded  in  a  tough  clay  contained 
in  a  limestone  resting  on  porphyrite  (altered  andesite).  The  igneous 
rock  is  possibly  an  intrusive  sill,  while  the  clay  represents  the 
decomposition  product  of  brecciated  andesitic  dykes  that  have 
passed  upward  through  the  limestone.  Decomposition  has  been 
largely  accompanied  by  silicification.  The  gold  is  found  as  specks 
or  leaves  between  the  larger  quartz  crystals,  or  as  moss-  or  wire- 
gold  on  the  smaller  crystals.  Quartz  veinlets  ramifying  into  the 
limestone  are  small,  but  are  often  very  rich.  There  is  a  complete 
absence  of  sulphides,  and  these  veins  therefore  are  in  marked 
contrast  to  other  North  Celebes  occurrences.  From  the  geological 
evidence  afforded  at  Totok  the  general  period  of  andesitic  eruption 
and  of  auriferous  impregnation  is  almost  certainly  Tertiary. 

Six  miles  south-west  of  Totok  is  the  Kotaboenan  field,  where 
the  gold  occurs  associated  with  veinlets  and  impregnations  of  quartz 
and  sulphides  in  decomposed  andesite.6  Except  for  the  greater 
abundance  of  quartz  at  Kotaboenan,  the  geological  conditions 
resemble  those  of  Palehleh.  Minor  occurrences  are  found  at  Pinogo 
and  Gorontalo  further  to  the  south-Avest.'' 

In  1906  the  Celebes  goldfields  produced  25,038  ounces  (780  kg.) 
fine  gold,  Totok  yielding  11,716  ounces  (365  kg.),  Palehleh  9,598 
ounces  (299  kg.),  and  Soemalatta  3,724  ounces  (116  kg.). 

Sumatra. — From  the  remotest  times  Sumatra  has  been  famed 
for  its  gold.  Even  in  the  Ramayana,  one  of  the  two  great  Sanskrit 
epics  of  the  Hindus,  Yawadwipa  (Sumatra),  "  adorned  by  seven 
kingdoms,  the  gold  and  silver  region  rich  in  gold  mines"  is  mentioned. 
Yet,  at  the  present  day,  only  one  goldfield  is  certainly  known  to 
merit  the  application  of  modern  methods.  This  is  the  Radjang- 
Lebong  field,  100  miles  from  Bengkoelen  on  the  south-west  coast. 
Ancient  workings  were  discovered  in  1896,  and  work  has  since 
been  profitably  continued.     The  Radjang-Lebong  lode  consists  of 

a  Loc.  cit.,  p.  27G. 

"  Truscott,  loc.  cit.  sup. 

c  For  detailed  information  concerning  the  gold  deposits  of  the  Dutch  East  Indies, 
r.  Jaarbock  van  het  Mijnwezen  in  Xederlandsch  Oost-Indie,  Batavia,  1895-K06. 


SUMATRA. 


299 


five  Avell-defined  seams  separated  by  highly-silicificd  altered 
andesite.  A  blue  quartz  vein,  2  feet  wide,  on  the  footwall  carries 
1  to  2\  ounces  gold.  Then  a  band  of  silicified  andesite  18  to  25  feet 
wide,  assays  6  dwts.  throughout,  and  above  the  broad  band  of 
country  come  the  minor  seams. a  The  average  width  of  the  ore-body 
for  a  distance  of  1,000  feet  has  been  stated  at  17  feet.6  In  1908 
the  ore  reserves  were  said  to  be  265,000  tons  of  an  average  assay 
value  of  21  dwts.  gold  per  ton.  The  gold  is  finely  disseminated 
throughout  the  mass  and  can  rarely  be  seen  on  panning.  The 
common  sulphides  are  pyrite  and  chalcopyrite.  Pyrolusite,  wad, 
and  chalcopyrite  also  occur.  The  bullion  contains  (as  at  Waihi, 
New  Zealand)  a  notable  proportion  of  selenium,  an  analysis 
giving  :  — 

-48 

14 


Gold  and  Silver 

.     9152 

Zinc 

Selenium 

435 

Iron 

Copper    

Lead        

1-82 
1  65 

99-96 


No  tellurium  has  as  yet  been  detected  either  in  the  bullion  or  in  the 
ore.     The  ratio  of  silver  to  gold  in  the  bullion  is  often  10 : 1. 

At  Lebong  Soelit,  5  miles  west  of  Redjang  Lebong,  is  a  very 
similar  occurrence.  Four  outcrops,  suggesting  separate  parts  of  a 
faulted  vein,  have  been  worked  by  the  natives.  The  total  length 
of  outcrop  thus  indicated  is  2,000  feet,  over  which  the  reef  has 
an  average  width  of  8  feet  and  a  value  of  20  dwts.c  Assays  of  the 
enclosing  andesitic  country  have  yielded  a  little  silver  but  no  gold. 

A  third  gold-bearing  ore-body  lies  7  miles  west  of  Lebong  Soelit. 
The  three  occurrences,  Redjang  Lebong,  Lebong  Soelit,  and  the 
third  unnamed,  lie  along  an  east-west  line  12  miles  long. 

The  following  shows  the  output  of  the  Redjang-Lebong  mines 
during  the  years  1906  and  1907  :— d 


Gold. 
Ounces. 

Silver. 
OunCe*. 

Tons  Crushed. 

1906 
1907 

45,470 
59,926 

248,240 
327,584 

59,208 

In  1907  a  dividend  of  71  per  cent,  on  a  capital  of  £208,333 
(florins  2,500,000)  was  paid. 

The  Ketahoen  mines  are  also  in  the  Lebong  district  in  the 
south-west  of  Sumatra,  and   about  80  miles  north   of  Bengkoelen. 


a  Ivey,  Trans.  Inst.  Min.  Met,  XII,  1903,  p.  340. 

b  Truscott,  ib.,  X,  1902,  p.  53. 

c  Truscott,  loc.  cit.,  p.  55. 

d  Min.  Jour.,  Feb.  29,  1908,  p.  250. 


300  EAST    INDIAN   ARCHIPELAGO. 

Like  the  Redjang-Lebong  they  have  proved  extremely  profitable. 
During  1906  and  1907  they  yielded  gold  and  silver  to  the  value  of 
£64,710  (florins  783,000),  and  £83,718  (florins  1,013,000)  respectively. 

A  minor  auriferous  area  is  the  Oembilien  goldfield  in  the 
neighbourhood  of  Fort  de  Kock  and  Soepajang,  in  the  middle  of 
Sumatra.  The  country  here  is  also  andesitic,  but  the  quartz- 
veins  yet  found  have  been  of  very  low  grade.  In  the  old 
schists  of  Moera  Supongi  (Tapanoeli),  Western  Sumatra, 
Hundeshagen"  found  gold  in  a  grossularite  garnet  deposit 
with  wollastonite.  Black  augite-diorite  occurs  to  the  west  of  the 
deposit,  which  was  not  improbably  originally  a  limestone  band 
in  the  schists,  was  subsequently  metamorphosed  to  garnet  and 
wollastonite  and  mineralised  by  solutions  carrying  gold,  copper, 
and  platinum.  Selected  samples  of  bornite  assayed  from  |  ounce 
to  75  ounces  gold  per  ton. 


NEW    GUINEA. 

British  New  Guinea. — The  great  mountain  chain  of  New  Guinea 
is  formed  by  Archsean  crystalline  schists  and  metamorphic  rocks, 
and  is  continued  from  the  mainland  south-east  through  the  islands 
of  the  D'Entrecasteaux  and  of  the  Louisiade  groups.  An  immense 
area,  extending  from  near  Port  Moresby  to  the  German  frontier 
(Lat.  8°  S.),  is  occupied  by  these  rocks.  Another  similar  area  occurs 
further  east  near  Mount  Suckling  (11,226  feet),  and  the  intervening 
Owen  Stanley  range  may  be  conjectured  to  be  also  of  Archaean 
schists.6  It  is  these  ancient  rocks  that  furnish  the  gold  of  New 
Guinea  either  in  veins  in  situ,  or  detrital  in  the  river  valleys.  Quartz 
veins  have  not  been  worked  on  the  mainland,  except  at  Gibara, 
near  Milne  Bay.  The  Gibara  veins  were  small  and  were  soon  aban- 
doned. More  or  less  successful  vein-mining  has,  however,  been, 
carried  on  since  1900  on  Woodlark  Island  (Murua),  180  miles  north- 
east of  Samarai,  which  is  now  the  principal  port  of  New  Guinea. 
Woodlark  is  an  upraised  island  with  coral  reefs  elevated  1 50  feet  above 
sea-level.  The  gold-bearing  formation  at  Kulamadau,  the  principal 
centre,  is  merely  an  impregnated  band  in  the  country,  14  feet  wide, 
and  defined  by  clay  walls.c  Both  clay  and  lode-formation  carry 
about  2  per  cent,  pyrites.  Irregular  pockets  or  bunches  of  calcite 
occur  throughout  the  formation,   and  contain  veinlets  of  galena 


"  Trans.  Inst.  Min.  Met.,  XIII,  1904,  p.  551. 

1  Maitland,  West  Aust.  Nat.  Hist,  Soc.,  1905,  p.  23. 

c  Pinder,  Trans.  Inst,  Min.  Met,,  X,  1902,  p.  87. 


BRITISH    NEW    GUINEA. 


301 


that  are  invariably  rich  in  gold.  The  principal  company  operating 
on  Woodlark  Island  had  in  1906  reached  a  depth  of  435  feet.  The 
return  from  the  veins  of  the  island  for  that  year  was  10,527  ounces, 
valued  at  £33,549.  The  average  yield  of  the  quartz  crushed  was 
17  dwts.  21  grains  gold  per  ton  ore."  Other  mining  centres  on 
the  island  are  at  Karavkum  and  Busai.  At  the  latter  place  alluvial 
washing  has  been  carried  on  in  deposits  containing  fossil  bones. 
The  yield  of  alluvial  gold  from  Woodlark  Island  for  1906  was  1,608 
ounces.  Mining  operations  on  Sudest  (Tagula)  and  St.  Aignan 
(Misima),  islands  of  the  Louisiade  group,  are  confined  to  gravels. 

On  the  mainland  of  British  New  Guinea  all  the  active  goldfields, 
Milne  Bay,  Keveri,  Yodda,  and  Gira,  are  placer  fields.  The  Milne 
Bay  field  is  in  the  extreme  south-east  of  the  mainland,  while  the 
Yodda  and  Gira  fields,  the  most  important,  are  on  the  Kumusi, 
Mambare,  and  Gira  rivers,  in  the  north-east  portion  of  British 
territory.  In  the  early  years  of  prospecting  in  New  Guinea,  from 
1889  to  1898,  very  rich  pockets  were  discovered  on  these  rivers. 
The  Mambare  is  believed  to  be  adapted  in  places  for  dredging,  but 
no  attempt  has  as  yet  been  made  in  that  direction.  The  prospector 
in  New  Guinea  has  many  difficulties  with  which  to  contend.  The 
climate  is  extremely  malarious,  provisions  are  extraordinarily  dear, 
while  the  jungle  is  dense  and  the  natives  are  dangerous.  Hence 
New  Guinea  has  never  experienced  the  "  rush  "  that  its  earlier- 
worked  rich  deposits  would  have  engendered  elsewhere.  The 
estimated  yield  of  the  mainland  goldfields  for  1906  was  12,000  to 
13,000  ounces  gold,  the  Yodda  and  Gira  fields  each  producing 
about  6,000  ounces. 

Official  returns  from  1888,  when  mining  was  commenced,  to 
1907  inclusive,  give  the  amount  of  gold  exported  as  some  258,622 
ounces,  worth  £935,831.  These  figures  by  no  means  comprise 
the  total  amount  produced,  For  example,  while  the  estimated 
yield  for  1906  was  24,227  ounces,  only. 14,633  ounces  were  entered 
for  export  in  that  year.  The  returns  for  the  last  three  years  available 
are  : — b 


Year. 

Ounces. 

Value,  Sterling. 

1904-5 
1905-6 
1906-7 

22,729 

24,227 
16,103 

£82,736 
87,869 
58,886 

a  Commonwealth  Reports,  1907,  British  New  Guinea,  p.  70. 
h  Murray,  Aust.  Min.  Stand.,  1907,  Ap.  1,  8,  pp.  331,  358. 


302 


EAST   INDIAN    ARCHIPELAGO. 


The  total  yield  to  1907  of  the  various  fields  since  the  commence- 
ment of  placer  mining  in  New  Guinea  is  estimated  as  below  : — 


Field. 

Crude  Ounces. 

Value,  Sterling. 

Louisiadc     

Murua  ( Woodlark  Id. ) 

Grira      

Milne  Bay 

Yodda 

Keveri 

19,147 

110,512 

51,122 

13,231 

(10,940 
: 1,6 70 

£68,376 
386,791 
191,707 

46,310 
228,525 

13,763 

Total 

258,622 

£935,471 

German  New  Guinea  (Kaiser  Wilhelm's  Land).— Gold  is 
found  in  this  colony  mainly  in  the  extreme  south-east,  adjoining 
British  territory.  The  Waria,  Wiwo,  Morope,  Pajawa,  and 
Majaina,  in  fact,  all  the  large  streams  along  the  coast  from 
the  British  boundary  to  Cape  Longuerue,  carry  a  little  gold. 
The  Waria  and  the  Wiwo  are  the  richest,  but  their  head- waters  and 
most  valuable  portions  are  in  British  New  Guinea.  Gold  also  occurs 
in  the  sands  of  the  Ramu,  the  largest  river  in  Kaiser  Wilhelm's 
Land/*  Veins  are  as  yet  unknown,  but  they  probably  occur  in 
the  "  diorite  '  of  the  higher  mountains,  since  gold  in  trifling 
quantities  is  found  scattered  over  the  slopes  of  these  ranges. 

NEW    CALEDONIA. 

Numerous  occurrences  of  gold  in  small  quantities  have  been 
reported  from  New  Caledonia.  Nearly  all  these  are  along  the 
Diahot  Valley  in  the  extreme  north-western  portion  of  the  island, 
but  one,  that  at  Mont  d'Or,  lies  a  short  distance  north  of  Noumea, 
the  principal  port.^ 

In  the  neighbourhood  of  the  Diahot  river  are  the  only  gold- 
quartz  veins  yet  worked.  The  oldest  of  these  is  the  Fernhill,  near 
Manghine.  This  vein  was  discovered  by  Australian  prospectors  in 
1870,  flourished  for  three  years,  and  has  since  been  spasmodically 
worked.  Its  output  for  the  first  three  years  was  4,134  2  ounces 
(128-576  kg.),  and  from  1876  to  1878  was  2,712-9  ounces 
(84-373  kg.),  worth  £11,200.°  The  vein  was  very  irregular  in  value 
and  in  extent,  yielding  as  high  as  5  ounces  per  ton.  The  early 
workings  exhausted  the  oxidised  zone,  which  persisted  to  a  depth  of 
90  feet,  and  which  was  succeeded  by  highly  pyritous,  lower-grade,  ore. 

a  Schmeisser,  Zeit.  fiir  prakt.  Geol.r  XIV,  1906,  p.  79. 

"  Pelatan,  "  Les  Richesses  Minerales  des  Colonies  francaises,"  Paris.  1902,  p.  4. 

c  Glasser,  Ann.  des  Mines,  Serie  lOme,  IV,  1904,  p.  507. 


NEW    CALEDONIA.  303 

The  Fernhill  ore-bodies  lie  near  the  contact  of  the  dark  schists 
of  the  left  bank  of  the  Diahot  with  the  mica-schists  that  are  more 
or  less  confined  to  the  right  bank.  The  dark  schists  are  somewhat 
slaty  and  are  seamed  with  veinlets  of  milky  quartz.  The  mica-schists 
are  of  an  ordinary  type  with  a  white  sericitic  mica.  The  strike  of 
the  foliation  of  the  schists  (N.  35°  E.)  is  that  of  the  contact  and 
of  the  ore-body.  The  last  appears  to  consist  of  a  zone,  from  3  to  4 
feet  wide,  of  hyaline  quartz  grains.  Gold  is  also  obtained  from 
silicified  bands  in  the  schist,  these  being  as  a  rule  highly  pyritous. 

Gold-quartz  veins  have  also  been  worked  in  the  mica-schists 
of  the  Tiari  mountains,  immediately  to  the  north  of  the  Diahot 
streams.  Here  are  situated  the  Rose  and  the  Berthe  veins.  The 
former  was  discovered  in  1890,  and  its  line  of  vein-country  extends 
eastward  continuously  for  some  6  or  7  miles.  Along  this  line  the 
band  is  more  or  less  auriferous,  possessing  veins  and  shoots  in  which 
a  limited  quantity  of  quartz  has  yielded  1  to  If  ounces  (30  to  50 
grammes)  gold  per  ton.  The  mica-schists  of  this  region  are  sericitic, 
and  contain  as  accessory  minerals,  pyrite,  almandine  garnet,  rutile, 
and  abundant  glaucophane.  Other  deposits  in  situ  are  in  the  dark 
schist  of  Pouembout,  the  melaphyre  of  Tongoue,  and  the  ophite 
(diabase  ?)  of  the  Queyras  mine  near  La  Foa. 

Alluvial  gold  is  nowhere  abundant.  The  richest  deposit  appears 
to  be  near  Galarino,  on  the  coast  at  the  foot  of  the  northern  slope  of 
the  Tiari  range.  It  is  an  extensive  deposit,  but  is  of  exceedingly 
low  grade.  It  appears  rather  to  be  the  result  of  surface  decompo- 
sition than  a  true  alluvial  deposit.  As  a  rule  its  gold  is  fine, 
but  a  nugget  of  25-7  dwts.  (40  grammes)  has  been  obtained. 
The  sands  of  the  Diahot  contain  a  little  gold  with  occasional 
grains  of  platinum.  Other  occurrences  are  in  the  Nakety  river  and 
in  the  Grosses  Gouttes  circle.  In  the  latter  case  the  gold  appears 
to  be  associated  with  granite  massives. 

On  the  whole,  the  auriferous  deposits  of  New  Caledonia  appear 
to  offer  little  encouragement  for  the  investment  of  capital,  or 
even  for  further  prospecting. 


FIJI. 

Gold  in  water-worn  quartz  has  from  time  to  time  been  obtained 
from  the  upper  reaches  of  the  Rewa  river,  north  of  Suva,  on  the 
island  of  Viti  Levu.  Such  gold  may  have  been  derived  either  from 
the  basement  Palaeozoic  metamorphic  schists  or  from  the  widely- 
spread  intrusive  Cainozoic  andesites.  In  the  latter  case  the  occur- 
rence would    resemble  those  of   the  Hauraki    Peninsula  of    New 


304  POLYNESIA. 

Zealand.  Specimens  seen  by  the  writer  were  thought  to  indicate  an 
andesitic  origin.  No  gold-quartz  veins  have  yet  been  discovered  on 
the  island.  Fiji  being,  however,  a  portion  of  that  ancient  continent 
of  which  New  Caledonia,  the  Solomon  Islands,  and  New  Guinea 
are  all  fragments,*  its  basement  metamorphic  rocks  may  well  be 
expected  to  yield  similar  veins. 


"  Woolnough,  Proc.  Linn.  Soc.  N.S.W.,  XXVII,  1903,  p.  457. 


305 


AUSTRALASIA. 


NEW    ZEALAND. 

Prompted,  by  the  discoveries  of  rich  gold  in  Victoria  and  New 
South  Wales  in  1851,  vigorous  search  for  similar  deposits  was  made 
in  New  Zealand.  In  the  following  year,  1852,  gold-dust  and  gold 
enclosed  in  quartz  was  found  in  the  Kapanga  Creek  at  Coromandel 
Harbour,  about  40  miles  from  Auckland  in  the  North  Island.  Owing, 
however,  to  the  fact  that  the  alluvial  deposits  were  small  and  of  little- 
value,  and  also  to  the  increasing  hostility  of  the  natives,  this  field  was 
abandoned  after  having  yielded  some  £1,200  gold.  The  next  gold- 
find  in  New  Zealand  took  place  in  1857,  in  the  Collingwood  district 
in  the  Nelson  province  of  the  South  Island  ;  the  next  and  the  first 
of  real  importance  as  affecting  the  history  of  the  Dominion,  was 
that,  in  1861,  of  the  rich  placers  of  Gabriel's  Gully,  Otago.  The 
news  of  these  finds,  supplemented  by  extraordinary  reports  of  the 
richness  of  the  placer  deposits  of  the  West  Coast  of  the  South 
Island,  precipitated  a  series  of  ''  rushes  '  from  the  New  South 
Wales  and  Victorian  alluvial  fields,  already  past  their  zenith- 
With  the  advent  of  the  Australian  diggers,  the  valley-gravel& 
of  Otago,  Southland,  and  the  then  hardly  accessible  West  Coast 
district,  were  thoroughly  prospected,  and  placers  of  great  value,, 
especially  along  the  beaches  of  the  Molyneux  (Clutha)  and 
Kawarau  rivers  in  Otago,  were  discovered.  No  gold-quartz  veins 
worthy  of  more  than  passing  attention  were  known  until  the 
purchase  from  the  Maoris  in  1867  of  the  Thames  goldfield,  some 
50  miles  from  Auckland.  Here  were  discovered  near  the  surface 
some  of  the  rich  bonanzas  that  are  characteristic  of  the  northern 
and  central  portions  of  the  Hauraki  Peninsula.  For  the  next 
20  years  gold-mining  in  New  Zealand  underwent  many  vicissitudes, 
and  it  was  not  until  1893  that  the  development  of  the  now  famous 
Waihi  mine  and  the  opening  up  of  similar  large  bodies  of  low-grade 
quartz  at  Waitekauri  and  Karangahake  in  the  southern  portion  of 
the  Hauraki  andesitic  area,  combined  with  the  steady  progress 
of  the  dredging  industry  in  Otago  and  Westland  in  the  South 
Island,  placed  the  industry  on  a  sure  industrial  foundation. 

New  Zealand  therefore  possesses  three  well-defined  and  well- 
separated    auriferous   areas  :     {a)  the    Hauraki    goldfield    on    the 


306 


AUSTRALASIA. 


peninsula  of  that  name  on  the  north-east  coast  of  the  North  Island  ; 
this  area  contains  valuable  vein  deposits,  but  no  placers  ;  (b)  the 
West  Coast  area,  lying  along  the  western  slopes  of  the  Alps  of  the 
South  Island  in  the  provinces  of  Nelson  and  Westland  ;  in  this 
area  the  vein  and  alluvial  occurrences  are  of  equal  importance  ; 
and  (c)  the  Otago  area,  in  which  the  auriferous  alluvial  placer  gravels 
are  of  importance  and  the  few  known  gold-quartz  veins  of  little 
economic  value. 

The  following  table  shows  the  annual    export  of  gold  from 
New  Zealand  since  1857  :  — 


Year. 

Gold. 

Year. 

Gold. 

Ounces. 

£ 

Ounces. 

£ 

1857 

10,437 

40,422 

1884 

229,946 

921,797 

1858 

13,534 

52,464 

1885 

237,371 

948,615 

1859 

7,336 

28,427 

1886 

227,079 

903,569 

1860 

4,538 

17,585 

1887 

203,869 

811,100 

1861 

194,031 

751,873 

1888 

201,219 

801,066 

1862 

410,862 

1,591,389 

1889 

203,211 

808,549 

1863 

628,450 

2,431,723 

1890 

193,193 

773,438 

1864 

480,171 

1,856,837 

1891 

251,90(5 

1,007,488 

1865 

574,574 

2,226,474 

1892 

238,079 

954,744 

1866 

735,376 

2,844,517 

189:; 

226,811 

913,138 

1867 

686,905 

2,698,862 

1894 

221,615 

887,839 

1868 

637,474 

2,504,326 

1895 

293,491 

1,162,164 

1869 

614,281 

2,362,995 

1896 

263,694 

1,041,428 

1870 

544,880 

2,157,585 

1897 

251,645 

980,204 

1871 

730,029 

2,787,520 

1898 

280,175 

1,080,691 

1872 

445,370 

1,731,261 

1899 

389,558 

1,513,17:; 

1873 

505,337 

1,987,425 

1900 

373,616 

1,439,602 

1874 

376,388 

1,505,331 

1901 

455,561 

1,753,783 

1875 

:i^5,322 

1,407,770 

1902 

508,045 

1,951,433 

1876 

322,016 

1,284,328 

1903 

533,314 

2,037,831 

1877 

371,685 

1,496,080 

1904 

520,320 

1,987,501 

1878 

:;  lo,486 

1,240,079 

1905 

520,486 

2,093,936 

1879 

287,464 

1,148,108 

1906 

563,843 

2,270,904 

1880 

305,248 

1,227,252 

1907 

508,208 

2,027,490 

1881 

270,561 
251,204 

1,080,790 
1,002,720 

1882 

1883 

248,374 

993,352 

18,218,678 

£71,528,978 

In  addition  to  the  foregoing,  silver  to  the  value  of  more  than  a 
million  sterling  has  been  recovered,  mainly  from  the  gold-quartz 
veins  of  the  Hauraki  Peninsula,,  and  this  sum  is  therefore  to  be 
placed  to  the  credit  of  gold-mining. 

Hauraki.— The  Hauraki  Peninsula  is  the  most  northerly 
gold-mining  area  in  New  Zealand.  Its  auriferous  rocks  extend  for  a 
total  length  of  120  miles  north  and  south,  with  an  average  breadth 
of  some  15  miles.  They  are  continued  to  the  north  in  the  Great 
Barrier  Island,  which  is  geologically  a  continuation  of  the  peninsula. 


NEW    ZEALAND.  307 

The  oldest  rocks  of  the  area  are  Palaeozoic  and  Lower  Mesozoic 
unfossiliferous  slates  and  sandstones.  With  these  are  associated 
more  or  less  contemporaneous  volcanic  rocks  that  are  pre-Jurassic 
in  age.  Apparently  resting  on  these,  and  only  recently  distinguished 
as  a  result  of  the  work  of  the  Geological  Survey  of  New  Zealand," 
are  conglomerates,  grits,  grauwackes,  and  argillites.  Fragmentary 
fossils  from  the  conglomerates  have  been  identified  as  Inoceramus 
hastii  and  Belemnites  sp.,b  thus  indicating  an  Upper  Jurassic 
horizon.  The  pre-Jurassic  and  Jurassic  rocks  are  known  only  in 
the  north  and  north-west  of  the  peninsula,  with  the  single  exception 
of  a  minute  exposure  a  few  miles  north  of  Thames  on  the  south- 
west coast  of  the  peninsula.  In  the  northern  portion  of  the 
peninsula  is  a  small  area  of  Cretaceo-Tertiary  sediments,  which, 
from  stratigraphical  evidence,  appear  to  be  older  than  the  andesitic 
eruptive  rocks  that  cover  the  greater  portion  of  the  peninsula. 
The  latter  may  be  broadly  divided  as  hereunder  :  — 

(a)  Upper  Eocene  (?)  :  "Auriferous  Series"  of  andesitic  and 
dacitic  flows,   breccias,   and  tuffs  ;    all  much  propylitised. 

(b)  Miocene  :  Beeson's  Island  group  of  andesites  and  dacite- 
breccias  and  tuffs. 

(c)  Pliocene  :  Acid  igneous  rocks,  developed  to  the  east  and 
south  of  the  peninsula,  mainly  rhyolite,  pumiceous  agglomerate, 
pitchstone,   &c. 

The  main  "  Auriferous  Series  "  covers  a  great  portion  of  the 
peninsula  and  contains  nearly  all  the  important  gold  veins.  The 
rocks  of  the  series  have  recently  been  extensively  studied  so  far 
as  their  general  propylitisation  would  admit/  They  are  andesites, 
showing  both  hyalopilitic  and  pilotaxitic  (micropoecillitic)  structure. 
The  chief  varieties  occurring  are  pyroxene-andesite,  hypersthene- 
andesite,  hornblende-andesite,  and  hornblende-pyroxene-andesite. 
With  the  andesites  are  associated  dacites,  that  carry  hypersthene, 
or  hornblende,  or  pyroxene,  or  a  combination  of  any  two  or  of  all 
three,  as  ferro-magnesian  silicates.  Both  andesites  and  dacites 
have  been  extensively  propylitised  in  many  parts  of  the  area  to  a 
white,  yellow,  or  bluish-green  soft  rock  with  which  the  auriferous 
veins,  as  in  Transylvania,  are  always  associated.  The  processes  of 
propylitisation  are  indeed  here  precisely  the  same  as  those  described 
for  certain  andesitic  goldfields  of  Western  North  America  and  for 
the  dacites  and  andesites  of  Transylvania.  The  ultimate  result  is 
a  soft,  not  greatly  coherent  rock,  made  up  mainly  of  quartz,  kaolin, 
chlorite,  pyrite,  &c. 

a  Fraser,  Bull,  IV,  N.Z.  Geol.  Surv.,  1907,  p.  Jl'. 

b  Tliomas,  ibid.,  p.  49. 

c  Sollas,  "  Rocks  of  Cape  Colville  Peninsula,"  I,  1905,  Wellington. 


308  AUSTRALASIA. 

The  Beeson's  Island  group  is  nowhere  known  to  be  auriferous  ; 
and  microscopic  analysis  shows  its  rocks  to  be  andesites  and 
dacites  of  types  not  greatly  differing  from  those  of  the  auriferous 
series.  The  members  of  the  group  are  nevertheless  easily  distin- 
guished in  the  field,  the  younger  group  presenting  a  distinctly 
trachytic  facies,  while  the  ferro-magnesian  silicates  are  also  on  the 
whole  more  porphyritic. 

The  younger  acid  rocks  (rhyolite,  &c.)  of  Pliocene  age,  cover 
a  large  portion  of  the  peninsula,  especially  in  the  east  and  south. 
They  do  not,  as  a  rule,  carry  auriferous  deposits,  but  gold-quartz 
veins  have  been  found  in  them.  It  is  believed  that  the  Broken 
Hills  mine,  Tairua,  lies  within  these  rocks."  The  volcanic  activity 
of  Pliocene  times  has  apparently  persisted  to  the  present  day, 
since  the  recent  tuffs  and  lavas  of  the  Hot  Lakes  region  to  the  south 
show  no  vital  differentiation  either  in  time  or  in  type. 

Speaking  generally,  the  gold-quartz  veins  of  the  northern 
portion  of  the  area  are  irregular  both  in  extent  and  in  tenor.  They 
have,  however,  especially  when  they  form  a  network  of  interlacing 
stringers,  proved  at  times  exceedingly  rich.  In  the  southern  areas 
of  Karangahake  and  Waihi,  the  veins,  on  the  other  hand,  are 
large  and  well-defined,  but  are  of  comparatively  low  grade. 

Dealing  in  detail  with  the  fields  of  the  Hauraki  Peninsula, 
space  can  be  given  in  this  place  for  a  consideration  only  of  the 
chief  areas,  viz.,  Coromandel,  Thames,  Waihi,  and  Karangahake. 

The  Coromandel  field h  lies  some  40  miles  due  east  of  Auckland, 
across  the  Hauraki  Gulf.  The  basement  rocks  of  the  area  are  the 
pre-Jurassic  rocks  to  which  allusion  has  already  been  made.  These 
include  ancient  volcanic  felsitic  tuffs  as  well  as  ordinary  detrital 
sediments.  The  andesites  and  dacites  of  the  '"Auriferous  Series"  here, 
as  elsewhere  in  the  peninsula,  are  remarkably  deficient  in  amygda- 
loids,  pointing  to  lavas  cooling  with  sufficient  slowness  to  admit 
of  the  complete  escape  of  imprisoned  steam. 

The  reefs  of  the  Coromandel  district  are  exceedingly  erratic 
in  course,  dip,  and  tenor.  The  richest  occur  in  zones  or  belts  of 
propylitised  rock.  Three  principal  reef -channels  or  lode-zones 
occur  on  the  Coromandel  field :  the  Hauraki,  Kapanga,  and 
Tokatea.  There  is  a  possibility  that  they  are  merely  separated 
portions  of  a  single  zone  of  solfataric  action. 

The  gold  of  Coromandel  is  of  higher  grade  than  is  usual  on  the 
peninsula,  being  some  750  to  800  fine.  In  the  Hauraki  and  Kapanga 
areas  crystallized  gold  is  absent,  but  in  the  Tokatea  area,  where 

a  McKay  and  Sollas,  "  Rocks  of  Cape  Colville  Peninsula,"  I,  pp.  61,  267. 

6Maclaren.  Ann.  Rep.  Mines  Dept.,  New  Zealand,  1900;    Fraser,    Bull.  N.Z.  GeoL 
Surv.,  No.  4.  1907. 


NEW    ZEALAND.  309 

the  andesites  are  only  a  few  hundred  feet  above  the  pre-Jurassic 
rocks,  it  is  the  rule  to  find  free  gold  in  vughs  and  particularly  in 
calcite  veins.  One  remarkable  form  from  the  Rainbow  Reef, 
Tokatea,  made  up  of  five  plates  of  crystallized  gold,  simulated  to  a 
remarkable  extent  a  butterfly."  The  form  has  been  described 
elsewhere  in  this  volume.  In  most  cases  in  which  calcite 
and  quartz  occur  together  in  veins  deposition  appears  to  have 
been  contemporaneous.  A  remarkable  association  of  native  gold 
with  native  arsenic  has  been  met  with  in  the  Tokatea  area.  The 
arsenic  forms  hollow  geodes  with  concentric  shells  that  are  easily 
broken  off  in  succession.  In  the  hollow  interior  are  numerous 
interlacing  dendritic  threads  of  gold,  which  may  in  the  aggregate 
weigh  several  ounces.  The  geodes  often  weigh  several  pounds  and 
may  be  6  to  8  inches  in  diameter.  Gold  is  not  found  in  the  division 
planes  separating  the  concentric  spheres  of  growth.  In  the  rich 
pay-shoots  the  gold  is  generally  finely  distributed  throughout  the 
quartz  matrix.  The  associates  of  the  gold  are  native  arsenic, 
stibnite,  pyrite,  chalcopyrite,  and  arsenopyrite.  The  veins 
are  small  and  erratic,  the  richest  of  recent  years  being  Legge's 
Reef  in  the  Hauraki  area.  From  this  and  immediately  adjacent 
reefs  a  little  more  than  £400,000  gold  has  been  extracted, 
of  which  £222,583  has  been  distributed  in  dividends.  The  veins 
were  small,  but  much  of  the  quartz  carried  2  to  6  ounces  of  gold  per 
pound  of  stone.  The  total  gold  yield  of  the  Coromandel  area  is 
not  certainly  known,  but  to  the  end  of  1906  may  be  estimated  at 
£1,743,790.6 

The  Thames  goldfield  lies  near  the  head  of  the  Hauraki  Gulf. 
Its  productive  area  is  only  a  little  over  a  square  mile  in  extent. 
The  country  of  the  veins  is  entirely  andesitic,  but  the  underlying 
sedimentary  pre-Jurassic  rocks  outcrop  as  a  small  exposure  some 
two  miles  north  of  the  auriferous  field.  The  principal  veins  run  north- 
north-east  and  south-south-west,  occurring  in  parallel  zones  of 
decomposed  rock  separated  by  bands,  locally  termed  '  bars,"  of 
less  decomposed  rock.  The  field  is  traversed  by  exceptionally 
well-defined  comparatively  recent  faults,  of  which  the  Moanataiari 
is  the  chief.  This  fault  is  apparently  one  of  the  elements  in  the 
formation  of  the  graben  area  of  the  Hauraki  Gulf  and  its  former 
prolongation,  now  the  swampy  plains  of  the  Thames  Valley.  The 
trace  of  the  Moanataiari  Fault  may  be  followed  on  the  surface  for 
several  miles,  the  downthrow,  as  indicated  by  the  difference  in  level, 
being  some  350  feet.c    The  fault  hades  south-west  at  453.      Much 

"Maclaren,  Trans.  N.Z.  Inst.,  XXXI,  1899,  p.  492,  where    the    crystal   faces  were 
figured  in  error.     See  Fig.  46. 
"  Fraser,  loc.  cit.  sup.,  p.  18. 
c  Park,  "Geology  and  Veins,  &c,  of  the  Hauraki  Peninsula,"  Auckland,  1897,  p.  62. 


310 


AUSTRALASIA. 


NEW    ZEALAND.  31  1 

of  the  productive  area  of  the  field  is  on  the  seaward  side  of  it. 
Movements  have  taken  place  along  it  at  comparatively  recent  dates, 
since  the  slickensided  footwall  is  still  well-preserved,  and  the  streams 
from  the  footwall  side,  on  crossing  the  fault,  suddenly  emerge  from 
the  narrow  upper  valley  to  the  broader  portion  brought  into  juxta- 
position by  downthrow. 

The  major  vein-systems  of  the  field  follow  a  general  north- 
easterly course.  The  systems  are  made  up,  as  a  rule,  of  one  or  two 
main  lodes  with  numerous  irregular  branching  and  cross  veins. 
The  veins  are  celebrated  for  their  bonanzas.  Of  these  the  Shotover 
and  Caledonia  bonanzas  were  the  richest,  the  latter  producing 
from  a  limited  area  9  tons  of  gold  in  15  months.  The  yield  of  the 
Thames  field  has  generally  depended  for  any  given  year  on  a  single 
mine.  Sometimes  one  and  sometimes  another  has  been  in  bonanza. 
The  steadiest  producer  has  always  been  the  Waiotahi  mine,  which 
has  consistently  paid  dividends  on  a  small  capital  since  1873. 
From  1905  to  1908  this  mine  has  been  in  bonanza,  as  shown  in  the 
following  table  :  — 

£  s.  d. 

Yield  to  December,  1904        193.079  6  8 

1905 73,918  9  1 

1906        223,678  4  3 

1907        149,820  12  0 


Total  £640.496  12     0 

The  occurrence  of  "  specimen  stone  "  (containing  from  1  to  6 
ounces  gold  per  pound  of  quartz)  is  characteristic  both  of  this  field 
and  of  the  Coromandel  field  to  the  north.  The  associates  of  the 
gold  are  pyrite,  chalcopyrite,.  galena,  stibnite,  blende,  pyrargyrite, 
&c.  The  Norfolk  vein  in  the  north  of  the  field  has  a  gangue  of 
quartz  which  is  coloured  pink  with  rhodonite,  thus  resembling 
certain  veins  near  the  Gold  King  mine  in  the  San  Juan 
mountains,  Colorado,  also  in  andesites.*a 

The  main  reefs  are  accompanied  by  numerous  stringers  both 
in  the  hanging-  and  foot-walls.  These  are  often  mined  as  a  single 
body.  Their  intersections  within  the  network  are  often  rich,  and 
it  was,  in  fact,  such  a  stockwork  that  formed  the  Shotover 
and  Caledonian  bonanzas.  The  gold  is  very  irregularly  distributed, 
occurring  in  ill-defined  shoots  and  pockets.  The  bullion  is  about 
650  fine,  but  varies  considerably  from  various  parts  of  the 
field,  and  even  from  different  parts  of  the  same  reef.  The  rich 
pay-shoots  of  the  Thames  area  have  hitherto  been  confined  to  the 

"  Purington,  in  lift. 


312  AUSTRALASIA. 

upper  zones  above  a  depth  of  500  feet  ;  none  have  been  continuous 
below  that  level,  though  independent  but  lower-grade  shoots  are 
known  at  depths  of  640  feet.  The  continuation  of  the  veins  and 
shoots  in  depth  is  a  matter  that  is  indissolubly  connected  with  the 
range  of  propylitisation  of  the  andesite  ;  it  is  also  dependent,  though 
in  a  lesser  degree,  on  the  depth  at  which  the  floor  of  pre-Jurassic 
basement  rock  may  be  encountered.  Veins  do  occur  in  the  latter 
rocks,  as  at  Kuaotunu,  on  the  north-eastern  side  of  the  peninsula, 
and  do  also  continue  from  the  overlying  andesite  into  the  pre- 
Jurassic  rocks  below,  as  at  the  Royal  Oak  mine,  Coromandel,  but 
in  neither  case  have  they  proved  of  great  value  in  the  older  rocks. 
Considerable  analogy  in  the  latter  case  is  shown  by  the  veins  of  the 
Vulkoj-Korabia  area  in  Transylvania,  where  the  rich  lodes  of  the 
overlying  dacites  are,  in  the  basement  rocks,  either  poor  or  are 
entirely  barren. 

The  Karangahake  district  is,  next  to  Waihi,  the  most  productive 
of  the  areas  of  the  southern  portion  of  the  Hauraki  Peninsula. 
It  is  situated  at  the  mouth  of  the  great  gorge  cut  through  andesites 
by  the  Ohinemuri  river  at  a  point  some  8  miles  west  of  Waihi. 
The  veins  at  Karangahake  lie  in  andesitic  flows  and  breccias.  Two 
mines  of  some  importance,  the  Talisman  and  the  Crown,  are 
working  on  reefs  of  the  same  names.  The  reef  of  the  former  is  from 
3  to  4  feet  in  width,  with  ill-defined  foot-  and  hanging- walls.  The 
quartz  shows  the  peculiar  lamellar  or  platy  structure  due  to  the 
removal  of  calcite  from  a  quartz-calcite  mixture  in  which  the 
quartz  has  been  moulded  on  lamellar  and  rhombohedral  calcite. 
The  pay-ore  occurs  in  well-marked  shoots,  and  averages  in  value 
from  £2  to  £3  per  ton  ;  the  proportion  of  gold  to  silver  by  weight 
is  1  :  20.  A  small  branch  vein  contains  rich  gold  with  stibnite, 
calcite,  and  siderite.  Cobalt  is  also  present,  but  has  been  determined 
only  by  analysis. 

The  Talisman  Consolidated  Mines  had  produced,  to  the  end 
of  1907,  bullion  to  the  value  of  £783,334.  The  output  of  the  Crown 
Mines  had  been  a  little  less,  viz.,  £718,767.  The  present  annual 
value  of  the  yield  of  the  former  is  about  £150,000,  and  of  the  latter 
about  £50,000. 

Some  little  distance  to  the  east  of  Karangahake  is  an  interesting 
occurrence  of  cinnabar.  The  ore  is  contained  in  a  flat-lying  lode 
or  band  of  hard  chalcedonic  quartz,  through  which  the  cinnabar 
is  disseminated.  It  is  not  yet  known  whether  the  deposit  will 
prove  of  economic  value. 

The  Waihi  district  lying  at  the  base  of  the  Hauraki  Peninsula, 
contains  one  of  the  most  productive  of  the  world's  gold  mines. 
It  is  situated  on  a  broad,  somewhat  barren,  bracken-clad  plain, 
representing  the  bottom  of  an  ancient    lake  basin  that  now  lies 


NEW    ZEALAND. 


313 


nearly  300  feet  above  sea-level  and  is  almost  surrounded  by  hills. 
The  characteristic  topographic  features  of  the  Waihi  area  are  the 
Martha,  Union,  Amaranth,  and  Black  hills,  rising  as  islands 
of  andesite  above  the  general  level  of  the  rhyolite  plain.  In  former 
days  the  great  outcrop  of  the  Martha  lode  was  a  conspicuous  feature 
in  the  vicinity  of  the  mines.  It  had  indeed  been  known  to  pros- 
pectors since  1878,  and  towards  1890  had  been  worked,  but 
unprofitably,  by  the  pan-amalgamation  process.  Its  true  develop- 
ment, however,  dates  from  the  introduction  of  the  cyanide  process— 


Fig.  98.     Geological  Sketch  Map  of  th"e  Waihi  Mine  (Fraser). 
1.  Altered  Dacites  (vein-bearing).      2.  Younger  Andesites  and  Dacites.      3.  Rhyolites. 

a  method  of  metallurgical  treatment  that  has  proved  exceptionally 
well-suited  for  the  recovery  of  the  exceedingly  fine  gold  of  the 
Waihi  lodes.  The  Waihi  mine  itself  is  situated  at  the  end  of  a  long, 
low  spur,  that  juts  out  southward  into  the  plain  from  the  andesitic 
ranges  in  the  north.  This  narrow  peninsula  is  wrapped  round  on 
three  sides  by  younger  rhyolites.  Towards  the  south-east  and 
some  600  to  700  yards  from  the  Martha  Hill,  an  island  of  andesitic 
rock  appears  above  the  rhyolite  plain,  and  contains,  among  others, 
the  Union  and  Silverton  reefs. 

In  the  Waihi  area  there  is  no  sign  of  the  pre-Jurassic  basement 
rocks  that  are  seen  to  underlie  Tertiary  volcanics  at  Coromandel 


314 


AUSTRALASIA. 


and  at  Thames.  So  far  as  may  be  made  out  at  present  the 
country  of  the  Waihi  veins  is  the  highly  propylitised  and  weathered 
andesite  of  the  "Auriferous  Series."  It  has,  nevertheless,  been 
apparently  originally  somewhat  more  acid  in  character  than  the 
rocks  of  the  already-mentioned  goldfields  lying  further  to  the  north. 
Rocks  from  the  neighbourhood  of  the  Waihi  lodes  have  been 
described  by  Sollas  as  quartz-hypersthene-andesite  and  (apparently 
from  much  the  same  locality  and  horizon)  pyroxene-soda-rhyolite, 
the  latter  being  distinguished  by  containing  a  soda-bearing  ortho- 
clase,  so  far  as  its  nature  can  be  judged  from  the  somewhat  meagre 
microscopical  and  chemical  evidence  it  furnishes.      The  question 


Fig.  99.    Vertical  Cross-section  through  Martha  Hill  {Fraser). 

A.  Surface  soils,  &c.     B.  Flow  rhyolite.     C.  Brccciated  flow  rhyolite.     I).  Old  Land  Surface. 

E.  Younger  andesites  and  dacites.  F.  Old  Land  Surface  with  silicified  and  carbonized  wood. 

G.  Altered  vein-bearing  dacites. 

being  one  of  considerable  interest,  the  following  description  n  of  the 
acid  rocks  may  be  quoted,  the  rock  described  coming  from  the 
No.  3  level,  Waihi  mine  :  — 

Hornblende-pyroxene-rhyolite. — "A  light  greenish-grey  rock,  with 
obvious  quartz  and  pyrites.  The  matrix  is  granular,  polarising, 
much  altered,  crowded  with  felspar  laths  in  stream  lines,  which  are 
obvious  with  ordinary  light  but  scarcely  visible  with  cross-nicols, 
most  of  them  not  at  all.  Irregular  quartz  grains  ;  Phenocrysts  : 
Orthoclase.  Numerous  large  crystals  beginning  to  pass  into  mus- 
covite.  Some  fimbriate  at  the  margin,  showing  continued  growth 
after  extension.      Pyrites  crystals  included  in  some. 

"  Hornblende  represented  by  numerous  resorption  pseudomorphs. 

"  Pyroxene  represented  by  pseudomorphs  in  chlorite,  small,  and 
not  very  numerous. 

"Quartz  :  A  few  corroded  grains  and  bi-pyramids. 

"Ilmenite  :  A  few  plates  in  leucoxene. 

"  Pyrites  :  Numerous  scattered  cr\^stals.:5 


°  Sollas,  loc.  cit.  sup.,  II,  p.  67. 


NEW    ZEALAND. 


315 


In  view  of  the  occurrence  of  orthoclase  (valencianite)  in  the 
lodes  of  Waihi,  and  of  the  exceedingly  altered  state  of  the  country, 
it  is  conceivable  that  the  orthoclase  found  in  the  above  rock  may 
be  valencianite  due  to  secondary  action ;  indeed,  considerable 
indication  of  such  a  growth  is  outlined  in  the  foregoing 
petrological  description.  It  is  therefore  probable  that  the 
highly-decomposed  rocks  of  the  Waihi  area  do  not  represent 
original  rhyolites,  but  a  local  succession  of  andesites,  dacites, 
and  even  more  acid  rocks  that  have  been  so  thoroughly 
altered  by  solfataric  solutions  that  many  of  their  original 
characters  have  disappeared.  The  possibly  rhyolitic  rocks  in  this 
complex  must  in  any  case  be  sharply  distinguished  from  the 
younger  rhyolites  that  at  a  much  later  (Pliocene)  stage  filled  the 
valleys  and  depressions  caused  by   sub-aerial  erosion  in  the  rocks 


Ne8  800 


Fig.  100.     Cross -section,  Waihi  Mine,  showing  "  Blind  "  Lodes  (excepting  Edward  vein,  parallel 

to  line  of  section)  {Fraser). 


of  the  "Auriferous  Series."  Since  the  younger  rocks  contain  no 
quartz  lodes  it  may  be  inferred  that  their  deposition  took  place 
subsequently  to  the  propylitisation  of  the  andesites  and  dacites. 

The  vein  system  of  Waihi  is  somewhat  complex,  as  will  appear 
from  the  accompanying  sketch-map.  The  quartz  reefs  are  large  and 
numerous  (sixteen  are  known),  but  are  all  connected.  The  principal 
are  the  Martha,  Welcome,  Empire,  Edward,  and  Royal.  The  Martha 
is  the  main  lode  of  the  mine,  striking  north-north-east  and  south - 
south-west  and  underlying  south-east  at  very  steep  angles.  At 
the  surface  its  width  varied  from  20  to  60  feet,  with  an  outcrop  of 
over  300  yards.  At  a  depth  of  900  feet  its  range  in  width  is  from 
70  to  110  feet.  As  already  mentioned,  the  outcrop  showed  as  a 
steep  bluff,  the  white  quartz  of  which  was  visible,  especially  in  the 


316  AUSTRALASIA. 

rays  of  the  setting  sun,  from  many  miles  across  the  plain.  The 
Martha  lode  traverses  the  Waihi  mine  property  from  one  boundary 
to  the  other.  The  Welcome  lode  ranges  in  width  from  50  to  100  feet, 
the  Empire  lode  from  25  to  30  feet,  the  Royal  about  14  feet,  and  the 
most  recently  discovered,  the  Edward,  from  50  to  70  feet.  The 
last  at  the  maximum  width  has  shown  assays  of  £10  per  ton.  The 
filling  of  the  lodes  is  calcific  quartz.  The  walls  are  not  at  all  well- 
defined,  and  the  general  appearance  of  the  lodes  indicates  successive 
opening  along  fissures  near  the  surface  and  successive  fillings  with 
quartz  along  the  openings  thus  formed,  together  with  a  very 
considerable  amount  of  metasomatic  replacement  of  the  fissure- 
walls.  The  lodes  are  enclosed  in  a  thoroughly  decomposed  country 
highly  impregnated  with  pyrite.  The  ore  is  a  hard  grey  to  white 
quartz  with  calcite  ;  it  is  occasionally  laminated,  the  laminations 
being  often  rendered  apparent  by  banded  inclusions  of  silver 
sulphides.  Its  average  value  is  £2.  14s.  per  short  ton.  In  the  upper 
levels  the  development  of  lamellar  quartz  from  the  vein-mixture 
of  quartz  and  calcite  is  notable.  In  this  case  the  calcite  is  dissolved 
out  by  acid  waters,  the  resulting  cavities  being  found  partly  filled 
by  manganese  oxides/'  The  sulphides  amount  to  about  3  per  cent, 
of  the  ore,  and  are  mainly  pyrite  and  blende.  The  sulphide  ore  of 
the  lower  levels  now  furnishes  the  greater  part  of  the  gold,  though 
oxidised  ore  has  been  found  below  800  feet.  Selenium  occurs  in 
the  ore,  but  has  been  met  with  only  in  the  bullion  and  has  not  been 
identified  as  a  mineral.  With  this  occurrence  an  interesting  analogy 
is  afforded  by  the  Radjang-Lebong  mine,  Sumatra,  also  in  andesitic 
rock.  Nickel  and  cobalt  have  been  detected  in  close  analyses,  and 
are  apparently  associated  with  the  manganese  oxides  that  are  found 
filling  the  cavities  in  the  lamellar  quartz  of  the  oxidation  zone. 
The  gold  is  very  finely  divided  and  is  rarely  visible.  The  pro- 
portion of  silver  to  gold  in  the  ore  is  about  7:1.  The  rich  ore 
of  Waihi  is  a  characteristically  banded  quartz.  The  sulphide  ore 
contains  both  more  gold  and  more  silver  than  the  ore  of  the  oxidised 
zone.  There  is,  indeed,  considerable  evidence  for  the  assumption 
of  an  impoverishment  rather  than  an  enrichment  of  the  Waihi 
lode-outcrops.  The  uppermost  sulphide  zone  at  the  base  of  the 
zone  of  oxidation  was  very  rich,  averaging  from  1  to  2  ounces  gold 
and  30  to  60  ounces  silver  per  ton,  while  exceedingly  rich  portions 
assayed  25  ounces  gold  and  1,000  ounces  silver  per  ton. 
Morgan6  therefore  maintains  that  there  has  been  a  definite 
zone   of  secondary  sulphide-enrichment.      The  greater  part  of  the 

a  Lindgren,    Eng.  Min.  Jour.     Feb.  2,   1905;     Bell  and  Fraser,  Can.  Min.  Jour., 
Aug.,  1908. 

b  Eng.  Min.  Jour..  May  4,  1905,  p.  861. 


NEW    ZEALAND. 


317 


gold    is   contained    in   pyrite,    and   little    is   found  in  the    rarely 
occurring   galena  and  blende. 

The  Martha  lode  has  been  proved  for  a  length  of  over  3,400 
feet  in  the  Waihi  Company's  mine,  and  for  a  depth  of  1,000  feet. 
Many  of  the  other  lodes  above  enumerated  have  been  discovered 
only  by  underground  prospecting,  since  the  majority,  large  as  they 
are,  are  so-called  "blind"  lodes  that  do  not,  as  shown  in  Fig.  100, 
reach  the  surface,  and  therefore  show  no  outcrops. 

The  Waihi  Grand  Junction  mine  is  situated  on  the  strike  of 
the  Martha  lode  to  the  east.  The  lode  is  there  much  smaller.  This 
mine  has  produced  during  1906  and  1907  bullion  to  the  value  of 
£89,626.  Its  section  of  the  lode  is  hidden  beneath  a  bed  of  rhyolite 
that  has  filled  the  ancient  valley  on  the  slopes  of  which  the  Martha 
lode  outcropped. 

At  Waihi  Beach,  6  miles  from  Waihi,  a  secondary  auriferous 
deposition  has  taken  place  in  spherulitic  rhyolites  of  Pliocene  age. 
The  presence  of  such  secondary  gold-deposits  is  not  surprising, 
since  hot  springs  are  still  sporadic  along  the  eastern  coast  of  the 
peninsula. 

The  total  output  of  the  Waihi  mine  from  1890  to  the  end  of 
1907  is  shown  in  the  following  table  :  — 


1890  ... 

...     ... 

£13,628 

1900  ...  112,012  tons  ...  £317,902 

1891  ... 



36,458 

1901  ...  159,325  , 

...  461,205 

1892  ... 

18,297  tc 

>ns  ...   46,219 

1902  ...  179,485  , 

...  521,574 

1893  ... 

19,805 

64,345 

1903  ...  231,323  , 

...  658,393 

1894  ... 

24,364 

83,023 

1904  ...  259,978  , 

...  683,882 

1895  ... 

33,670 

...  120,335 

1905  ...   298,531  , 

...  728,521 

1896  ... 

34,410 

...  135,156 

1906  ...  328,866  , 

...  837,927 

1897  ... 

40,764 

...  144,041 

1907  ...  356,974  , 

...  878,486 

1898  ... 

1899  ... 

77  Q99 

...  256,494 
...  302,525 

1  I  ,  O £i*J 

102,381 

Total 

£6,290,120 

To  March,  1908,  there  had  been  paid  in  dividends  £2,926,215. 
The  total  costs  of  treatment  were  in  1907  about  £1  per  ton.  Among 
the  other  mining  camps  of  the  Hauraki  Peninsula  is  the  Great 
Barrier  Island,  where  the  reefs  are  large  but  of  low  grade,  varying 
in  tenor  from  30s.  to  £3  per  ton.  The  yield  during  1907  of  the 
Great  Barrier  mines  was  only  some  £650.  At  Kuaotunu  on  the 
north-eastern  coast  the  veins  carry  finely  divided  gold  and  lie  in 
the  pre-Jurassic  basement  sedimentary  rocks.  The  yield  has 
never  been  extensive.  In  the  southern  area  besides  the  camps  of 
Waihi  and  Karangahake  already  mentioned,  are  the  important  veins 
of  Komata  and  Waitekauri.  At  the  former  place  low-grade  veins 
are  on  the  whole  being  successively  worked.  The  Komata  Reefs 
mine  from  its  opening  in  1900  produced  to  the  end  of  1907  bullion 
of  the  value  of  £273,176.     At  Waitekauri  a  large  reef  was  worked 


3 1  8  AUSTRALASIA. 

and  jnelded  considerable  quantities  of  gold,  but  with  a  change  in 
the  reef  in  depth  from  the  lamellar  quartz  similar  to  that 
characteristic  of  the  Waihi  and  Karangahake  mines  to  the 
original  mixture  in  depth  of  quartz  and  calcite,  the  mine  became 
too  poor  to  work,  and  was  finally  abandoned.  The  Broken  Hills 
mines  at  Tairua,  where  gold-quartz  veins  are  being  profitably 
Avorked  at  or  near  the  junction  of  rhyolite  and  andesite,  has 
produced,  from  1900  to  1907  inclusive,  bullion  to  the  value  of 
£81,390. 

West  Coast.  — In  the  middle  auriferous  area  of  New  Zealand 
stretching  along  the  western  slopes  of  the  mountain  ranges  of 
the  South  Island,  both  gold-quartz  veins  and  placer  deposits 
derived  from  them  are  numerous.  In  the  Nelson  and  Marlborough 
provinces  the  veins  are  in  micaceous  schists  of  indefinite  age.  The 
only  mine  of  importance  in  this  area  is  situated  at  Taitapu,  near 
Nelson.  The  placer  deposits  of  these  two  northern  provinces 
include  modern  river  gravels,  high-level  gravels,  and  ancient  Tertiary 
folded  sediments." 

In  Westland,  the  centre  of  quartz-mining  is  Reefton,  Avhere 
veins  occur  in  Palaeozoic  (Carboniferous  ?)  strata.  The  country  is 
grey  talcose  clayey  shales  and  sandstones.  The  veins  strike  with 
the  country  and  several  parallel-bedded  veins  are  occasionally 
worked  as  one  reef.  The  quartz-bodies  consist  of  extremely  irregular 
bunches  and  masses  branching  in  all  directions  into  the  country. 
They  are  nevertheless  aggregated  along  certain  lines,  longitudinal 
connection  being  made  by  narrow  fissures  that  sometimes  contain 
quartz,  but  more  often  "  pug."  The  narrow  fissures  occur  in  the 
harder  parts  of  the  rock,  the  quartz  ore-bodies  as  a  rule  in  the  softer 
country.  Deposition  of  gold  takes  place  generally  on  the  slaty 
selvages  of  the  veins  and  also  in  quartz  containing  angular  fragments 
of  the  argillite  or  grauwacke  of  the  country.  This  type  of  brecciated 
ore-filling  is  locally  known  as  "  magpie  stone."  The  veins  vary  in 
thickness  between  4  and  40  feet  ;  in  depth  they  pinch  to  mere 
threads,  but  often  recover  their  former  width  with  deeper  sinking. 
The  average  tenor  of  the  quartz  raised  is  10  to  14  dwts.  gold.  The 
gold  is  of  high  quality,  reaching  a  value  of  £4  per  ounce.  Don^ 
has  shown  that  the  hard  rock  at  Reefton  contains  little  or  no  pyrite 
and  is  not  auriferous,  while  the  softer  rock  adjacent  to  the  quartz- 
veins  was  both  pyritous  and  auriferous.  Nevertheless,  pyrite  taken 
from  slates  at  points  distant  from  the  auriferous  lodes  carried  no 

a  McKay,  "  Gold  Deposits  of  New  Zealand,"  Wellington,  1903. 
b  Trans.  Amer.  Inst.  M.E.,  XXVII..  1898,  p.  584. 


Plate   IX. 


Open-cut,  Martha  Lode,  Waihi,  New  Zealand. 


The  Humphrey's  Gully  Beds,  Westland,   New  Zealand. 
Auriferous  Gravels  overlain  by  Morainic  Debris. 


NEW    ZEALAND. 


319 


gold.     The  output  of  the  principal  mines  of  the  Reefton  district  is 
shown  in  the  following  table  :  — 


Mine. 

Average 

Value  of  Ore 

per  Ton. 

Value 

Proiluceil  in 

1906. 

Total 

Dividends 

P.iid  to 

End  of  1906 

Consolidated  Goldtields  of  New  Zealand 

Progress  Mines  of  New  Zealand 

Keep-it-Dark  Company 

£      s.       (1. 

1    17     5 
1     14     5 
1    16  10 

£ 
36,307 
91,200 
18,887 

137,606 
261,250 
154,666 

The  subscribed  capital  of  the  last-named  company  was  no 
more  than  £6,208.  It  has  been  in  successful  operation  for  33  years  ; 
its  present  total  working  costs  are  only  10s.  9d.  per  ton.  In  the 
Reefton  district  from  the  31st  March,  1880,  to  the  31st  December, 
1906,  a  total  quantity  of  1,285,771  tons  of  ore  were  crushed  for  a 
yield  of  687,555  ounces  gold  worth  £2,715,838. 

The  Lyell  goldfield,  25  miles  further  north,  shows  similar 
geological  features.  Elsewhere  in  Westland  quartz-mining  is  carried 
on,  as  at  Boatman's  and  at  Blackwater,  in  mica-schist. 

The  majority  of  the  short  rapid  rivers  of  Westland  carry 
auriferous  gravels.  These  are  attacked  by  hydraulicing  and  by 
dredging.  In  both  respects  they  have  yielded  successful  mines. 
Auriferous  black  sands,  consisting  largely  of  magnetite  and  ilmenite, 
occur  in  many  places  along  the  west  coast  of  South  Island  of  New 
Zealand,  and  are  worked,  especially  after  storms,  by  individual 
miners.  The  gold  of  the  black  sand  is  exceedingly  fine  and 
presents  considerable  difficulty  in  treatment. 

Otago. — Numerous  gold-quartz  veins  occur  in  ancient  crystal- 
line quartz-schists  and  phyllites  in  the  central  and  nortii-western 
portions  of  the  provinces  of  Otago.  The  prevailing  rock  throughout 
central  Otago  is  mica-schist,  which  is  generally  foliated  with  quartz- 
laminse  and  is  interbedded  at  times  with  thick  bands  of  chlorite- 
schist.  Quartz-schists  are  also  common,  while  occasional  bands 
of  actinolite-schist  may  be  met  with.  In  most  places  the  schists 
are  sharply  contorted  and  show  a  silky  lustre  on  corrugated  surfaces. 
Towards  the  upper  part  of  the  series  the  schists  become  insensibly 
less  and  less  altered  and  pass  into  argillaceous,  arenaceous,  and 
micaceous  rocks.  So  far  as  is  known,  igneous  dykes  are  entirely 
absent  from  the  schist  areas,  although  granites,  syenites,  and  basic 
dykes  form  the  great  mountain  complex  further  to  the  west  between 
the  southern  lakes  and  the  fjord  regions.  The  whole  appearance 
of  the  schists,  together  with  their  composition,  undoubtedly  warrants 
the  assumption  that  the  original  unaltered  rocks  from  which  the 


320  AUSTRALASIA. 

schists  have  been  metamorphosed    were  sediments  and  were  not 
igneous  rocks. 

The  quartz-veins  in  the  Central  Otago  schists  are  often  auriferous 
but  are  poor  and  of  low  grade.  In  few  places  have  they  been  found 
sufficiently  rich  to  work.  The  most  valuable  are  those  of 
Skippers,  Macetown,  and  Arrowtown,  all  lying  to  the  north  of  Lake 
Wakatipu  in  the  front  valleys  of  the  New  Zealand  Alpine  chain, 
which  here  reaches  a  height  of  some  10,000  feet.  Other  reefing 
areas  of  less  importance  are  Waipori  and  Nenthorn,  towards  the 
eastern  coast,  and  the  Preservation  Inlet  field  in  the  extreme 
south-west  corner  of  the  island. 

At  Macetown  the  Premier  forms  the  principal  lode  system. 
It  is  traceable  for  nearly  2,000  feet,  but  the  greater  part  of  it  is 
filled  with  "  mullock,"  or  broken  schist  country,  which  carries  small 
quartz  veins  and  contains  much  carbonaceous  matter.  Here, 
three  nearly  parallel  veins  are  met  by  a  cross  reef,  pay-shoots  being 
formed  at  the  intersections. 

At  Skippers,  which  is  separated  from  Macetown  by  a  ridge 
6,000  feet  high,  the  Phoenix  mine  has  been  most  productive.  The 
lodes  are  three  in  number  and  form  a  parallel  system  that  traverses 
a  well-defined  lode  channel.  As  on  many  other  fields  characterised 
by  parallel  veins,  the  pay-shoots  in  the  lodes  are  never  opposite 
one  another  either  vertically  or  horizontally.  At  the  Phcenix  mine, 
therefore,  a  pay-shoot  on  one  lode  denotes  two  barren  zones  imme- 
diately opposite.  Further,  the  lodes  of  Skippers  are  always  poor 
when  their  strike  is  south  of  west,  but  their  tenor  improves  when 
their  strike  turns  to  north  of  west.  Don's  researches a  have 
shown  for  this  region  that  the  quartz  folia  of  the  mica-schist  are 
not  auriferous  when  pyrites  is  absent,  and  further,  that  pyrites 
is  present  in  appreciable  quantity  only  when  the  quartz  laminse 
are  near  an  auriferous  lode. 

The  alluvial  deposits  of  Otago  are  of  considerable  value.  Of 
the  6,215,914  ounces  exported  from  the  province  from  1861  to 
1906,  a  very  great  proportion  came  from  the  placers.  Much  of  the 
placer  gold  was  won  by  the  individual  digger  working  along  the 
beaches  of  the  Molyneux  and  Kawarau  rivers  at  times  of  low  water, 
using  only  the  crudest  of  appliances — the  pan,  cradle,  and  long-torn. 
In  later  days  many  attempts  were  made  to  recover  by  machinery 
the  gold  inaccessible  to  the  ordinary  digger  from  the  deeper  waters 
of  these  swift-running  rivers.  It  was  indeed  these  attempts  that 
gave  rise  to  the  modern  dredging  methods  that  now  find  world- 
wide application.  The  early  dredges  were  dippers  worked  by  hand  ; 
these  after  a  time  were  succeeded  by  current-wheel  dredgers,  in  which 

"  Loc.  cit.,  p.  581. 


NEW    ZEALAND.  321 

the  motive  power  that  raised  the  gravel  from  the  river  bottom  was 
furnished  by  the  strength  of  the  current.  The  success  of  the  earlier 
steam  dredges  working  on  the  richer  bars  and  ridges  was  so  marked 
that  many  dredges  were  hurriedly  built  to  work  in  spots  from  whence 
there  was  little  hope  of  remuneration.  In  1900  the  dredging  boom 
was  at  its  height,  but  by  1907  only  35  dredges  remained  in  operation 
in  Otago,  and  eight  on  the  West  Coast.  In  1906  the  Otago  dredges 
produced  £415,117  gold,  and  those  of  the  West  Coast  £86,082. 

The  alluvial  placers  of  Otago  never  attained  the  importance  nor 
furnished  the  yield  per  cubic  yard  of  those  of  Victoria  or  of  California. 
Much  of  the  alluvial  drift  is  of  Lower  Miocene  age,  though  the  gravels 
on  which  most  dredges  are  now  operating  are  recent,  and  are  often 
merely  a  re- wash  of  the  Miocene  gravels.  No  large  nuggets  have 
been  found  in  the  New  Zealand  placers,  the  heaviest  on  record 
weighing  only  27  ounces.  The  source  of  the  alluvial  gold  is  the 
quartz  veins  and  the  quartz  laminae  of  the  mica-schists  and  quartz- 
schists."  These  rocks  are  easily  eroded  and  their  constituent 
minerals  are  quickly  separated  in  the  channels  of  the  rivers  in  which 
the  waters  flow  with  currents  of  6  to  even  7  knots  an  hour,  thus 
forming  ideal  natural  sluices.  The  rivers  have  a  fairly  even 
gradient,  and  are  subject  to  periodic  floods  arising  from  the 
melting  of  the  snows.  While  the  floods  are  not  sufficiently  strong 
to  scour  the  bottom  or  to  cut  fresh  channels  for  the  river,  the 
current  is  yet  adequate  to  roll  over  and  to  triturate  the  quartz 
pebbles  and  to  liberate  their  contained  gold.  The  lighter  mica  is 
readily  removed  by  the  river  currents,  even  when  flowing  at 
speeds  much   less  than  their  normal. 

Numerous  high-level  auriferous  gravels,  which  are  often 
well  cemented,  are  worked  by  hydraulicing.  Of  these  the  Blue 
Spur  deposits  near  Lawrence  are  typical.  They  lie  at  the  head  of  the 
Gabriel's  Gully,  where  the  first  payable  placer  gold  was  found  in 
1861.  The  deposit  is  a  great  mass  of  cemented  conglomerate  which 
has  been  preserved  by  having  been  faulted  down.6  Its  shape  is 
roughly  oval,  and  its  original  area  was  some  45  acres.  The  matrix 
contains  boulders  of  sizes  varying  up  to  2  feet  in  diameter.  The 
pebbles  are  cemented  by  a  light  greenish-blue  fine-grained  cement, 
from  which  the  designation  "  Blue  Spur  "  has  been  derived.  The 
stratigraphical  horizon  of  the  Blue  Spur  conglomerates  is  below 
the  Pliocene  coal  measures  (lignites)  of  Otago.  In  1906  the  Blue 
Spur  Company  treated  by  hydraulic  methods  over  200,000  cubic 
yards  of  cemented  gravel,  all  of  which  required  blasting,  for  an 
average  yield  of  6^d.  per  cubic  yard. 

a  Park,  Bull.  Geol.  Surv.  N.Z.,  No.  2,  1906. 

1  Rickard,  T.  A.,  Trans.  Amer.  Inst.  M.E.,  XXI,  1892,  p.  432. 

W 


322 


AUSTRALASIA. 


Loose  auriferous  gravels  are  worked  in  Otago  at  an  average 
cost  of  lfd.  per  cubic  yard  ;  in  the  West  Coast  district  the  costs 
are  slightly  higher,  reaching  2d.  per  cubic  yard. 

In  addition  to  the  foregoing  well-known  occurrences  small 
quantities  of  gold  have  been  reported  from  time  to  time  from  the 
central  active  volcanic  regions  of  the  North  Island.  In  this  connection 
certain  analyses  made  by  the  New  Zealand  Geological  Survey  may 
be  here  quoted  as  throwing  a  most  interesting  light  on  the  deposition 
of  gold."     Assays  of  the  sinter  of  the  Whakarewarewa  hot  springs 


P'igs.  101  aj<d  102.     Section  and  Plan  of  Bltjb  Spur  Gravels, 
Otago,  New  Zealand  (Riclcard). 

near  Rotorua,  yielded  silver  to  the  extent  of  4  ounces  18  dwts.,  and 
gold  to  the  extent  of  1  dwt.  4  grains  per  ton.  Again,  mud,  composed 
mainly  of  quartz,  amorphous  silica,  and  a  little  felspar,  from  the 
famous  Waimangu  geyser,  perhaps  the  greatest  known  within  the 
historical  period,  but  now  unfortunately  extinct,  gave  on  assay 
6  dwts.  1  grain  silver  and  5  grains  gold  per  ton. 

Gold  has  also  been  obtained  near  Cape  Terawhiti,  Wellington. 


a  Bell,  X.Z.   Mines   Kecord,  Jan.,  1908,  p.  242;    Maclaren.    Geol.  Mag.,  Dec.,  IU, 
1906,  p.  514. 


Plate  X. 


Junction    of   Clutha    and    Kawarau    Rivers,    Cromwell 


-4^^ 


The  Clutha,  below  Roxburgh. 
GOLD-DREDGING  RIVERS,  NEW  ZEALAND. 


NEW    ZEALAND.  323 

About  1862  some  42  ounces  of  alluvial  gold  were  obtained  here  ; 
unpayable  gold-quartz  veins  in  Triassic  slates  and  sandstones 
are  also  known." 


AUSTRALIA. 

The  auriferous  vein-deposits  of  Australia  clearly  fall  into  two 
distinct  divisions,  that  are  well  separated,  both  geologically  and 
geographically.  The  older  includes  the  goldfields  of  Archaean 
and  pre-Cambrian  age,  in  the  west  and  north-west.  These  are 
associated  with  the  basement  metamorphic  schists  of  the  continent. 
The  younger  division  lies  along  the  great  Eastern  Cordillera 
of  Australia,  and  stretches  northward  from  Tasmania  through 
Victoria,  New  South  Wales,  and  Queensland,  and  is  continued  by 
way  of  the  Torres  Strait  islands  into  the  highlands  of  central  and 
north-western  New  Guinea.  The  deposits  of  this  class  are  apparently 
initially  dependent  on  great  granodioritic  intrusions  that 
have  taken  place  along  the  axial  line  of  earth  folding. 
The  gold-quartz  veins  may  occur  either  in  the  igneous 
rock  itself  or  in  the  sedimentary  strata  overlying  or  adjacent. 
While  the  general  age  of  the  granitic  or  granodioritic 
intrusion  (petrologically  it  finds  its  closest  analogue  in  the 
granodiorites  of  the  Californian  Sierra  Nevada)  is  not  definitely 
fixed,  there  are  many  reasons  for  assigning  the  intrusion  to  the  later 
stages  of  the  Permo-Carboniferous.fo  All  adjacent  strata  of  greater 
age  may  therefore  carry  auriferous  veins.  The  general  habitus  of 
the  gold  deposits  in  the  north  is  the  granitoid  rock ;  while 
in  the  south  gold-quartz  veins  are  more  often  found  in  the 
sedimentary  rocks  through  which  the  granodioritic  rocks 
are  intrusive.  Important  exceptions  to  both  rules  occur  and 
are  of  especial  value  as  forming  evidences  of  a  general  genetic 
connection  between  the  gold  deposits  of  the  north  and  south 
respectively.  The  uplift  in  the  north  having  been  greater, 
or  possibly  the  overlying  beds  having  been  thinner,  denudation 
has  proceeded  to  relatively  greater  depths  there  than  in  the 
south,  where  the  auriferous  mineralisation,  while  not  so  obviously 
connected,  e.g.,  in  Bendigo,  Ballarat,  and  Beaconsfield  (Tasmania), 
with  igneous  intrusions  as  in  the  northern  fields  of  Queensland, 
is  nevertheless  to  be  referred  to  the  same  period  of  volcanic 
activity.  With  the  information  available  at  the  present 
time  there  appears  no  valid  reason  for  separating  those  goldfields 

a  McKay,  loc.  cit.  sup.,  p.  5. 

b  Andrews,  Proc.  Linn.  Soc.  KS.W..  Ser.  3,  VII,  1902,  p.  167. 


324 


AUSTRALASIA. 


that  are  apparently  dependent  on  basic  rocks  {e.g.,  augite- 
andesites,  as  at  Lucknow,  Gympie,  &c.)  from  the  general 
series,  since  the  more  basic  rocks  are  not  widespread,  and,  when 
considered  as  a  whole,  may  be  regarded  as  either  local  segregations 
from  the  acidic  magma  or,  more  probably,  as  the  normal 
basic  members  generally  sequent  on  acidic  eruptions.  It  has 
already  been  suggested  that  the  actual  auriferous  deposition  may 
possibly  have  been  a  function  of  the  extrusion  of  these  more 
basic  members.  The  remarkable  similarity  of  the  Eastern 
Australasian  chain  of  goldfields  to  those  of  the  Calif ornian  type, 
extending  along  the  Pacific  slope  from  Lower  California  to 
Northern  Alaska,  may  once  more  be  pointed  out.  It  is  perhaps 
more  than  a  coincidence  that  the  greatest  alluvial  deposits  of  the 
modern  world  should  have  been  derived  from  parent-veins  in  rocks 
so  similar.  In  Australia,  as  in  California,  auriferous  concentration 
has  proceeded  in  the  rivers  during  the  whole  of  Tertiary  time. 
In  each  country  many  of  the  older  placers  have  been  covered  by 
basaltic  flows. 

The  subjoined  table  shows  the  total  gold  yield,  to  1907 
inclusive,  of  Australia  since  the  year  1851,  when  the  placer 
deposits  of  New  South  Wales  were  first  known  :  — 


State. 

Gold. 
Fine  Ounces. 

Value,  Sterling. 

Victoria 

Western  Australia 

Queensland      

New  South  Wales 

Tasmania          

South  Australia         

65,792,063 
18,363,787 
15,603,481 
13,034,001 
1,535,017 
626,329 

£279,498,833 

78,004,406 

66,278,652 

55,364,882 

6,523,821 

2,757,562 

Commonwealth        

114,954,678 

£488,428,144 

QUEENSLAND. 

The  history  of  gold  in  Queensland  opens  with  the  ill-fated 
"rush"  to  Canoona  in  1858,  when  15,000  to  20,000  diggers  were 
left  starving  on  the  banks  of  the  Fitzroy  river,  near  the  site  of  the 
present  town  of  Rockhampton.  Disaster  was  averted  only  by  the 
prompt  action  of  the  Governments  of  New  South  Wales  and  Victoria 
in  sending  steamers  to  the  spot  to  take  away  the  unfortunate 
adventurers.  The  irony  of  fate  is  illustrated  by  the  facts  that 
Canoona  is  only  12  miles  from  Mount  Morgan,  one  of  the  greatest 
of  the  world's  gold  mines,  and  that  there  was,  moreover,  considerable 
alluvial  gold  in   the   neighbourhood   that   remained   undiscovered 


QUEENSLAND.  325 

by  the  early  diggers.  There  is  thus  considerable  analogy  between 
this  abortive  rush  and  another,  and  even  greater,  that  was  taking 
place  about  the  same  time  to  Pike's  Peak  in  Colorado,  beside  the 
then  unknown  Cripple  Creek  field,  destined  in  later  days  to  become 
so  widely  famed. 

In  1862,  alluvial  gold  was  found  near  Peak  Downs,  Clermont, 
and  this  field  remains  to  the  present  day  the  principal  placer  region 
of  Queensland.  The  first  reef  worked  in  Queensland  was  the  Hector 
on  the  Crocodile  goldfield,  near  Rockhampton.  The  date  of  its 
discovery  was  1865.  In  1867,  the  Gympie,  and  in  1868,  the 
Ravenswood  fields  were  opened  up.  The  present  leading  field, 
Charters  Towers,  remained  unknown  until  1872. 

Yorkc  Peninsula. — Horn  Island,  one  of  the  Prince  of  Wales 
group,  lies  in  Torres  Strait,  and  with  others  of  the  group  (Possession, 
Prince  of  Wales,  Hammond,  and  Thursday  islands),  carries  slightly 
auriferous  veins.  Gold  in  payable  quantities  was  first  found  in 
1894.  The  auriferous  veins  lie  in  a  decomposed  granite  made  up 
largely  of  felspar  and  quartz,  with  a  green  decomposition  product 
from  a  ferro-magnesian  silicate. a  The  islands  are  a  continuation 
of  Yorke  Peninsula,  and  the  granites  are  probably  therefore  akin 
to  those  of  the  Queensland  Cordillera  that  furnish  the  greater  part 
of  the  gold  yield  of  the  State.  The  zone  of  oxidation  in  the  veins 
extends  only  to  10  feet  in  depth.  Pyrite  and  galena  are  common. 
The  veins  are  rich  but  are  very  small,  and  contain  refractory  ore. 
On  Possession  Island,  a  few  miles  south-east  of  Horn  Island,  small 
networks  of  auriferous  veins  in  a  similar  porphyritic  granite  have 
been  mined.6     These  fields  are  intermittently  worked. 

The  Hamilton  and  Coen  veins  form  the  most  northerly  of  the 
Queensland  mainland  goldfields.  They  are  situated  on  the  western 
slope  of  the  central  chain  of  the  Cape  Yorke  Peninsula.  The  veins 
lie  along  a  broad  zone  developed  along  the  contact  line  of  metamor- 
phic  schists  and  quartzites  with  biotite-granites.  Eurite  dykes 
are  common,  and  the  characteristic  tonalite  (quartz-mica-diorite) 
of  Charters  Towers  is  also  found.0 

The  Philp  (Alice  River)  field,  discovered  in  1904,  lies  at  the 
head  of  the  Alice  river,  140  miles  due  west  of  Cooktown,in  a  granite 
of  the  normal  auriferous  type.  The  value  of  the  quartz  crushed  is 
about  an  ounce  fine  gold  per  ton.  At  Starcke  goldfield,  50  miles 
north-west  of  Cooktown,  alluvial  gold  has  been  worked  since  1890. 
It  is  derived  apparently  from  veins  in  quartzites.     These  veins  are 

a  Cameron,  Rep.  Geol.  Surv.  Queensland,  Xo.  180,  1902,  p.  18. 

"  Loc.  cit.,  p.  22. 

c  Ball,  Rep.  Geol.  Surv.  Queensland,  No.  163,  1901. 


326  AUSTRALASIA. 

notable  for  the  association  of  gold  in  shoots  with  stibnite.0  Some 
of  the  veins  on  the  Munburra  section  are  associated  with  porphyry 
dykes. 

The  Palmer  goldfield  was  discovered  in  1873  and  for  a  time 
produced  large  quantities  of  alluvial  gold.  By  the  end  of  1877  it 
had  yielded  819,697  fine  ounces  of  alluvial  gold  worth  £3,481,849, 
in  addition  to  which  huge  quantities  had  been  smuggled  out  of 
the  country  by  the  Chinese  who  had  flocked  to  these  alluvial 
fields.  Soon  after  the  discovery  of  the  placers  the  veins  were  opened 
up  and  many  thousands  of  tons  of  quartz  were  crushed  for  yields 
of  1 1  to  2  ounces  per  ton.  The  total  produce  of  the  Palmer  gold- 
field  has  been,  to  the  end  of  1907,  some  1,323,735  ounces  fine  gold 
worth  £5,622,866. 

The  country  of  the  Palmer  veins  is  sedimentary  rock,  viz., 
shales,  sandstone,  and  limestones,  probably  of  Carboniferous  or  of 
even  greater  age.  It  is  to  be  correlated  with  that  of  the  Hodgkin- 
son  field,  60  miles  to  the  south-east.  The  sedimentary  rocks  are 
traversed  by  dykes  of  dolerite  and  diorite.  Both  the  Hodgkinson 
and  the  Palmer  fields  lie  close  to  great  areas  of  the  Permo-Carboni- 
ferous  granitoid  masses. b 

The  Hodgkinson  field  is  situated  some  60  miles  west  of  Cairns. 
Of  late  years  its  gold  yield  has  been  surpassed  by  the  value  of  wolfram 
and  molybdenite  obtained.  Stratified  rocks  of  the  Gympie  (Carboni- 
ferous) series,  composed  of  nearly  vertical  shales,  sandstones, 
grits,  and  conglomerates,  are  traversed  by  two  great  barren  quartz 
"  buck  reefs,"  3  to  40  feet  in  width.  The  material  of  the  "  buck 
reefs  "  often  resembles  a  granular  quartzite,  but  it  may,  on  the 
other  hand,  be  finely  laminated  and  jasperoid.  The  buck  reefs 
occasionally  form  sheer  upstanding  walls  100  feet  high,  and  may  be 
traced  by  the  eye  across  country  for  many  miles.  Two  groups  of 
auriferous  veins  may  be  made  out,  the  first  striking  with,  but 
underlying  at  right  angles  to  the  strata  ;  the  second  cuts  across 
the  strata  and  underlies  always  to  the  east.  Free  gold  occurs  in 
laminated  quartz,  and  is  associated  with  variable  quantities  of 
galena  and  pyrites.  Near  Thornborough,  the  Southern  Cross  reef 
carries  3  ounces  gold  per  ton  in  a  matrix  of  quartz  and  scheelite. 
The  yield  of  the  Hodgkinson  field  to  the  end  of  1907  had  been 
227,703   fine   ounces  gold,   worth   approximately   £967,000. 

Croydon.— The  Croydon  field  is  situated  some  100  miles 
south-east  of  the  head  of  the  Gulf  of  Carpentaria.0     It  is,  with  the 

a  Cameron,  Rep.  Geol.  Surv.  Queensland,  No.  209,  1907,  p.  6. 

b  Jack,  "Geology  of  Queensland,"  Brisbane,  1892,  p.  122;   Id.,  Rep.  Geol.  Surv. 
Queensland,  No.  144,  1899. 

c  Rands,  Rep.  Geol.  Surv.  Queensland,  No.  118,  1896 ;  Dunstan,  loc.  cit.  No.  202, 
l!Mi.-, ;  Id.,  loc.  cit.,  No.  212,  1907. 


QUEENSLAND.  327 

exception  of  the  comparatively  unimportant  Cloncurry  goldfield, 
the  most  westerly  of  the  Queensland  goldfields,  which  are,  as 
has  already  been  stated,  almost  entirely  grouped  along  the  flanks 
of  the  eastern  coastal  range,  and  are  in  close  genetic  connection 
with  the  granitoid  core  of  that  uplift.  The  goldfield  was  proclaimed 
in  1886  and  has  since  been  famous  for  its  exceedingly  rich  shoots 
of  gold.  The  country  of  the  reefs  is  a  granitoid  rock,  and,  to  a  lesser 
extent,  an  allied  felsite.  The  former  rock,  owing  to  the  greater 
rapidity  with  which  it  has  weathered,  is  now  almost  completely 
concealed  beneath  thin  conglomerates  and  sandstones  of  the 
Desert  Sandstone  (Upper  Cretaceous)  Formation,  and  beneath 
laterites  and  detrital  rocks  of  comparatively  recent  age.  The 
felsites,  on  the  other  hand,  form  the  hilly  country  to  the  north-east 
of  Croydon.  There  is  no  evidence  available  as  to  the  age  of  the 
granites  and  felsites,  but  it  may  be  shown  from  petrological 
data  that  they  are  probably  to  be  grouped  with  the  Permo- 
Carboniferous  intrusions  of  the  Cordilleran  uplift.  The  granite  is 
greatly  altered  even  at  depths  of  1,300  feet  from  the  surface.  It  is 
made  up  of  a  pink  or  grey  felspar  with  clear  quartz  and  contains 
a  little  dark-greenish  product  arising  from  the  alteration  of  horn- 
blende or  mica.  In  most  specimens,  however,  the  ferro-magnesian 
silicate  is  in  very  small  quantities,  and  in  such  cases  the  rock  pre- 
sents a  decidedly  aplitic  appearance.  The  associated  minerals  are 
remarkable.  Graphite,  occurring  apparently  in  broad  zones  in  the 
granite,  is  abundant,  as  also  is  calcite,  siderite,  and  fluorspar. 
As  might  be  expected  from  the  influence  of  igneous 
intrusions  on  the  carbonaceous  Pernio- Carboniferous  rocks,  the 
Queensland  auriferous  veins  in  general  carry  a  good  deal  of 
graphite,  e.g.,  at  Hamilton,  Coen,  Croydon,  Cloncurry,  Gympie, 
Normanby,  Yorkey,  Stanthorpe,  &c.  In  some  places  indeed 
the  actual  transition  from  coal  to  graphite  under  the  influence 
of  the  igneous  intrusion  may  be  made  out,  as  at  Mount  Bopple 
and  Cape  Upstarts  Graphite  also  occurs  under  similar  conditions 
in  New  South  Wales.  The  granite  country  is  impregnated  to  a 
small  extent  with  pyrite,  chalcopyrite,  galena,  and  arsenopyrite. 
Both  coarse  and  fine-grained  granites  occur.  The  former  have 
generally  been  supposed  to  be  intrusive  into  the  latter, 
but  for  this  assumption  there  is  no  clear  evidence.  The 
felsites  are  as  a  rule  fine-grained  rocks,  but  occasionally 
contain  free  quartz  in  large  grains.  They  also  contain  graphite. 
They  are  possibly  somewhat  younger  than  the  granites  since  felsitic 
dykes  have  been  noted  in  the  latter,  and  since  the  granite  appears 
to  underlie  the  felsite.     A  chain  of  intrusive  basic  (dolerite)  dykes 

a  Dunstan,  Rep.  Geol.  Surv.  Queensland,  No.  203,  1906,  p.  12. 


328  AUSTRALASIA. 

occurs  along  the  zone  of  reefs,  but  has  no  connection  whatever  with 
ore-deposition,  since  the  intrusion  is  obviously  subsequent  to  vein- 
filline,"  and  indeed  cuts  the  veins.  Later  faults  are  abundant 
and  have  disturbed  the  reefs  greatly.  Veins  occur  both  in  the 
granites  and  in  the  felsites.  In  the  former  they  lie  in 
"  formations,"  or  zones  of  disturbed  and  altered  country 
characterised  by  the  presence  of  abundant  graphite.  The 
value  of  the  Croydon  bullion  is  very  low,  being  a  little  over  £2  per 
ounce.  The  reefs  in  the  felsites  are  of  comparative  unimportance. 
Their  bullion  is,  however,  of  much  higher  grade,  being  worth 
perhaps  £3.  4s.  per  ounce. 

The  principal  reefs  are  the  Golden  Gate,  True  Blue,  Highland 
Mary,  &c.  These  are  dispersed  along  a  narrow  zone  running  north- 
west and  south-east  for  more  than  four  miles.  The  pay-ore  occurs 
in  rich  well-defined  "  shoots."  The  gangue  is  quartz,  which 
is,  in  the  case  of  the  Golden  Gate  reef,  of  three  kinds, 
and  has  been  formed  at  two  distinct  periods.  These  varieties 
of  quartz  are  locally  called  "gold  stone,"  "poor  stone,"  and 
"  buck."  The  "  buck  "  is  barren  and  occasionally  carries  pyrite, 
while  the  "  poor  stone  "  also  has  pyrite  and  differs  from  the  "  gold 
stone  ':  only  in  the  absence  of  galena  and  gold,  the  galena  in 
rich  stone  being  invariably  finely  divided  and  always  accom- 
panying the    gold.     An  excess  of  galena  indicates  rich  gold-quartz. 

The  Golden  Gate  reef  is  very  flat,  dipping  east-north-east  at 
18°.  It  has  been  worked  to  a  depth  of  1,600  feet  (Golden  Gate 
Consols  Shaft). 

Since  its  discovery  in  1886  the  Croydon  field  has  yielded  to 
the  end  of  1907  a  total  weight  of  704,828  ounces  fine  gold. 

Ethcridgc— The  Etheridge  goldfield  is  situated  on  the  same 
granite  massif  as  the  Croydon  field,  but  is  about  100  miles  further 
east-south-east.  The  oldest  rocks  of  the  district  are  sharply  folded 
slates,  schists,  sandstones,  and  quart  zites.  These  are  intruded  by 
diorites  that  have  generally  been  forced  along  the  bedding  planes. 
The  folded  sedimentaries  are  intruded  over  large  areas  by  granitic 
dykes  and  stocks  that  in  some  cases  occur  in  so  great  an  abundance 
as  almost  to  obliterate  the  characters  of  the  original  sedimentaries  ; 
more  especially  is  this  the  case  when  the  granite  apophyses  occur 
in  well-bedded  rocks.  Euritic  dykes,  intrusive  into  the  granite,  are 
found  in  some  parts  of  the  field. b  Sedimentary  strata  were 
deposited  on  the  metamorphic  and  igneous  rocks  during  older  and 
younger  Cretaceous  times,  the  later  deposits  being  the  wide-spread 
Desert  Sandstone. 

°Dunstan,  ibid.,  1905,  p.  11. 

b  Cameron,  Rep.  Geol.  Surv.  Queensland,  No.  151,  1900,  p.  2. 


QUEENSLAND.  329 

The  reefs  of  the  Etheridge  lie  near  the  border  of  the  main 
granitic  mass,  partly  indeed  in  the  slates  and  schists  and  partly 
in  the  granite.  They  are  small  and  refractory,  but  are  of  high 
tenor,  carrying  large  quantities  of  pyrite  and  galena,  with 
occasional  blende  and  chalcopyrite.  In  general  the  highly 
pyritous  veins  have  been  richer  immediately  below  water-level  than 
in  the  oxidised  zone  above.  Those  veins  lying  within  the  sedimentary 
rocks  at  some  distance  from  the  granite  contain  but  little  sulphide 
mineral.  The  progress  of  the  field  has  been  greatly  hampered  by 
the  high  cost  of  transport  and  of  supplies,  and  even  more  by  the 
local  difficulties  of  ore-treatment  and  by  the  scarcity  of  water. 
The  principal  reefs  are  the  St.  George,  Cumberland,  Durham,  and 
Queenslander.  Owing  to  the  exceedingly  refractory  nature  of  the 
ore,  the  veins  being  often  solid  pyrite  and  galena  below  water-level, 
no  great  depth  has  been  reached  by  these  mines.  The  total  yield 
of  the  Etheridge  fields  to  the  end  of  1907  was  494,937  fine  ounces. 

Cloncurry.— The  Cloncurry  goldfield  in  the  north-east  of 
the  State  is  the  only  auriferous  area  not  situated  on  the  line  of  the 
eastern  Cordilleran  uplift.  It  is,  nevertheless,  in  the  neighbourhood 
of  a  small  granitic  outcrop.  The  veins  are  of  little  importance,  and 
lie  in  sandstones  and  shales.  They  are  highly  pyritous.  The 
oxidised  products  at  the  outcrops  of  the  copper  lodes  of  the  district 
occasionally  contain  free  gold.  Gold  has  also  been  found  here 
associated  with  native  bismuth."  A  considerable  amount  of 
alluvial  gold  associated  with  native  bismuth  was  formerly  obtained, 
one  such  nugget  weighing  28  pounds  troy. 

Charters  Towers.— The  Charters  Towers  goldfield  has  for 
many  years  been  the  leading  field  in  Queensland.  It  lies  about 
1,000  feet  above  sea-level  and  some  80  miles  from  its  coastal  port 
of  Townsville.  It  is  probably  the  most  productive  of  those 
of  the  world's  goldfields,  whose  veins  lie  entirely  in  acid  plutonic 
rocks,  its  yield  being  a  little  more  than  a  million  sterling  per  annum. 
Its  general  geological  features  are  nevertheless  much  less  known 
than  those  of  many  a  poorer  and  less  accessible  field.  This  ignorance 
arises  mainly  from  the  fact  that  a  close  geological  survey  of  the 
area  can  be  attempted  only  with  the  aid  of  the  microscope  in  the 
field  itself.  Charters  Towers  rocks  have  a  fairly  wide  range  in  the 
acidic  plutonic  group — from  a  granite  with  little  ferro-magnesian 
content  to  a  tonalite  (quartz-mica-diorite).  The  relations  of  these 
rocks  in  the  field  have  yet  to  be  worked  out  in  detail.  They  have, 
however,  been  indicated  in  an  excellent  map  based  on  macroscopic 
characters,   and  published   in    1898  by  Messrs.  Jack,  Rands,  and 

a  Jack,  "Geology  of  Queensland,"  Brisbane,  1892,  p.  21. 


330 


AUSTRALASIA. 


Maitland,  of  the  Queensland  Geological  Survey.  The  map  is, 
however,  unaccompanied  by  any  written  description,  and  so  loses 
much  of  its  value.  Some  little  space  will,  therefore,  be  given  in 
this  place  to  a  description  of  the  petrological  characters  of  these 
rocks,  from  specimens  collected  on  the  field.  The  grey  granites 
show  numerous  quartzes  crowded  with  fluid-inclusions.  Felspars 
are,  as  a  rule,  somewhat  kaolinized,  but  are  orthoclase,  microcline, 
and  some  twinned  plagioclase  felspar.  The  ferro-magnesian  silicate 
is  normally  a  grass-green  hornblende.  Epidote  and  apatite  are 
accessory  minerals.  The  tonalites,  on  the  other  hand,  contain  little 
interstitial  quartz  with   enclosures  of  hornblende,  magnetite,  and 


Fig.  103.     Geological  Sketch  Map  of  Charters  Towers  Goldfield  (Jack,  Rands,  and  Maitland)- 

1.  Slates,  quartzites,  and  limestones  of  undetermined  age.      2.  Granite  and  tonalite  with  coarse  porphyry. 

3.  Quartz-schists.     4.  Diorite  (basic).    5.  Serpentine  (?).    6.  Recent  superficial  deposits. 


zoisite.  Their  felspars  are  nearly  all  striped,  but  all  are 
much  saussuritized.  The  majority  show  idiomorphic  outlines, 
and  many  are  well  and  strongly  zoned  with  a  saussurite  core. 
So  far  as  it  may  be  made  out,  the  extinction  angle  of  the 
felspar  is  20°  to  25°,  and  hence  is  fairly  close  to  that  of 
andesine.  A  little  clear  orthoclase  occurs  moulded  on  the 
plagioclase.  Brown  and  green  ragged  boitite-mica  is  abundant, 
and  generally  contains  "  eyes  "  of  epidote.  Hornblende  occurs  in 
small  grains,  but  is  not  abundant.      Epidote  is  present  both  as 


QUEENSLAND. 


331 


a  rock-forming  mineral  and  in  the  saussurite  product.  Zoisite 
occurs  in  the  interstitial  quartz.  Chlorite,  obviously  resulting  from 
the  decomposition  of  the  hornblende,  is  present  in  some  quantity. 
The  rock  may,  therefore,  be  regarded  as  a  typical  tonalite.  The 
author  is  indebted  to  the  courtesy  of  Mr.  W.  A.  MacLeod,  of  Charters 
Towers,  for  the  following  partial  analysis  of  this  rock  : — a 


&  Fe.,0. 


Si<X 

ai2o:. 

Na.,0.. 

k.2o  .. 

CaO     . . 
MgO    .. 

Loss  on  ignition 


67-00 

21-80 

5-22 

1-86 

4-16 

•  53 

•  90 

101-47 


A  third  type  of  rock  represented  in  the  writer's  collection  is  a 
light-grey  rock  showing  very  little  ferro-magnesian  silicate.  Under 
the  microscope  the  ground  mass  of  the  rock  shows  as  a  fine-granular 
aggregate  of  quartz  and  clear  felspars.  The  section  contains 
numerous  rounded  but  almost  idiomorphic  quartzes.  Other 
phenocrysts  are  orthoclase  in  small  quantity  and  plagioclase  com- 
pletely saussuritized.  Epidote  is  very  abundant.  On  the  whole, 
the  rock  may  be  most  conveniently  described  as  a  quartz-porphyry. 
The  petrology  of  this  field  certainly  promises  to  throw  considerable 
light  on  the  problems  of  auriferous  deposition,  and  further  work 
on  it  is  greatly  to  be  desired. 

A  short  distance  to  the  north-east  and  also  to  the  north-west 
of  the  main  auriferous  area  the  granitoid  rocks,  as  at  Ravenswood, 
a  neighbouring  field  to  be  described  later,  are  associated  with 
highly  indurated  slates  and  quartzites  of  undetermined  age,  but 
through  which  the  granites  and  tonalites  appear  to  be  intrusive. 
The  auriferous  country  generally  is  intersected  by  numerous  dioritic 
dykes  that  are  apparently  older  than  the  vein  fissures,  for  the 
latter  fault  the  former.  Many  of  the  richest  deposits  were  in  former 
days  found  at  the  intersection  of  the  veins  with  the  dioritic  dykes, 
especially  when  brecciated  fragments  of  the  dyke  were  scattered 
through  the  veinstone.  This  type  of  enriched  matrix  appears  to 
have  furnished  the  largest  pay-shoot  yet  discovered  on  the  Charters 
Towers  field,  viz.,  one  that  passed  from  the  upper  levels  of  the 
Day  Dawn  and  Day  Dawn  Block  and  Wyndham  mines  into  the  lower 
levels  of  the  Mills  United  mine.^  The  country  included  within  the 
lode  under  these  circumstances  showed  values  equal  to  that  of 
the  true  vein-quartz. 


a  MacLeod,  in  lift. 

b  Paull,  Trans.  Aust.  Inst.  M.E.,  III,  1895,  p.  244. 


332  AUSTRALASIA. 

The  average  width  of  the  main  reefs  of  the  field— the  Brilliant 
and  the  Day  Dawn  —  may  be  taken  as  3  feet.  Its  gangue,  as  already 
stated,  is  quartz  and  decomposed  granitoid  country.  The  Brilliant 
section  of  the  reef  channel  has  been  the  most  productive.  It  was,  in 
1908,  being  worked  below  2,700  feet  (Brilliant  Extended  Company). 
It  has  generally  been  supposed  that  the  Brilliant  and  Day  Dawn 
sections  were  portions  of  a  single  continuous  lode,  but  it  is  now 
certain  that  the  Day  Dawn  is  a  separate  lode  and  lies  to  the  east 
of  the  Brilliant.  The  lode-channel  consists  rather  of  a  chain  of 
ore-bodies  than  a  continuous  vein.  The  ore-bodies  are  seldom 
more  than  6  feet  in  width.  The  richer  pay-shoots  carry  from  1  to 
2  ounces  per  ton,  but  the  average  value  of  the  ore  is  very  much  less, 
and  is  probably  below  15  dwts.  per  ton.  The  gangue  contains  about 
7  per  cent,  of  sulphides  (pyrite,  galena,  blende,  pyrrhotite,  and  a 
little  arsenical  pyrites).  Free  gold  is  rarely  seen  in  depth.  Higher 
values  in  the  sulphide  zone  are  generally  indicated  by  galena. 
The  oxidised  zone  reached  a  depth  of  between  200  and  300  feet. 

The  total  yield  of  the  Charters  Towers  district  (which,  besides 
Charters  Towers  itself,  includes  the  long-abandoned  Cape  River 
goldfield)  from  the  discovery  of  gold  to  the  end  of  1907  was 
5,647,938  ounces  fine  gold  worth  nearly  £25,000,000  sterling.  In 
recent  years,  and  indeed  until  the  rise  of  the  Kalgoorlie  field  in 
Western  Australia,  the  Charters  Towers  field  held  the  premier 
position   among   Australian   goldfields. 

Ravens  wood. — The  Ravenswood  gold-quartz  veins,  discovered 
in  1868,  furnished  the  first  of  the  important  goldfields  of  Queensland, 
yielding  both  rich  placer  gold  and  rich  vein-quartz  in  the  oxidised 
zone.  Their  yield  to  end  of  1907  has  been  693,206  fine  ounces  gold 
worth  nearly  £2,950,000.  The  auriferous  veins  are  contained  within 
basic  granitite  (biotite -granite)  and  hornblende-granite  containing 
subordinate  orthoclase.  With  them  are  associated  quartz-porpyhries, 
quartz-felsites,  and  granophyres.  Numerous  felsite  dykes  traverse 
the  granite.  These  granites  are  probably  younger  than  a  series 
of  grauwackes  and  slaty  shales  that  are  developed  in  the  neighbour- 
hood. The  veins  carry  a  quartz-filling,  and  the  gold,  below  the 
oxidised  zone  (here  70  feet  in  depth),  is  always  associated  with 
galena,  arsenopyrite,  chalcopyrite,  bismuthinite,  and  blende.  The 
reefs  are  small,  from  8  inches  to  2  feet  in  width,  but  are  of 
high  tenor.  The  ore  is  refractory.  On  all  the  reefs  in  this 
field  the  pyrites-zone  when  first  struck  in  sinking  was  much 
richer  than  the  "  brownstone  v  above,  indicating  therefore, 
a   general  secondary  downward   enrichment. a       The  Donnybrook 

a  Maclaren,    Hep.     Geol.  Surv.    Queens.,    No.    152,    1900 ;     Cameron,   ib.,  No.  183, 
1903. 


QUEENSLAND.  333 

veins,  a  few  miles  south-east  of  Ravenswood,  lie  in  the  metamor- 
phosed rocks  very  close  to  the  granite  boundary  and  dip  with 
the  strata.  These  veins  are  small  and  erratic,  and,  when  in  the 
metamorphosed  sedimentary  rocks,  contain,  as  on  the  Etheridge 
goldfield,  more  free-milling  gold  and  less  sulphide-ore  than  those 
in  the  adjacent  granite. 

Minor  Central  Fields. — Of  minor  importance  is  the 
Normanby  goldfield,  lying  40  miles  south  of  Bowen  in  soft  decom- 
posed granite,  that  in  places  passes  almost  to  a  hornblende  gneiss. 
According  to  Jacka  the  veins  are  in  a  porphyry-rock  made  up  of 
quartz,  a  little  black  mica,  and  tourmaline  crystals,well  impregnated 
with  pyrite.  Of  similar  character  is  the  rock  of  the  Eungella  gold 
occurrences,  lying  a  little  further  south.  The  reefs  of  the  Mount 
Nebo  goldfield  next  to  the  south  occur  partly  in  diorite  and  partly 
in  grey  and  black  shales  and  sandstones  of  the  Gympie  Series 
(Carboniferous).  The  igneous  rocks  appear  to  be  partly  inter- 
bedded  and  partly  intrusive. 

Mount  Morgan.— The  Mount  Morgan  has  been  one  of  the 
most  productive  of  modern  gold  mines.  It  is  an  isolated  mine 
lying  26  miles  south-west  of  Rockhampton  on  the  Fitzroy  river  and 
just  within  the  Tropic  of  Capricorn.  It  was  discovered  in  1886 
and  carried  extraordinarily  rich  outcrop-stone.  The  name  is 
somewhat  of  a  misnomer  since  the  so-called  mount  was  originally 
only  500  feet  above  stream-level  and  1,225  feet  above  sea-level. 

Granite  rock  is  extensively  developed  in  the  district,  the 
auriferous  area  lying  between  two  large  outcrops  of  the  charac- 
teristic granite  of  the  Australian  Cordillera.  Hornblende  is  the  pre- 
dominant mineral,  but  the  rock  varies  greatly  in  character,  often 
ranging  from  a  normal  granite  to  syenite,  and  even  to  an  aplitic 
rock  or  to  a  quartz-felspar-porphyry.  The  auriferous  deposits 
themselves  lie  within  Gympie  (Carboniferous)  rocks.  These  are 
quartzites,  conglomerates,  grauwackes,  shales,  slates,  serpentines, 
and  limestones.  All  are  more  or  less  altered  and  metamorphosed. 
No  traces  of  granite  fragments  are  found  in  these  sedimentary  beds 
and  the  assumption  therefore  is  that  the  age  of  the  granite  intrusion 
is  at  least  more  recent  than  Lower  Permo-Carboniferous.  The 
metamorphism  of  the  Permo-Carboniferous  beds  further  points 
to  the  same  conclusion.  Vertical  basic  dykes,  apparently  of 
dolerites,  are  intrusive  through  the  Gympie  Series  in  the  neighbour- 
hood of  the  ore-deposits.  These  are  older  than  the  "  Desert 
Sandstone  "  that  occurs  in  the  neighbourhood,  and  are  probably 
later  than  and  have  no  genetic  connection  with  the  ore-deposition. 

a  "Geology  of  Queensland,"  p.  30. 


334 


AUSTRALASIA. 


The  basic  dykes  are  generally  hole-crystalline,  with  plagioclase, 
augite,  and  olivine,  but  vary  widely  in  texture  and  character. 
Four  principal  dykes  occur  in  the  ore-body.  These  are  the  two 
parallel  doleritic  north  and  south  dykes,  each  about  20  feet  wide 
and  separated  by  a  distance  of  some  500  feet ;  the  north  and 
south  andesite  dyke,  about  18  feet  in  width;  and  the  east  and 
west  dolerite  dyke.  The  whole  of  the  copper-gold  ores  of  Mount 
Morgan  lie  to  the  west  of  the  andesite  dyke,  though  gold  values 
are   obtained  on  both  sides  of  it.     In  addition  to  the  foregoing 


Fig.  104.     Geological  Sketch  Map  of  the  Vicinity  of  Mount  Morgan  {Jack}. 

1.  Granite,  granodiorite,   and  syenite.      2.  Gympie  (Carboniferous)  quartzites,  slates,  schists    and 
limestones.     3.  Desert  sandstones  (Upper  Cretaceous). 


the  ore-body    is  intersected    by  numerous    small  dykes,   striking 
all    directions,    and     ranging    up    to     5    feet     in     thickness." 


in 


The  Desert  Sandstone  (Upper  Cretaceous)  shows  in  the  neighbour- 
hood only  as  the  remnants  of  a  former  wide-spread  tableland. 
Its  basement  beds  are  auriferous,6  with  gold  obviously  derived 
from   the   neighbouring  Mount   Morgan  lodes.      Thus    a    superior 


a  Wilson,  Queensland  Govt.  Min.  Jour.,  Sept.  15,  190S. 
b  Jack/Rep.  Geol.  Surv.  Queens.,  No.  132,  1898,  p.  20. 


QUEENSLAND. 


335 


limit  to  the  age  of  Mount  Morgan  auriferous  deposits  is  furnished. 
Mount  Morgan  is  by  far  the  most  productive  mine,  both  in  gold 
and  in  copper,  in  Queensland.  The  total  value  of  both  metals 
produced  in  1907  being  £1,000,124,  of  which  £619,208  was  due  to 
gold  and  £385,705  was  the  value  of  copper.  The  copper  ore  is 
obtained  from  the  750-foot  level,  but  occurs  for  some  500  feet 
above  that  level,  the  oxidised  zone  persisting  for  250  feet  below 
the  original  summit  of  the  hill. 

The  Mount  Morgan  field  has,  since  its  discovery  in  1886, 
produced  in  fine  ounces  (of  which  all  but  a  few  hundred  ounces 
per  annum  must  be  credited  to  the  Mount  Morgan  mine  itself)  as 
follows  :  — 


Year. 

Fine  Ounces. 

Year. 

Fine  Ounces. 

1886 

47,957 

1897 

170,368 

1887 

82,338 

1898 

167,933 

1888 

113,704 

1899 

177,422 

1889 

314,356 

1900 

199,262 

1890 

213,372 

1901 

157,099 

1891 

141,685 

1902 

146,906 

1892 

121,514 

1903 

120,758 

1893 

118,291 

1904 

133,195 

1894 

116,295 

1905 

128,975 

1895 

127,793 

1906 

131,939 

1896 

147,853 

1907 

145,774 

Total. 


..Fineozs.  3,119,589 
. .  Crude  ozs.  3,230,569 
Value  about  £13.251,750 


During  1906  the  copper  production  of  the  mine  was  2,567  tons, 
and  during  1907,  4,713  tons.  The  copper  yield  will  probably 
increase  in  future  years.  To  the  end  of  1907  the  mine  had  paid  in 
dividends  some  £7,062,020. 

The  ore  of  Mount  Morgan  varies  greatly  in  character.  Siliceous 
haematite,  a  bluish-grey  quartz,  a  rock  simulating  pumiceous 
sinter,  and  a  certain  quantity  of  kaolinic  matter,  all  have  been 
found  at  the  outcrop.  As  the  sulphide  zone  is  reached,  pyrite, 
and  still  further  in  depth,  chalcopyrite  together  with  pyrite,  is 
met  with.  The  original  surface  of  the  mountain  was  lateritic  in 
appearance,  and  carried  spheroids  of  limonite,  that  in  cavities 
became  quite  stalactitic.  In  places  the  surface  rock  was  stained 
black  with  manganese  oxides.  The  large  quantity  of  kaolinic  matter 
found  at  the  surface  was  derived  partly  from  the  felspars  in  the 
grauwackes  and  partly  from  the  decomposition  of  the  basic  dykes 
that  traverse  the  mountain.  The  cellular  siliceous  ore  covered  on 
the  surface  about  2|  acres  in  extent.     It  was  everywhere  at  least 


336  AUSTRALASIA. 

60  feet  in  depth,  and  reached  a  maximum  depth  from  the  surface 
of  160  feet.  Nevertheless,  nodules  of  unweathered  and  unaltered 
siliceous  rock  full  of  pyrite  were  encountered  at  the  surface.  The 
depth  of  the  oxidation  zone  from  the  surface  varied  between 
considerable  limits — from  180  to  300  feet.  Free  and  visible  gold 
was  encountered  in  considerable  quantities  at  the  outcrop,  but  is 
unknown  in  depth.  This  secondary  surface  ore  often  yielded 
several  hundreds  of  ounces  per  ton,  and  some  blocks  of  the  limonite 
indeed  reached  tenors  of  800  ounces  per  ton.a  The  outcrop  gold 
was  exceptionally  high  in  grade,  thousands  of  ounces  running 
997  and  998  fine.  The  siliceous  and  kaolinic  ores  beneath  the 
outcrop,  but  still  within  the  oxidised  zone,  contained  as  much  as 
43  per  cent,  silver.  In  depth  the  ore  carries  from  2\  to  3£  per  cent, 
copper  and  from  \\  to  8  dwts.  gold  per  ton.  Stains  of  copper  were 
at  times  noticeable  in  the  outcrop  ore.  There  may  thus  in  Mount 
Morgan  be  made  out  four  fairly  distinct  zones  in  the  vertical 
distribution  of  the  gold  content,  viz.  :  (a)  a  rich  surface  zone  with 
free  gold  ;  (b)  a  poor  oxidised  zone  of  cellular  quartz  ;  (c)  an  enriched 
sulphide  (pyrite)  zone ;    and  (d)  a  leaner  pyrite-chalcopyrite  zone. 

Various  hypotheses  have  from  time  to  time  been  held  as  to  the 
origin  of  this  remarkable  deposit.  Dr.  R.  L.  Jack,  in  various 
reports  made  when  little  information  was  available  as  to 
character  of  the  ore  at  the  lower  levels,  advanced  a  geyser 
theory  of  origin.  This  view  he  has  largely  modified  as  a 
result  of  the  examination  of  deeper  workings,  and  in  his  last 
report  on  the  subject  says  :b  "  Consequently  a  period  of  time  has 
elapsed  since  the-  formation  of  the  surface  ores,  long  enough  to 
render  it  almost  inconceivable  that  any  deposit  of  a  '  thermal 
spring  in  the  open  air  '  could  have  remained  undenuded."  The 
short  examination  of  the  Mount  Morgan  deposit,  made  by  the 
present  writer  in  1901,  brought  him  to  the  conclusion  that  the 
occurrence  was  to  be  best  explained  by  the  operation  of  siliceous 
and  auriferous  pyritous  solutions  on,  with  minor  metasomatic 
replacement  in,  a  sandstone  or  grauwacke,  the  impregnation  and 
replacement  taking  place  mainly  in  a  thoroughly  shattered  zone. 
The  cellular  surface  rocks  then  visible  were  apparently  merely 
the  weathering  products  of  an  impregnated,  by  no  means  clean, 
sandstone,  or,  much  more  probably,  a  grauwacke.  The  cavities 
were  certainly  such  as  would  have  been  left  by  the  removal  of  pyrite 
and  by  the  decomposition  of  felspar.  Thus  also  were  formed  the 
abundant  iron  oxides  and  the  kaolin  that  were  found  at  the  surface. 
The  free  gold  also  was  readily  explainable,  on  the  assumption  of 

a  Dunn,  loc.  cit.  inf.,  p.  350. 

h  Jack,  Rep.  Geol.  Surv.  Queens.,  No.  132,  1S9S,  p.  20. 


Pint,.   XII. 


Mount  Morgan,  Queensland. 


Open-cut,  Grasstree  Level,  Mount  Morgan. 


QUEENSLAND.  337 

liberation  from  the  auriferous  pyrite  and  chalcopyrite.  It  is  worthy 
of  note  that  comparatively  little  trace  was  shown  in  the  outcrop 
ores  of  the  great  copper  content  now  known  to  exist  in  depth. 
By  virtue  of  its  siliceous  impregnation  and  of  its  consequently 
superior  powers  of  resistance  to  denudation,  the  ore-mass  was 
differentiated  from  the  adjacent  country,  and  when  discovered 
stood  forth  as  a  hill.  The  period  of  impregnation  was  connected 
with  the  acid  rocks  rather  than  with  the  dolerites.  This  theory  of 
origin,  it  will  be  obvious,  is  essentially  that  suggested  10  years 
before  for  the  deposit  by  Rickard  and  by  Wilkinson/' 

A  recent  geological  report  on  Mount  Morgan  is  that  by  Dunn./; 
This,  though  published  only  in  1905,  was,  however,  written  many 
years  before,  when  the  geological  structure  of  the  Mount  was  but 
imperfectly  understood.  While  it  has  apparently  not  been  modified 
in  view  of  later  developments,  the  development  of  the  enriched 
surface  zone  and  its  relations  to  the  sulphide  bodies  are  nevertheless 
clearly  set  forth,  although,  at  the  same  time,  the  impoverishment 
of  the  lower  portion  of  the  oxidised  zone  and  the  enrichment  of  the 
upper  zone  is  held  to  be  due  to  the  action  of  sea  water/ 

Southern  Fields. — The  Lower  Permo-Carboniferous  gold- 
fields  of  Queensland  include  the  Gympie,  Mount  Shamrock,  Calliope, 
Crocodile  (in  part),  Yatton,  Hodgkinson,  Palmer,  Nebo  (Mount 
Britton),  and  others  of  minor  importance. d  Writh  these  the  present 
author  would,  for  reasons  that  have  already  been  advanced,  also 
include  the  famous  Mount  Morgan  mine.  All,  or  nearly  all,  are 
intruded  by  dioritic  dykes. 

Gympie. — The  Gympie  area,  which  has  given  its  name  to  the 
formation,  may  be  taken  as  the  typical  goldfield.  Its  veins  lie  in 
sedimentary  rocks— -grauwackes,  altered  sandstones,  grey  and 
dark-coloured  carbonaceous  shales,  grits,  conglomerates,  limestones, 
and  breccias.  Amygdaloidal  dolerites,  tuffs,  and  andesites  (the 
Gympie  :'  greenstone  ")  are  found  interbedded  with  the  above, 
while  through  them  are  intruded  much  altered  diorite  and  augite- 
andesite.  From  the  present  point  of  view,  the  important  beds  are  the 
four  so-called  "  slates,"  since  it  is  only  in  or  near  them  that  the 
gold-veins  are  productive.  The  three  upper  beds  are  dark  fine- 
grained shales  and  argillaceous  sandstones  containing  graphite 
and  calcite.  The  lowest  bed  is  a  fine-grained  grauwacke.  The 
upper  three  are  100  to  130  feet  apart,  while  the  lowest  is  400  feet 

a  Rickard  T.   A.,  Trans.  Amer.  Inst.   M.E.,  XX,  1891,  p.   133;     Wilkinson,  C.  S., 
Rec.  Geol.  Surv.  N.S.W.,  II,  1891,  p.  86.  j 

b  Proc.  Roy.  Soc.  Vict,,  XVII,  1905,  p/341. 

c  Loc.  cit.,  p.  354. 

d  Jack,  "  Geology  of  Queensland,"  1892,  p.  76  et  seq. 


QUEENSLAND. 


339 


below  the  third.  Shales  in  the  immediate  vicinity  are  fossiliferous, 
containing  Fenestella,  Spirifera,  Productus  cora,  Pleurotomaria 
carinata,  and  Orthoceras  striatum.  The  total  thickness  of  the  series 
is  more  than  2,000  feet. 

The  auriferous  reefs  strike  north  and  south  with  the  country, 
but  dip  east  at  right  angles  to  the  strata,  thus  crossing  all  the  beds 
of  the  series.  It  is,  however,  only  where  they  intersect  the  above- 
mentioned  "  slate  "  beds  that  they  are  auriferous.  So  well  recognised 
is  the  connection  between  the  deposition  of  gold  and  the  intersection 
of  quartz-veins  that  it  governs  the  course  of  mining  operations  on 
the  field,  and  instead  of  following  down  the  veins  by  vertical  or 
underlie  shafts,  as  would  ordinarily  be  the  case,  a  vertical  shaft  is 


Fig.  106.     Part  of  Section  across  Gympie  Gold  field  {Rands). 

a,  d,  g,  I,  p,  s.  Conglomerates.       b,  e,  k,  o.  Sandstones.       c,  /,  i.  Shale3.       h.  Phoenix  or  Upper  Shales. 

n.  "  First  Bed  of  Slate."     r.  "  Second  Bed  of  Slate."     j.  Angular  grit  (volcanic  ash). 

m.  Green  crystalline  rocks,   q.  Altered  grey-wacke.   t.  Diabase-porphyry,    u.  Hard,  crystalline  greenstone. 

v.  Green  and  purple  chloritic  rock. 

sunk  through  the  vein  or  through  the  carbonaceous  bed  and  a  cross- 
cut driven  west  or  east  respectively  to  the  calculated  horizon  of  inter- 
section of  vein  and  "  slate."  The  veins  are  often  intersected  by 
strike  faults  dipping  with  the  country.  When  these  contain  abun- 
dant graphite,  they  are  known  as  "plumbago  floors,"  and  are  a  source 
of  much  local  enrichment/4 

a  Rands,  Rep.  Geol.  Surv.  Queens.,  No.  52,  1889  ;    Id.,  loc.  cit.,  No.  75,  1891  ;  Id., 
loc.  cit.,  No.  100,  1894  ;  Id.,  loc.  cit.,  No.  166,  1901. 


340  AUSTRALASIA. 

Dr.  Jack  a  has  recorded  a  notable  fact  from  the  deep  workings 
of  the  Scottish  Gympie  mine,  where  a  mass  of  auriferous  quartz  - 
veins  traversing  an  '  intrusive  andesite  '  has  been  discovered. 
In  the  andesjte  were  also  "  floors  "  of  graphite  and  small  masses 
of  slate.  The  andesite  occupies  a  horizon  between  the  top  and 
bottom  of  the  Gympie  slates.  Occasionally  where  the  andesites 
have  come  into  contact  with  the  above-mentioned  "  plumbago 
floors,"  they  suffer  the  same  alteration  to  white  rock  that  is  observed 
in  basaltic  or  doleritic  dykes  intrusive  through  coal  seams. 

Calcite  occurs  as  a  secondary  matrix  in  the  Gympie  veins. 
The  associates  of  the  gold  are  pyrite,  marcasite,  mispickel,  galena, 
sphalerite,  chalcopyrite,  tetrahedrite,  stibnite,  native  arsenic,  and 
tellurides  of  gold  and  silver — forming  an  entirely  characteristic 
andesitic  assemblage.  The  sulphides  are,  however,  rarely  auriferous. 
The  tellurides  noted  are  hessite  and  altaite,  and  occur  very 
sparingly  embedded  in  a  calcite  matrix. b 

The  Gympie  field  to  the  end  of  1907  has  produced  2,374,353 
ounces  fine  gold  worth  £10,086,041.  In  1906  the  yield  was  108,053 
ounces  gold  worth  £458,675,  from  215,680  tons  quartz.  Dividends 
paid  amounted  to  £177,554  ;  more  than  half  the  above  yield  was 
produced  by  two  mines,  the  Scottish  Gympie  and  the  No.  2  South 
Great  Eastern.  In  1907  both  yield  and  dividends  decreased 
considerably. 

Minor  Southern  Fields.— Minor  goldfields  in  Southern 
Queensland  are  Eidsvold,  north-west  of  Gympie,  lying  in  granite 
and  diorite  not  greatly  differing  from  those  of  the  Charters  Towers 
field.  The  reefs  are  quartzose,  and  carry  pyrite,  galena,  and  arseno- 
pyrite.  At  Peak  Downs  an  auriferous  conglomerate  is  associated  with 
Glossopteris  flora,  and  is  therefore  of  Permo-Carboniferous  or  later 
age.  The  auriferous  portion  of  the  conglomerate  is  said  to  contain 
5  to  6  dwts.  per  ton.  At  Kilkivan  the  gold  is  associated  with 
antimony,  and  at  Mount  Biggenden  with  bismuth.  The  last- 
named  deposit  is  remarkable.  It  is  an  irregular  mass  of  magnetite 
bounded  on  the  north  by  slate  and  on  the  south  by  limestone.0 

Dredging,  hitherto  quite  unsuccessful  in  Queensland,  is  still 
being  carried  on  at  Cania,  an  old  placer  field.  The  famous  "  deep 
leads  "  of  the  southern  colonies  are  unknown  in  Queensland,  whose 
yield  of  alluvial  gold  amounts  to  only  about  12,000  crude  ounces 
annually,  by  far  the  greater  part  of  which  (7,343  ounces  in  1906)  is 
produced  from  the  Clermont  field. 

a  Queensland  Govt.  Mining  Journal,  Jan.  14,  1905. 

°  Dunstan,  Ree.  No.  2,  Geol.  Surv.  Queensland,  No.  19G. 

c  Rands,  Rep.  Geol.  Surv.  Queensland,  No.  60,  1890. 


QUEENSLAND. 


341 


The  total  gold  yield  of  Queensland  is   shown  in  the  subjoined 
table  :  — 


Year. 

Fine  Ounces. 

Year. 

Fine  Ounces. 

Year. 

Fine  Ounces. 

end  of  1877 

1,819,104 

1888 

397,972 

1899 

668.227 

1878 

270,554 

1889 

634,605 

1900 

676,027 

1879 

243.475 

1890 

513,819 

1901 

598,382 

1880 

222,441 

1891 

477,976 

1902 

640,463 

1881 

225,431 

1892 

509.541 

1903 

668,548 

1882 

185,009 

1893 

510,342 

1904 

639,151 

1883 

173,460 

1894 

548,595 

1905 

592,620 

1884 

250,127 

1895 

506,285 

1906 

544,636 

1885 

250,137 

1896 

502,146 

1907 

465.882 

1886 

279,488 

1897 

600,949 

1887 

348.890 

1898 

647,487 

Total.. 

15.611.767 

Total  value  of  gold  won  to  end  of  1907 


.     £66,314.528 


NEW    SOUTH    WALES. 

The  majority  of  the  auriferous  areas  of  New  South  Wales  are 
closely  connected  with  the  granitic  masses  of  Permo -Carboni- 
ferous age,  that  form  the  core,  not  only  of  the  chief  mountain  chain 
of  New  South  Wales,  but  also,  as  we  have  already  seen,  of  that  of 
Queensland.  The  gold- veins  may  exist  in  the  granite,  or  in  its 
felsite  or  porphyrite  apophyses  (as  in  North  Queensland),  or  even 
in  dioritic  rocks,  or  they  may  occur  (as  in  Victoria)  in  adjacent 
Devonian  or  Silurian  rocks. 

The  earliest  recorded  discovery  of  gold  in  Australia  was  made 
at  the  Fish  river,  Bathurst,  New  South  Wales,  in  1823,  by  a  sur- 
veyor named  O'Brien.  There  is,  however,  room  for  doubt,  in  this 
case,  whether  the  particles  recorded  as  gold  by  that  observer  were 
really  so,  or  were  mica  or  pyrite.  In  1839,  Count  Strzelecki,  of 
whose  mineralogical  knowledge  there  is  no  question,  found  auriferous 
pyrite  in  the  Vale  of  Clwydd.  Two  years  later  native  gold  was 
recognized  by  the  Rev.  W.  B.  Clarke  in  granites  and  quartziferous 
slates  occurring  west  of  Hartley.  Owing,  however,  to  the  fears 
entertained  by  the  authorities  of  the  unsettling  effect  of  gold- 
seeking  on  the  progress  of  the  colony,  both  these  geologists  were 
induced  for  a  time  to  keep  secret  their  discoveries. 

It  was  not  until  1851  that  E.  H.  Hargraves,  who  had  then  just 
returned  from  the  great  Calif ornian  diggings,  demonstrated  the 
existence  of  gold  in  payable  quantities  in  the  neighbourhood 
of  Bathurst.  Within  a  fortnight  of  the  public  announcement, 
made  in  May  of  1851,  more  than  1,000  men  were  at  work 
in  the  vicinity  of  Hargraves'  find.     The  discovery  had  the  natural 


342  AUSTRALASIA. 

effect  of  encouraging  wide-spread  prospecting,  and  by  the  end  of 
that  year  the  great  alluvial  goldfields,  not  only  of  New  South  Wales, 
but  also  of  Victoria,  were  fairly  well  known. 

Gold  is  widely  distributed  in  New  South  Wales,  occurring 
in  reefs  and  lodes  intersecting  the  Silurian,  Devonian,  and 
Carboniferous  rocks  ;  it  has  also  been  successfully  worked 
in  the  ancient  Permo-Carboniferous  conglomerates  of  Tallawang, 
near  Mudgee,  where  nuggets  weighing  as  much  as  5  ounces 
were  obtained.  Auriferous  alluvial  deep  leads  of  Cretaceous 
age  are  recorded  from  Mount  Brown,  in  the  far  north-west, 
while  those  of  Tertiary  and  recent  ages  are  widely  known  and  have 
long  been  worked.  They  formed,  indeed,  the  earliest  source  of  the 
gold  won  in  the  state.  The  majority  of  the  goldfields  of  New  South 
Wales  occur  along  a  broad,  not  very  well-defined  belt  in  the  high  land 
in  the  eastern  portion  of  the  state,  but  rich  fields  nevertheless  occur 
as  far  west  as  Cobar  and  Wyalong,  and  a  minor  occurrence  is  known 
in  the  far  north-west  of  the  state  at  Tibbooburra,  where  the  gold  lies 
in  veins  that  traverse  the  eroded  Palaeozoic  rocks  where  these  are 
intruded  by  basic  or  other  dykes.  Veins  also  occur  within  the  igneous 
rocks  themselves/* 

Pittman  divides  the  alluvial  gold  deposits  of  New  South  Wales 
into  :  — 

(a)  Recent  and  Pleistocene  alluvials. 

(b)  Beach  sands  along  the  sea-coast. 

(c)  Tertiary  alluvial  leads. 

(d)  Cretaceous  alluvial  leads. 

(e)  Permo-Carboniferous  conglomerates. 

The  marine  beach  sands  are  best  developed  near  the  mouth 
of  the  Richmond  river  in  the  north  of  the  state,  where  black  sands, 
made  up  largely  of  zircon,  ilmenite,  garnet,  and  quartz,  contain 
fine  grains  of  gold,  platinum,  and  cassiterite.  They  are,  as  on  the 
coast  of  north-west  America  and  of  the  south-western  part  of 
New  Zealand,  reinforced  in  bulk  and  in  value  after  storms.  They 
have  been  worked  intermittently  since  1870.  Raised  beaches 
containing  black-sand  seams  with  gold  have  also  been  worked. 
The  gold,  both  the  younger  and  older  deposits,  is,  of  course,  in  a 
state  of  extremely  fine  division.  In  the  raised  beach  deposit  the 
sand  is  so  far  cemented  as  to  require  rough  crushing.  McAuley's 
lead  is  the  only  one  that  has  up  to  the  present  proved  payable. 
Pittman  notes  that  although  the  beach  sands  have  been  tested 

a  Pittman,  "  Mineral  Res.  New  South  Wales,"  Geol.  Surv.  N.S.W.,  1901,  p.  6,  from 
whence  many  of  the  following  details  have  been  derived. 


NEW    SOUTH    WALES. 


343 


along  some  hundreds  of  miles  of  coast  line,  it  is  only  in  the  immediate 
neighbourhood  of  basalt  that  they  have  been  of  economic  value. 
The  Tertiary  alluvial  leads  are  the  remnants  of  ancient  auriferous 
river-gravels  that  have,  from  a  variety  of  causes,  been  preserved 
to  the  present  day.  They  represent  mainly  Pliocene  gravels  and. 
as  might  be  expected,  show  considerable  deviation  in  their  course 
from  the  direction  of  existing  valley  systems.  In  many  cases  the 
Pliocene  gravels  owe  their  preservation  to  having  been  buried 
beneath  a  considerable  thickness  of  basaltic  lava  that,  by  covering 
up  the  valleys  with  their  contained  gravels,  reduced  to  a  great  extent 
the  then  existing  inequalities  in  the  surface.  Such  buried  auriferous 
gravels,  as  well  as  those  formed  by  depression  of  the  valley  bottoms 
below  base-level,  are  termed  deep  leads.  Some  of  these  were 
extremely  rich.  It  is  recorded  that  from  an  area  of  40  by  40  feet 
in  the  North  Lachlan  goldfield  near  Forbes,  no  less  than  1,900 
ounces  gold  were  obtained.  Gold  occurs  in  Tertiary  leads  (as 
also  in  the  Recent  and  Pleistocene  deposits)  at  the  Rocky 
River  goldfield  near  Uralla,  and  also  at  Gulgong,  from 
whence     in     five    years    (1871-1875)    £1,850,000    were     obtained. 


M*  Brown 


Bill.ygoat#    Hill 
Desert  Sandstone 


Fig.  107.    Auriferous  Lead  Overlain  by  Desert  Sandstone,  Mount  Brown  (Piltman). 


Often  at  Gulgong  the  average  gold  content  of  the  "  wash-dirt  " 
was  an  ounce  per  load.  The  lead's  in  the  neighbourhood 
of  Gulgong  are  numerous.  For  these  an  average  width  of  300  feet 
of  gravel  with  a  depth  of  1  to  1|  feet  of  pay-dirt  may  be  taken. 
They  have  for  the  most  part  been  abandoned  on  account  of  the 
great  difficulties  of  working  due  to  inflow  of  water,  difficulties 
that  became  insuperable  when  accompanied  by  increasing  poverty 
of  the  gravels.  Similar  auriferous  alluvial  leads  occur  at  Adelong, 
Albury,  Braidwood,  Grenfell,  Gundagai,  Rockley,  Temora,  Tumbe- 
rumba,  &c.  Some  of  the  famous  Victorian  deep  leads,  as  those  of 
the  Chiltern  Valley,  near  Corowa,  are  believed  to  pass  into 
Southern  New  South  Wales. 

Cretaceous  alluvial  leads  or  buried  channels  occur  in  the  north- 
western corner  of  the    state  at  Mount  Brown,  south  of  Milparinka. 


344  AUSTRALASIA. 

They  dip,  as  will  be  seen  from  the  accompanying  section, 
beneath  the  Upper  Cretaceous  Desert  Sandstone.  Very  rich  gold 
was  obtained  from  the  lead,  including  one  nugget  of  25  ounces  in 
weight.  Similar  Cretaceous  leads  occur  at  Tibbooburra,  25  miles 
further  north,  where  granite  and  Silurian  slates  are  almost  hidden 
beneath  the  Desert  Sandstone.  Here  also  the  auriferous  leads 
dip  beneath  the  Desert  Sandstone.  The  gravels  have  yielded  nuggets 
weighing  15  to  20  ounces.  Another  occurrence  of  much  the  same 
age  and  nature  occurs  at  the  Peak  between  Milparinka  and 
Wilcannia. 

The  largest  nugget  ever  found  in  New  South  Wales  weighed 
1,286  ounces  8  dwts.,  and  was  found  in  recent  gravels  at  Burrandong 
near  Orange."  Perhaps  the  most  interesting  occurrence  of  gold 
in  the  State  from  a  geological  point  of  view  is  that  at  Tallawang, 
about  five  miles  to  the  north  of  Gulgong,  where  conglomerates, 
undoubtedly  to  be  relegated  to  a  position  at  the  base  of  the 
Upper  Coal  measures,  and  therefore  Permo-Carboniferous  in  age, 
were,  in  1875,  successfully  worked  for  gold.  The  occurrence  is  of 
no  great  extent.  Nuggets  up  to  5  ounces  in  weight  were  taken 
from  it,  and  yields  of  from  1  to  15  dwts.  per  ton.  On 
referring  to  Wilkinson's  original  note^  there  appears  to  be 
no  doubt  of  the  placer  origin  of  the  gold.  These  conglomerates 
are,  however,  not  definitely  Carboniferous,  as  stated  by  him,  but 
rather  Permo-Carboniferous,  since  they  are  associated  with  the 
Glossopteris  flora  of  the  Eastern  Australian  Coal  Measures.  The 
conglomerate  has  been  worked  principally  at  Clough's  Gully. 
Several  hundred  tons  of  the  cement  were  crushed,  but  the  deposit 
was  found  to  be  very  irregular  in  tenor.  The  gold  was  coarse, 
remarkably  scaly,  and  water-worn.  This  is  the  only  known 
occurrence  of  payable  alluvial  gold  in  these  measures,  though 
traces  of  gold  had  formerly  been  found  in  the  same  series 
by  the  Rev.  W.  B.  Clarke.  In  the  Gulgong  field  the 
original  source  of  the  alluvial  gold  has  obviously  been  the 
veins  developed,  as  the  field  evidence  shows,  by  the  intrusion 
of  diorites  or  granitic  intrusions  through  the  Upper  Silurian  rocks. 
There  is  thus  apparently  fixed  a  superior  limit  to  the  age  of  the 
New  South  Wales  gold- veins.  The  so-called  Carboniferous  occur- 
rence at  the  Peak  Downs  in  Queensland  is  also  Permo-Carboniferous, 
for  the  cement  beds  there  worked,  as  first  described  by  Daintree, 
are  associated  with  the  typical  Glossopteris  flora. 

a  For  a  complete  bibliography  of  New  South  Wales  gold  occurrences  to  1900,  v. 
Dun,  Rec.  Geol.  Surv.  N.S.W.,  VI,  1900,  p.  187.  < 

b  Wilkinson,  C.  S.,  Ann.  Rep.  Dep.  Mines,  N.S.W.,  1876,  p.  173. 


NEW    SOUTH    WALES. 


345 


The  Kiandra  Deep  Leads  are  described  by  Andrews/' 
They  were  discovered  in  1859,  but  only  the  richer  shallow  alluvials 
were  then  worked.  The  township  of  Kiandra  lies  about  4,600  feet 
aboveT  sea-level,   and   is  subject  in  winter  to  heavy  snowfalls,   a 

Section  of  Working  Face        New  Chum  Hill 


(»atTinSO*     a^D  wincklER  S     Claim 


8 
8 


dS'.l 


Columnar  basalt 
Earthy  lignite  altered  by  basalt- 
Yellow  clay 
Red  and  yellow  sand 


/£  „     —  _r_-_____  — _— _-_~_~_~  -    -~  ~~  -       Red  and  yellow  clay 


Lignite  containing  tree  stems 
Red  and  yellow  clay 


Coarse  red  and 
yellow  sand  layers 


35 


4 
3 


Red  and  yellow  clay 


Lignite  and  black   shales 
containing  numerous 
plant  remains 

Earthy  lignite 
Sand 


14 


*■    &::'j'-'-L^^ 


Auriferous  wash 


Slates,   claysfones.   and  tufts 


Syemtic  'dykes 


Fig.  108.     Vertical  Section  through  Deep  Lead,  Kiandra  (Andrews.) 

feature  unique  in  Australia.  Two  well-defined  leads  occur.  Both 
are  capped  by  basalt.  The  auriferous  wash  is  not  confined  to  a  narrow 
gutter,  but  is  distributed  over  an  uneven  bed,  varying  from  50  to 
100  yards  in  width. 


aN.S.W.  Geol.  Surv.,  Min.  Resources,  No.  10,  1901. 


346 


AUSTRALASIA. 


Dredging  both  for  gold  and  for  tin  has  been  practised  in  New 
South  Wales  for  some  years.  To  the  end  of  1906  this  method  of  gold 
recovery  had  produced  the  following  quantities  of  gold: — a 


Year. 

Crude  Ounces. 

Value. 

1900 

8,882 

£33,660 

1901 

23,585 

89,628 

1902 

25,473 

97,891 

1903 

27,237 

104,303 

1904 

32,345 

123,656 

1905 

35,388 

136,090 

1906 

36,649 

141,101 

Total     . . 

189,559 

£726,329 

The  chief  dredging  area  is  the  Araluen  division,  furnishing 
more  than  one-third  of  the  total  for  1906.  The  average  yield  over 
a  quantity  of  3,425,000  cubic  yards  in  this  division  was  1  -96  grains 
per  cubic  yard.  In  the  Stuart  Town  Division  (on  the  Macquarrie 
river)  1,002,900  yards  were  treated  for  an  average  return  of  6-47d. 
per  cubic  yard,  the  total  value  of  the  gold  obtained  being  £27,044. 
The  Sofala  district  on  the  Turon  river,  a  tributary  of  the  Macquarrie, 
yielded  £12,430.  Other  areas  of  lesser  importance  are  being  dredged 
on  various  rivers  in  the  state,  generally  with  profit.  For  the  whole 
state  in  1906,  22  bucket-dredges  recovered  27,643  ounces  gold 
from  5,992,980  cubic  yards  material,  or  4-33  grains  per  cubic  yard. 
Seven  centrifugal  pump  dredges  treated  1,026,550  cubic  yards  for 
a  return  of  8,345  ounces  or  7  32d.  per  cubic  yard. 

Turning  now  to  the  primary  occurrences,  the  auriferous  veins 
of  New  South  Wales  occur  in  Silurian  and  Carboniferous  rocks,  or 
are  associated  with  granodioritic  outbursts  of  probable  Permo- 
Carboniferous  age.  The  gangue  is  generally  quartz  ;  but  calcite, 
barytes,  and  fluorite  are  occasionally  met  with.  Enormous  masses 
of  vein-gold  have  been  found  and,  of  these,  that  taken  in 
1872  from  Beyer  and  Holtermann's  claim  at  Hill  End  is  probably 
the  largest  mass  of  solid  vein-gold  recorded.  It  weighed  630  pounds 
and  was  valued  at  £12,000. 

Hillgrove. — There  are  several  gold-occurrences  on  the 
eastern  escarpment  of  the  pastoral  upland  New  England  country, 
in  the  north-east  of  New  South  Wales.  The  chief  of  these  is  at 
Hillgrove,  on  Baker's  Creek,  about  20  miles  west  of  Armidale. 

Its  mines  are  situated  on  the  eastern  edge  of  the  main 
plateau,  where  it  is  intersected  by  deep  steep-sided  (32°  slope) 
ravines,    1,400    to    1,500    feet   deep.       The   oldest   rocks    on    the 


aRep.  Mines  Dep.,  N.S.W.,  1906,  p.  24. 


NEW    SOUTH    WALES. 


347 


field  are  altered  slates,  schists,  and  quartzites,  often  much 
contorted."  The  slates  pass  insensibly  into  a  knotted  schist. 
The  sedimentary  rocks  carry  the  auriferous  lodes.  The  eruptive 
rocks  are  basic  granites,  or  rather,  granitites  approaching 
very  closely  in  character  to  quartz-mica-diorites,/j  and  are  divided 
into  four  groups  in  point  of  apparent  age.  The  first  two  and  the 
older  are  unimportant  in  extent  and  in  economic  relations,  but  the 
third  is  largely  developed,  and  to  it  is  to  be  ascribed  the  genesis 
of  the  antimony  and  gold  lodes.  The  last  granitic  intrusion  is  a 
fine-grained  rock  that  has  sent  out  into  the  slates  numerous  felsite 


Fig.  109.     Geological  Sketch  Map  of  Hillgrove  Goldfield  {Andrews). 

1.  Carboniferous   slates,   quartzites,    and   schists.     2.  Fine-grained  granite. 

3.    Coarse-grained  granite  (Carboniferous  ?).     4.  Tertiary  gravel. 

5.  Tertiary  basalt,  overlying  gravels.     6.  Felspar-porphyry  and  felsite  dykes. 

dykes.  The  main  or  third  granite  mass  is  traversed  by  some  of 
the  lodes  that  are  continued  into  it  from  the  slates,  but  the  last 
and  finest  granite  cuts  off  these  lodes  and  is  therefore  younger  in 
age.  The  granitic  massif  developed  at  Hillgrove  forms  also  the  core 
of  the  New  England  ranges.  It  is  Carboniferous  or  Permo-Carboni- 
ferous  in  age.  The  whole  district  was  covered  by  the  great  Tertiary 
basaltic  lava  flows  of  the  New  England  region,  that  filled  up  the 
older  valleys.  The  present  minor  valley  system  is,  therefore, 
Pliocene  and  Post-Pliocene. 

The  slates  of  Hillgrove  have  been  subjected  to  great  strain 
and  are  notorious  among  miners    throughout    Australia   for   their 


a  Andrews,  Min.  Res.' No.  8,  Geol.  Surv.  N.S.W.,  1900,  p.  14. 
6  Loc.  cit.,  p.  23. 


348 


AUSTRALASIA. 


"  kicking  "  propensities,  huge  masses  of  rock  flaking  off  the  walls 
of  the  workings  with  explosive  violence.  In  this  respect  the 
explosions  are  comparable  only  to  the  great  "  air-blasts  "  of 
the  hornblende-schist  of  the  Champion  Reef  on  the  Kolar  field  in 
Southern  India. 

The  lodes  of  the  district  were  originally  worked  in  1877-8  for 
their  antimony   content   alone.       A    considerable  amount  of    this 


PLAN 
North  A_ 


?.  South 


Longitudinal   Section 


B 


Transverse     Sections 


Illustrates  how  the  reet 
may  occur  below  and  yet 
not  outcrop  at  the  surface 


Actual  Section  through      Actual  Section  througli 
North  Shaft  Main  Shaft 


level 
intermediate  level       \  \\\ 


Section  through  No.  1  Winze  N. 

Showing   bottom  of  Saddle  Reef 


r 


Figs.  110-116.     Plan  and  Sections  of  the  Mount  Boppy  Syncijne  (Jaquet). 


metal  is  still  produced.  The  presence  of  gold  in  the  veins  was  not 
suspected  until  1881,  but  for  various  reasons,  it  was  not  until  six 
years  later  that  the  richer  gold-lodes  of  Hillgrove  were  opened  up. 
The  Big  and  Little  Reefs,  among  the  earliest  auriferous  lodes 
discovered,  yielded  exceedingly  rich  outcrop-ore. 


NEW    SOUTH    WALES. 


349 


The  veins  or  reefs  of  Hillgrove  carry  a  well-defined  quartz- 
filling  that  may,  however,  be  prolonged  by  zones  of  barren,  crushed, 
and  brecciated  country,  containing  but  little  quartz.  Slickensides 
and  flucans  are  abundant.  Scheelite,  associated  with  stibnite,  is 
found  in  sufficiently  large  quantites  to  be  of  economic  value.  The 
matrix  of  the  gold  is  generally  quartz,  but  stibnite  is  nearly  always 
present  in  great  quantity.  In  depth,  arsenical  pyrites  is  also  found. 
The  reefs  average  from  12  to  18  inches  in  thickness,  and  may  reach, 
as  in  the  case  of  the  Big  Reef,  a  thickness  of  4  feet.  The 
Eleanora  reef  is  the  largest  in  the  district,  averaging  6  feet 
in  width.  It  accompanies  an  intrusive  dyke,  on  both  sides  of 
which  it  forms  quartz.  The  amount  of  gold  recovered  on  treatment 
of  the  ore  is  about  9  dvvts.  gold  per  ton,  but  the  presence  of 
stibnite  is  prejudicial  to  amalgamation  and  considerable  quantities 
are  left  behind  in  the  tailings. 

Mount  Boppy. — The  Mount  Boppy  goldfield  is  situated  on  the 
western  plains  of  central  New  South  Wales,  25  miles  from  the  Cobar 
copper  field.  Its  chief  producer  is  the  Mount  Boppy  mine,  from 
1905  to  1908  also  the  principal  gold-producing  mine  in  the  state. 
The  lode  was  first  worked  for  copper,  and  gold  in  quantity  was 
discovered  only  about  1899.  The  rocks  are  Silurian  slates  and 
schists.  The  reefs  lie,  according  to  Jaquet/6  at  the  base  of  an  inclined 
synclinal  fold,  analogous  in  most  respects  to  the  "  saddle  reefs  ' 
of  Bendigo.  The  synclinal  axis  pitches  southward  at  high  angles. 
The  eastern  leg  is  much  more  strongly  developed  than  the  western , 
and  forms  the  main  lode.  The  oxidised  ore  is  composed  essentially 
of  quartz  with  iron  oxide,  and  the  unoxidised  of  quartz  with 
pyrite,  arsenopyrite,  galena,  and  blende.  The  gold  is  present 
always  in  a  state  of  extremely  fine  division. 

The  following  table  shows  the  quantity    and  value  of  gold 
obtained  from  this  mine  :  — 


Year. 

Tons  of  Quartz 
Crushed. 

Total  Ounces 
of  Fine  Gold. 

Value,  Sterling. 

1901 
1902 
1903 
1904 
1905 
1906 
1907 

12,440 
10,697 
29,312 
35,378 

51,878 
72,976 
76,339 

6,092-00 
7,815-00 
18,800-92 
21,799-80 
27,884-61 
30,087-48 
31,601-71 

£        s.     d. 

18,780  19  10 

24,211     2  11 

79,723  16    9 

91,460     3     4 

116,433  19  11 

126,229     4     1 

133,121     4     7 

289,020 

144,081-52 

£589,960  11     5 

Rec.  Geol.  Surv.  N.S.W.,  VIII,  1905,  p.  180. 


350  AUSTRALASIA. 

To  the  16th  April,  1908,  there  had  been  paid  in  dividends 
£262,282.  13s.,  or  a  little  less  than  half  the  value  of  the  total  gold 
product.  The  average  tenor  of  the  ore  treated  had  been  almost 
exactly  10  dwts.  fine  gold  per  ton. 

Cobar.  — The  Mount  Drysdale  mine,  25  miles  north  of  Cobar, 
also  works  quartz  reefs  in  Silurian  rocks  (slates,  sandstones,  con- 
glomerates, and  breccias).  The  pay-ore  hitherto  mined  occurred 
in  a  shoot  40  feet  long  and  from  6  inches  to  5  feet  in  width. 

The  Cobar  district,  though  primarily  a  copper  district,  never- 
theless contributes  a  considerable  quantity  of  gold  to  the  total 
produce  of  New  South  Wales.  The  mines  were  opened  up  in  1876, 
but  it  was  not  until  1893-4  that  steps  were  taken  to  ascertain 
definitely  the  amount  of  gold  in  the  copper  ingots.  Of  this  amount, 
no  account  had  previously  been  taken,  and  the  contained  gold  had 
up  to  that  time  been  a  perquisite  of  the  London  buyers  of  Cobar 
copper.  The  sulphides  of  the  Cobar  mine  are  pyrrhotite,  pyrite, 
and  chalcopyrite,  with  only  16  per  cent,  silica.  They  carry  from 
1\  to  3  dwts.  gold  per  ton.  The  country  is  Devonian  or  Silurian 
slate  and  sandstone/* 

Hill  End. -The  Hill  End  goldfield,  some  30  miles  north  of 
Bathurst,  is  situated  near  the  Turon  river,  the  scene  of  vigorous 
and  highly  profitable  gold-washing  in  the  earlier  days  of  the  colony. 
The  rocks  of  the  goldfield  are  dark  fissile  slates,  flinty  altered  clay- 
stones,  and  interbedded  volcanic  tuffs.  From  fossil  evidence  the 
series  is  regarded  as  Upper  Silurian  in  age.  The  strata  have  been 
thrown  into  anticlinal  folds  and  are  intruded  by  quartz-porphyry 
dykes  and  sills.  The  reefs  are  lenticular  and  lie  either  in  the  black 
slate,  or  at  the  contact  of  slate  with  the  igneous  sills,  or  with  the  tuffs. 
They  are  bedded  with  the  country.  The  richest  veins  have  hitherto 
been  found  on  the  eastern  side  of  the  anticline.  On  this  side  also 
were  the  Hawkins  Hill  veins,  from  whence  the  already  mentioned 
huge  gold-quartz  nugget  was  taken  by  Beyer  and  Holtermann. 
The  richest  gold  has  been  obtained  at  contacts  of  slate  and 
sill.  Enrichment  generally  takes  place  when  the  quartz,  which 
ordinarily  forms  the  gangue,  has  been  almost  entirely  replaced 
by  a  white  mica  (sericite).  The  gold  hitherto  obtained  occurred 
in  shoots  in  the  veins.  On  this  field,  in  marked  contradistinction 
to  many  others,  it  was  generally  found  that  shoots  were 
developed  at  corresponding  places  in  all  the  parallel  veins.  The 
shoots  were  worked  to  depths  of  400  to  700  feet.^      A  cross-reef 

"Came,  Min.  Res.  No.  6,  Rec.  Geol.  Surv.,  N.S.W.,  1899,  p.  106. 
b  Pittman,    loc.    cit.,   p.    32. 


NEW    SOUTH   WALES. 


351 


faulting  the  above-describecj  veins  carried  in  depth  rich  arsenical 
pyrites  with  free  gold." 

Hargraves.—  The  Hargraves  goldfield  lies  nearly  20  miles  to 
the  north  of  Hill  End  and  at  an  elevation  of  3,000  to  4,000  feet 
above  sea-level.  Its  rocks,  like  those  of  Hill  End,  are  Upper  Silurian 
(or  possibly  somewhat  younger)  slates  and  tuffs  intruded  by  granitic 
dykes  and  sills.  The  reefs  at  Hargraves  are  saddle-shaped  ;  are 
developed  in  the  folds  of  the  beds ;  lie  conformably  with  the  strata ; 
and  occur  in  a  series  along  an  anticlinal  axis,  one  beneath  another 
at  successive  depths.  They  thus  resemble  in  every  respect  the 
saddle  reefs  of  Bendigo.  The  Hargraves  auriferous  belt  extends 
for  1±  miles  in  length  and  J-mile  in  width.  The  most  important 
line  is  that  along  Big  Nugget  Hill.  It  was  on  this  field  that  a  large 
mass  of  golden  quartz  weighing   106  pounds  was  found  in   1851 


BigNuggetHill 


ndicator 


Fig.  117.     Section  through  Big  Nugget  Hill,  Hargkaves  {Pitt man). 
A.A.A.  Saddle  Reefs.     B.B.  Flat  Reefs. 


by  an  aboriginal  shepherd.  This  discovery  led  to  the  opening  up  of 
an  exceedingly  rich  alluvial  field,  that  was  not  exhausted  until 
the  early  'seventies.  Auriferous  reefs  of  another  kind,  locally 
termed  "  flat  reefs,"  occur  at  Hargraves.  While  these  flat  reefs 
have  been  found  to  be  unpayable  throughout  the  whole  of  their 
extension,  they  nevertheless  contain  extremely  rich  shoots^  especially 
where  they  intersect  a  narrow  band  of  dark-greenish  slate  inter- 
bedded  with  the  country  and  locally  -termed  the  "  Indicator." 
The  indicator  generally  carries  an  exceedingly  thin  quartz-vein. 
The  gold  "  makes"  only  in  the  flat  reefs,  but  is  always  restricted 
to  within  a  few  inches  of  the  plane  of  intersection.  The  general  plan 
of  operations  pursued,  in  prospecting  for  "'  pockets  "  in  the  flat 
reefs,  has  therefore  been  to  trench  along  the  outcrop  of  the 
"indicator." 

Lucknow. — The  Lucknow  mines  are  6  miles  from  Orange  in 
central  New  South  Wales.  Alluvial  leads  (Pleistocene  and  Pliocene) 
were  worked  in  the  vicinity  as  early  as  1863.  The  veins,  whose 
degradation  had  furnished  the  gold,  were  soon  afterwards  discovered. 

aWatt,   Rec.   Geol.   Surv.   N.S.W.,  VI,    1899,  p.   83. 


:}5i' 


AUSTRALASIA. 


They  were  of  great  richness  at  and  near  the  outcrop,  pay-ore 
occurring  in  rich  bonanzas  or  ore-shoots.  For  the  8-year  period, 
1892  to  1899,  the  two  principal  mines  of  Lucknow  (Wentworth 
Proprietary  and  Aladdin's  Lamp)  had  produced  nearly  £800,000 
gold.  The  present  production  is,  however,  unimportant,  and  is 
indeed  largely  obtained  from  the  battery  tailings    left   after   the 


ill 


64-0 


Feet 


entw/rth     extn 


ic  if1  **  ■f      At'? 

,P'     ,       1e  >w"<%T    A,  <.UhclE  Tom  Sua 

1  5  (1  ^^V      K       .  <*fiCfORM  SH. 


Ma.  v  Shaft 


/ 


/- 


How 


*r<f  ,/ein 


ewtr*  vet"     "'-%,.  ^ 


yeifCdttu^/  Point  Shaft 


<r 


WENTWORTH 


/./■*    *e'n~~^:yr      kSuauKOCK  S*S'T 


!v* 


PROPRIETARY-        C° 


l/s 


IC32)  ax 
Fig.   118.     Plan  of  Lucknow  Goldfield  (Pittman). 


treatment  of  rich  ore.  The  Lucknow  ore-bodies  are  somewhat 
remarkable.  They  are  invariably  found  as  shoots,  pipes,  or  bunches 
of  ore  at  or  near  the  junction  of  a  number  of  east  and  west  veins 
with  a  north-west  and  south-east  main  fissure,  which  is  often 
vertical,  but  generally  dips  north-east  at  60°.  The  hanging-wall 
of  the  "  main  fissure"  is  a  mottled  dark-green  and  white  serpentine, 


NEW    SOUTH    WALES.  353 

the  foot-wall  greenish-grey  augite-andesite.0  Occasionally,  augite- 
andesite  forms  both  walls  of  the  "  main  fissure,"  but  when  this 
is  the  case  no  ore-bodies  are  developed.  Three  hundred  feet  or  less 
to  the  north-east  of  the  main  fissure  the  augite-andesite  again 
appears.  The  serpentine  is  therefore  merely  a  band  with  a  maximum 
width  of  300  feet.  It  is  believed  to  have  originated  from  the  decom- 
position of  the  augite-andesite. b  Nephrite  or  jade  has  also  been 
found,  but  only  as  a  narrow  band  a  foot  or  so  in  width,  lying  between 
the  ore-body  and  the  serpentine  hanging-wall.  The  east  and  west 
veins  in  the  footwall  andesite  are  never  known  to  cross  the  main 
fissure,  although  no  less  than  17  of  them  have  been  worked.  They 
are  generally  vertical  or  dip  at  a  high  angle,  and  vary  in  width 
from  a  few  inches  up  to  6  feet  or  more.  They  have  a  banded 
structure,  enclose  fragments  of  country  (augite-andesite),  and 
carry  a  gangue  of  quartz  which  on  approach  to  the  main  fissure 
and  to  the  serpentine  is  replaced  by  calcite,  the  matrix  in 
particular  of  the  rich  ore-shoots.  In  the  lower  levels,  at  least, 
the  quartz  gangue  is  never  payable.  The  gold  in  the  calcite  is 
either  free  or  occurs  in  mispickel.  Ore-bodies  unconnected  with 
the  east  and  west  veins  have  never  been  found. 


■:"-::vSV-. 

fast    and      West     >■    >/  •    '  •  .c 

Quartz     ^j      Vein     »■    Xj    *  \   '    /9".  . 

!.*•*■    *■      l.       >■   X   •  ;  •.  V-.-. 

1  L         rf        X        X         l\.^.-£ 

j.,..  >  .ft     h/^i-3-     jR.„:  ".- 


tn 1 1 nninif  Ore  bodies  >.        L     x  <^   l    i. 

Fig.  119.     Plan"  showing  Details  of  Occurrence  of    Ore-bodies    at 

Lucknow  (Pittmun). 

The  ore-bodies  are  developed  as  follows  :  — 

(a)  Shoots  or  pipes  along  the  junction  of  the  quartz-veins 
with  the  main  fissure. 

(b)  As  bunches  extending  horizontally  along  the  main  fissure 
for  a  length  of  from  20  to  50  feet,  but  always  starting  from  the 
toe,  or  plane  of  contact,  of  a  quartz-vein  with  the  main  fissure. 

"Httman,  Rec.  Geol.  Surr.,  N.S.W.,  VII,  1900,  p.  3. 
"  Loc.  cit.,  p.  4. 
Y 


354  AUSTRALASIA. 

(c)  As  "  droppers  "  from  the  footwall  of  the  main  fissure. 

{(I)  As  shoots  in  the  east  and  west  veins  (but  only  near  their 
junction  with  the  main  fissure)  where  calcite  replaces  the  quartz 
for  a  short  distance. 

The  gold  was  free  in  the  upper  zones,  but  in  depth  it  lies  in 
auriferous  mispickel  that  is  associated  with  metallic  antimony  and 
often  with  stibnite.  In  the  lowest  levels  pyrrhotite  replaces  the 
mispickel,  and  the  replacement  is  accompanied  by  a  corresponding 
falling  off  in  the  tenor  of  the  quartz.  The  mispickel  occurs  in 
characteristic  stellate  crystals  that  may  contain  50  to  500  ounces 
gold  per  ton.     The  bullion  is  worth  £3.   10s.  per  ounce. 

Lyndhurst — The  Lyndhurst  goldfield  is  in  the  Bathurst 
district,  8  miles  west  by  south  of  Carcoar.  The  country  is  a  sedi- 
mentary series  of  probable  Lower  Silurian  age,  and  consists  of 
bluish-grey  claystones  alternating  with  beds  of  a  highly  altered 
siliceous  and  pyritous  rock  that  when  thin  forms,  or  when  thick 
contains,  the  ore-bodies.  The  sedimentary  rocks  have  been  intruded 
by  hornblendic  granite,  and  by  dykes  and  sills  of  diorite  that  are 
apparently  off -shoots  from  the  granite  massif. a  Another  series  of 
dykes — in  this  case  of  augite-andesite — is  also  found  within  the 
auriferous  area.  Small  lenticular  masses  of  bluish-grey  limestone 
are  often  associated  with  the  Lyndhurst  ore-bodies.  The  thickness 
of  the  claystones  and  of  the  intercalated  ore-bodies  varies  from  that 
of  a  sheet  of  paper  up  to  20  feet.  In  the  three  principal  mines  the 
productive  ore-bodies  have  been  found  only  in  association  with 
dykes  of  diorite  and  augite-andesite,  and  these  intrusions  appear 
therefore  to  have  had  some  genetic  connection  with  ore-deposition. 
The  ore-bodies  are,  as  has  already  been  seen,  confined  to  hard 
intercalated  beds.  These  were  originally  tuffs,  but  have  subse- 
quently been  largely  altered  by  siliceous  sulphide  impregnations. 
The  tuffs  are  regarded  by  Pittman6  as  representing  original 
submarine  tuffs  and  flows,  much  broken  and  disturbed  by  steam 
injections  while  still  in  the  plastic  state.  The  normal  process  of 
replacement  of  calcareous  tuffs  by  silica  and  pyrite  is,  however, 
quite  competent  to  produce  the  appearance  of  friction  or  of 
deposition-brecciation.  The  Lyndhurst  occurrences  in  this  respect 
show  considerable  analogies  with  those  of  Newman  Hill,  Rico, 
Colorado.  The  bedded  auriferous  deposits  cover  about  500 
acres.  Three  ore-beds  averaging  10  to  11  feet  in  thickness,  and 
separated  by  two  claystone  beds  of  15  feet  and  3  feet  respectively 
in  thickness,  are  definitely  knoMn.    The  value  of  the  ore  varies  from 

"  Pittman,    Rec."   Geol.    Surv.    X.S.W.,   VII,    1900,   p.    9. 
b  Loc.  fit,,  p.   13. 


NEW    SOUTH    WALES. 


355 


3  dwts.  to  2  ounces  gold  per  ton.  The  sulphides  present  are  mispickel, 
pyrrhotite,  and  pyrite. 

Wy along.—  The  Wyalong  field,  in  central  New  South  Wales, 
between  the  Lucknow  and  Murrumbidgee  rivers  and  on  the  same 
parallel  of  latitude  as  Sydney,  lies  in  the  heart  of  a  scrub-dotted 
plain  intersected  by  low  ridges.  Gold  was  not  discovered  in  this 
district  until  August,  1893,  but  from  that  month  to  the  end  of  1906 
the  mines  had  produced  237,870  tons  ore  for  351,284  ounces  gold 
worth  £1,365,360.  It  will  thus  be  seen  that  the  general  grade  of  ore 
treated  is  comparatively  high,  averaging  indeed  1|  ounces  per  ton. 
The  ore  sent  to  the  smelters  ranges  from  3  to  20  ounces  per  ton." 
The  deepest  mines  on  the  field  have  reached  depths  of  1,100  and 
1,300  feet  from  the  surface.  The  field  suffers  from  scarcity  of 
water  (the  rainfall  being  only  20  inches  per  annum),  and  this 
difficulty  is  accentuated  by  the  impossibility  of  water-conservation, 
owing  to  the  general  flatness  of  the  country. 

The  auriferous  veins  of  Wyalong6  lie  entirely  within  a  rock 

locally  termed  granite,  but  which  appears  to  be  rather  a  tonalite 

(quartz-mica-diorite)  than  a  granite.     It  has  in  mass  a  distinctly 

gneissose  structure,  that  close  to  the  vein  fissures  develops  into 

well-marked    schistosity.      The    hornblende    and    biotite    have     a 

roughly  parallel  arrangement,  thus  giving  a  banded  appearance 

to  the  rock.    The  felspar,  which  is  entirely  oligoclase,  preponderates 

largely.    There  is  a  little  quartz,  with  a  large  amount  of  hornblende. 

The  ultimate  analysis  of  the  rock  is  as  follows  : — c 

Moisture  at  100°  C 0-13 

Combined  water       ..          ..          ..          ..          ..          ..  0-73 

Silica  (Si02) 58-93 

Ferric  oxide  (Fe203)          1-73 

Ferrous  oxide  (FeO)            5-01 

Manganese  oxide  (MnO)     .  .          . .          . .          . .          . .  Trace. 

Alumina  (A1„03) 17-48 

Lime  (CaO) 7-08 

Magnesia  (MgO)       ..          ..          ..          ..          ..          ••  4-33 

Potash  (K20)    '        1-34 

Soda  (Na20) 2-91 

Titanic  oxide  (Ti02)           0-52 

Vanadium  pentoxide  (V2Os)        ..  ..  ..     Strong  trace. 

Phosphorus  pentoxide  (P20.)       ..          ..          ..          ..  0-14 

Sulphide  trioxide     . .          . .          . .          . .          . .          . .  Absent. 

100-33 
The  rock  is  therefore  a  quartz-mica-diorite  and  may  be  compared 
with  the  tonalite  of  Charters  Towers,  the  petrological  features  of 
which  field  are  indeed  closely  paralleled  at  Wyalong. 


«Ann.  Rep.   Dep.  Mines.,  1906,  p.  13. 

6  Watt,  Min.  Res.,  No.  5,  Geol.  Surv.,  N.S.W.,  1899,  p.  15. 

c  Watt,  loc.  cit.,  p.  14. 


35G  AUSTRALASIA. 

The  alteration  due  to  crushing  and  to  subsequent  percolation 
of  passing  waters  proceeds  far  into  the  vein-walls,  which  are  occa- 
sionally silicified.  The  country  of  Wyalong  has  been  weathered 
to  great  depths  by  meteoric  waters,  and  in  the  early  days  of  the 
field  was  worked  to  a  depth  of  150  feet  by  pick  and  shovel  alone. 

Sedimentary  rocks  (Upper  Silurian  ?)  have  a  very  small 
development  in  the  neighbourhood  of  Wyalong.  They  are  repre- 
sented, but  lie  about  2  miles  to  the  east  of  the  auriferous  area. 
They  are  schistose  slates  and  quartzites,  that  are  associated  with 
possibly  intrusive  diorites,  large  areas  of  which  have  been  metamor- 
phosed to  hornblende-schists.  The  quartz-mica-diorite  of  the 
field  is  considered  by  Watt  to  be  younger  than  both  the  schistose 
diorite  and  the  sedimentary  rocks.  The  veins  occur  in  zones  of 
crushed  granite  that  are  often  8  to  10  feet  wide,  and  more  or  less 
parallel  in  strike.  They  are  contained  within  an  area  of  1\  square 
miles.  Some  8  to  10  such  zones  are  known.  The  veins  within  the 
crushed  granite  zones  are  on  the  whole  small,  running  from  a  few 
inches  to  \\  feet.  They  are  lenticular  and  are  often  highly  slicken- 
sided.  Quartz  is  the  ordinary  vein  filling.  Reddish-brown  opal 
is  also  present.  It  is,  however,  always  restricted  to  the  upper 
oxidised  zone,  and  carries  fairly  large  grains  of  free  gold.  In  depth 
the  gold  is  exceedingly  fine,  and  is  associated  with  pyrite,  and 
smaller  quantities  of  galena,  mispickel,  and  blende.  Even  in  the 
upper  oxidised  zone  the  gold  is  fine,  especially  in  the  "ironstone" 
or  gossan.  There  has  thus  obviously  been  no  appreciable  actual 
secondary  surface  enrichment,  the  outcrop  gold  being  apparently 
merely  a  residual'  deposit  from  the  decomposition  of  pyrites. 
Owing  to  the  general  flatness  of  the  land  surface,  the  fineness  of 
the  gold,  and  the  very  small  rainfall,  no  alluvial  deposits  have 
been  formed  at  Wyalong. 

Mitchell's  Creek.— The  Mitchell's  Creek  goldfield  is  in  the 
Mudgee  district,  9  miles  from  Wellington.  The  rock  of  the  district 
is  a  Silurian  slate  that  is  intruded  by  numerous  augite-andesite 
dykes."  The  principal  reef  (Mitchell's)  lies  within  an  augite- 
andesite  dyke.  It  varies  in  width  from  3  inches  to  5  feet,  and  in 
value  from  5  to  13  dwts.  per  ton.  Dick's  reef  is  also  in  diorite 
(augite-andesite) . 

Yalwal. — The  Yalwal  field  is  on  the  eastern  side  of  the 
Australian  Corderilla,  some  8  miles  from  Nowra,  on  the  Shoalhaven 
river.  Alluvial  gold  had  long  been  worked  in  the  vicinity,  but  the 
reef  gold  remained  untouched  until  1873.  The  veins  have  since 
been  mined  spasmodically,  but  often  successfully.     The  ore-bodies 

"  Macdonald,  W.  F.,  Trans.  Inst.  Min.  Met.,  XV,  1906,  p.  526. 


NEW    SOUTH    WALES. 


357 


occur  as  impregnations  in  indurated  siliceous  slates,  quartzites, 
and  conglomerates,  associated  with  rhyolitic  and  basic  lava  flows, 
all  of  probable  Devonian  age.  These  are  overlain  unconformably 
by  the  Upper  Marine  Beds  of  the  Permo-Carboniferous  system. 
The  Devonian  rocks  were  intruded  in  Carboniferous  times  by 
granites  and  by  quartz-felspar-porphyries."  No  reefs  with  well- 
defined  walls  exist  in  the  district,  but  veinlets  of  quartz  traverse 
the  quartzites  and  silicified  slates.  Rich  deposits  and  seams  of  gold 
are  found  near  these  veinlets,  while  all  the  rocks,  including  the 
conglomerates,  contain  small  quantities  of  gold  (1  to  2  dwts.  per 
ton).  The  country  is  sparsely  impregnated  with  pyrite.  The  rock 
is  in  general  much  silicified.  Below  the  water-level  are  huge  masses 
of  pyrite  and  arsenopyrite.     The  quartz  is  ordinarily  chalcedonic. 


Fig.  120.     Sketch  Section  of  the  Yalwal  Goldfield  {Pittman). 

A.  Nowra  grits    (Permo-Carboniferous).     B.  Shales    and    conglomerates    (do.).     C.  Devonian 
quartzites,  conglomerates,  and  silicified  slate3  containing  gold. 

The  gold  is  exceedingly  fine.  Free  gold  occurs  only  in  the  oxidised 
zones.  It  is  clear  that  the  gold  was  originally  carried  in  the  sulphides. 
Ore-deposition  is  associated  by  Andrews  with  the  Carboniferous  (?) 
granitic  intrusions.  Mining  and  milling  costs  are  lower  at  Yalwal 
than  elsewhere  in  the  State,  the  total  costs,  as  long  ago  as  1900, 
amounting  to  less  than  8s.  per  ton.  This  low  figure  is  due  to  cheap 
extraction  from  an  open-cut  that  lies  at  a  considerable  elevation 
above  the  crushing  mill. 

In  the  rhyolitic  lavas  (Devonian  ?)  of  Grassy  Gully,  five  miles 
from  Yalwal,  gold  has  been  found  in  chalcedonic  quartz  in  a  devit- 
rified  rhyolitic  glass.  The  pay-ore  is  apparently  an  irregular 
cementation  of  the  country,  and  always  contains  pyrite.  The 
genesis  of  the  ore-deposits  appears  to  be  similar  to  that  observed 
at  Yalwal.& 


a  Andrews,  Min.   Res.,  No.  9,  N.S.W.  Geol.  Surv.,   1901,  p.   14. 
6  Jaquet,  Rec.  Geol.  Surv.  N.S.W.,  VII,  1900,  p.  18. 


358 


AUSTRALASIA. 


Panhula. — At  Panbula  and  Wolumba,  in  the  extreme  south- 
east corner  of  the  State,  gold  occurs  in  a  rhyolitic  felsite  that  contains 
numerous  spherulites.  Free  gold  is  found  in  and  adjoining  the 
thin  fissures  with  which  the  felsite  is  seamed.  The  gold  is  exceedingly 
fine  and  the  country  is  thoroughly  impregnated  with  pyrite.  A 
notable  local  enrichment  is  observed  in  the  vicinity  of  a  quartz- 
vein,  locally  known  as  the  "  Pilot  Reef  "  or  "  Indicator."  This 
reef  has  been  traced  for  nearly  a  mile.  It  is  often  pyritous  but  is. 
itself  always  barren/' 


Figs.  121  and  122.     Plan  and  Section  of  Reef,  Panbula 
Goldfield  {Power). 

A.  Rhyolite  country.       B.  Hanging-wall.      C.  Quartz-vein-. 
D.  Shattered  zone,  with  fragments  of  rhyolite  cemented  by  quartz. 


From   1851   to    1907  inclusive  the  gold  yield  of  New    South 
Wales  has  been  :  — 


Year. 

Cm  ie  Ounces. 

Value. 

1851-1900 

13.118,356 

£48,422,001 

1901 

213.689 

737.164 

1902 

190.316 

684,97<  1 

1903 

295,778 

1,080,029 

1904 

324.996 

1,146,109 

1905 

328,747 

1.165,013 

1906 

302,556 

1 .078,866 

1907 

247,363* 

1.050,730 

14,991,801 

£55,364,882 

*  Fine  ounces. 


"  Carne,  Ann.  Rep.  Dept.  Mines.  N.S.W.,  1896,  p.  100. 


359 


VICTORIA. 

The  yield  of  gold  from  Victoria,  the  smallest  of  the  States 
of  Australia  with  the  exception  of  Tasmania,  has  been  more 
than  half  that  of  the  Commonwealth.  Its  gold-mining  history 
may  be  said  to  date  from  the  "  rush  "  to  Buninyong,  though  gold 
had  earlier  in  the  year  (1851)  been  discovered  at  Clunes  and  at 
Anderson's  Creek.  Discoveries  rapidly  followed  from  widely- 
separated  points  ;  from  Pleasant  Creek,  Ararat,  Avoca,  Tarran- 
gower,  Bendigo,  Mclvor,  Beechworth,  &c,  and  a  general  "  rush  ' 
to  the  southern  Eldorado  took  place  that  has  been  paralleled  in 
history  only  by  the  mad  race  to  California  of  some  three  years  earlier. 
In  the  decade  from  1852  to  1861  the  enormous  amount  of  25,369,436 
ounces  gold,  worth  more  than  £100,000,000  sterling,  had  been 
produced.  The  year  of  greatest  production  was  1856,  when  3,053,744 
ounces  were  obtained.  Among  the  earlier  returns  are  included 
some  of  the  largest  nuggets  known  ;  of  these  the  weights  of  the 
chief  are  shown  below  :  — 


Name. 

Locality. 

Date  of  Discovery. 

Weight. 

Ounces. 
Gold. 

Approx. 
Value. 

Welcome  Stranger 

Moliagul 

5  Feb.,  1869   . . 

2,516 

£9,553 

Welcome 

Bakery  Hill. 

Ballarat . . 

15  June,  1858  .  . 

2,195 

9,325 

Blanche  Barkly 

Kingower 

27  August,  1857 

1,743 

6,915 

Canadian 

Canadian  Gully, 

Ballarat.  . 

31  Jan.,  1853   .  . 

1,319 

5.532 

Dunolly  (2  nuggets)    .  . 

Dunolly 

1857.. 

1.364 

5,500 

Sarah  Sands 

Canadian  Gully.. 

18  Sept.,  1854  . . 

755 

3,200 

Since  the  first  discovery  of  gold  the  total  yield  of  Victoria  to 
the  end  of  1906  has  been  69,202,178  crude  ounces  (65,096,487  fine) 
worth  £276,516,978. 

Rocks  of  doubtful  Archaean  and  Cambrian  age  form  the  base- 
ment series  of  the  Victorian  strata.  Important  auriferous  quartz- 
veins  are  not  developed  in  these,  but  lie  for  the  most  part  in  the 
overlying  sharply-folded  Ordovician  slates  and  sandstones.  These 
have  been  separated  from  the  overlying  Silurian  mainly  by  aid 
of  their  contained  graptolites.  The  Silurian  rocks  also  contain 
auriferous  quartz-veins.  The  numerous  granite  intrusions  into  the 
Palaeozoic  sediments  are  for  the  most  part  of  a  fairly  basic  type,  as 
has  been  well  shown  by  Hogg,-'  who  calls  attention  to  the  relatively 
abundant  occurrence  in  these  rocks  of  plagioclase  felspar  ;  and 
many  of  his  rocks  obviously  fall  within  the  group  of  granodiorites, 


«Proc.   Roy.   Soc.  Vict.,  XIII,  N.S.,   1901,  p.  214. 


360 


AUSTRALASIA. 


as  outlined  by  Lindgren.a  According  to  Howitt,  quoted  by 
Gregory,**  the  granitoid  rocks  of  Victoria  may  be  divided  into  a 
pre-Silurian  granite  and  a  Devonian,  or  at  least,  pre-Carboniferous 
granodiorite.  Limburgite  dykes  of  Tertiary  age  are  numerous, 
but  have  exercised  little  or  no  effect  on  auriferous  deposition. 

The  goldfields  of  the  Ordovician  rocks  of  Victoria  are  :  Bendigo, 
Ballarat,  Castlemaine,  Maldon,  Daylesford,  Blackwood,  Berringa, 
Steiglitz,  dunes,  Creswick,  Maryborough,  Dunolly,  Wedderburn, 
Ingle  wood,  Avoca,  Ararat,  Stawell,  and  St.  Arnaud  on  the  west, 
with  Chiltern,  Rutherglen,  Myrtleford,  Harrietville,  Dargo, 
Bulumwaal,  Dart  River,  &c,  on  the  east. 

The  Silurian  quartz-veins  lie  in  shales,  sandstones,  mudstones, 
and  limestones,  at  Walhalla,  Wood's  Point,  Foster,  Tanjil,  Yarra 
Basin,  Reedy  Creek,  Rushworth,  Heathcote,  and  Upper  Goulburn 
Basin/ 

In  addition  to  the  foregoing  there  are,  in  the  Benambra  and 
Bogong  counties  in  the  extreme  north-east  of  the  State,  goldfields, 
or  rather  gold  occurrences,  in  metamorphic  rocks  (schists  and 
gneissic  granite)  of  possible  pre-Cambrian  age.  Veins  may  also 
occur  in  the  intrusive  granitoid  rocks. 

The  principal  producing  districts  of  Victoria  were  for  1906  :  — 


Bendigo 

Ballarat 

Beechworth 

Castlemaine 

Gippsland 

Maryborough 

Ararat  and  Stawell 


ounces. 

221.187 
164,065 
134,812 
99,386 
97,180 
80,267 
24.899 


The  principal  producing  mines  were  : — 


Ounces. 

Long  Tunnel,  Walhalla 

25,294 

Long  Tunnel  Extended,  Walhalla 

20,345 

New  Moon,  Bendigo 

15,493 

South  New  Moon,  Bendigo 

13.330 

New  Argus,  Bendigo 

13.930 

Virginia,  Bendigo 

12,872 

aAmer.  Jour.  Sci.,  IV,  IX,  1900,  p.   2C9. 

h  Mem.  Geol.  Surv.  Vict.,  No.   1,  1903,  p.  42. 

c  Kitson,  Victorian  Year  Book,   1905,  p.  519. 


VICTORIA.  361 

Gippslaiid. — Gippsland,  in  the  south-eastern  region  of  Victoria, 
contains  several  mining  districts,  the  most  prominent  of  which 
are  Walhalla  (Long  Tunnel)  ;  Jericho  (New  Loch  Fyne,  &c.)  ; 
Bulumwaal  or  Boggy  Creek  ;  and  Omeo.  In  the  Walhalla  district 
the  reefs  are  in  or  are  associated  with  granitoid  dykes.  The  main 
auriferous  belt  commences  south  of  WaDialla  and  runs  north- 
north-west  through  Jericho,  Matlock,  Wood's  Point.  Enoch's 
Point,  and  Jamieson.  At  Bulumwaal,  eight  miles  north  of  Bairnsdale, 
gold-quartz  veins  are  found  in  the  intrusive  granitoid  rock.  The 
Ordovician  series  in  the  Gippsland  area  is  partly  overlain  by 
Devonian  or  at  least  Upper  Palaeozoic  strata  which  carry  a  few 
gold-quartz  veins  of  importance,  but  which  are  nowhere  else 
in  Victoria  known  to  be  auriferous.  The  evidence  for  the 
Devonian  age  of  these  upper  beds  is,  however,  very  slender. 
The  Ordovician  rocks  are  there  intruded  by  massive  diorite 
dykes  that  strike  and  dip  with  the  country.  Walhalla  is  situated 
at  the  bottom  of  a  deep  ravine.  Its  veins  were  discovered  in 
1863,  and  the  famous  Long  Tunnel  Company  was  registered  in 
July  of  that  year.  The  reefs  were  very  rich  at  the  surface.  The 
Long  Tunnel  has  been  one  of  the  richest  quartz  mines  in  Australia. 
The  mine  was  long  worked  from  a  shaft  sunk  from  a  point 
575  feet  within  the  tunnel,  and  the  lode  has  been  followed  for  a 
depth  of  4,100  feet  on  the  dip.  To  the  middle  of  1908  it  had 
crushed  648,385  tons  for  765,246  ounces,  and  had  paid  in 
dividends  £1,270,200.  To  the  end  of  1898  the  reef  (Cohen's)  on 
which  the  Long  Tunnel  mine  is  worked  had,  in  the  various 
mines  of  Walhalla,  yielded  2,000,000  ounces.  The  adjacent  Long 
Tunnel  Extended  Company,  formed  in  1870,  and  working  on  the 
same  reef,  has  produced  gold  to  the  value  of  £1,530,000,  and  has 
paid  in  dividends  £770,880.  To  the  2,200  feet  level  the  Cohen's 
reef  was  associated  with  a  diorite  dyke. 

The  Matlock  field  lies  in  the  dividing  range  of  south-eastern 
Victoria  and  contains  one  well-known  mine,  the  New  Loch  Fyne, 
working  on  a  great  diorite  dyke  some  300  feet  wide  and  intersected 
by  numerous  quartz-veins.  The  whole  of  the  dyke  is  highly  pyritous 
and  yields  milling  ore.  To  the  end  of  1898,  the  New  Loch  Fyne 
had  yielded  49,889  ounces  from  50,247  tons  quartz,  and  had  paid 
£96,200  in  dividends.  A  number  of  fields  of  minor  importance  are 
being  worked  in  Gippsland. 

Beechworth. — The  Beechworth  district  includes  the  gold- 
fields  of  Rutherglen,  Chiltern,  Beechworth,  Yackandandah, 
Bethanga,  WTandilgong,  Harrietville,  Alexandra,  Gaffney's  Creek, 
Wood's  Point,  and  Big  River.  This  district  lies  between  the  Murray 
river  and  the  dividing  range,  and  for  the  most  part  east  of  the  Ovens 


362 


AUSTRALASIA. 


river.  Its  gold  is  mainly  derived  from  the  great  deep  "  leads  ' 
buried  beneath  Upper  Tertiary  basaltic  flows.  The  principal  reefing 
divisions  within  the  district  are  at  Bright,  Harriet ville,  and  Gaffney's 
Creek.  In  the  last,  the  gold-quartz  veins  occur  as  flat  L  floors' 
in  diorite  dykes  that  run  for  miles  through  the  country,  their  strike 
nearly  coinciding  with  that  of  the  Ordovician  rocks.  The  dykes 
attain  a  maximum  width  of  some  200  feet. 

While  no  clear  evidence  of  the  relation  of  the  goldfields  of 
Victoria  to  the  quartz-mica-diorite  (granodiorite)  masses  of  post- 
Silurian  age  is  available  from  the  two  leading  goldfields  of  Ballarat 
and  Bendigo,  this  evidence  is  amply  furnished  by  some  of  the  minor 


.peaLmv- 

,mmw 


/, 


//. 


/'  ' i states i 


Dyke 
/\7 


Midd/e  "■  Reef 


-// 


3f 


ilk, 


Mm  ■ 

J 


to- 


'  ll'l  fi,  t/MP^  ■^J^^L^^tf^^/™.'""*  Cherry*  *ef 


1  /  .'  :/,,'  ■ ■/ '// 1 1  Level  of  /fiver 


U,  i " i/i" 

Fig.  123.     Auriferous  Quartz  "  Floors  "  ix  Morning  Star  Dike.  Wood's  Point  ( WhUelaiv). 

(Scale  about  160  feet  to  the  inch.) 

fields.  Of  these,  Wood's  Point"  is  perhaps  the  best  example.  Here, 
Lower  Ordovician  rocks  are  intruded  by  various  types  of  quartz- 
mica-diorites.'J  In  the  latter  auriferous  deposition  has  taken  place, 
the  gold  occurring  generally  in  quartz-floors  in  the  dykes.  The 
thickness  of  the  floors  varies  directly  with  the  width  of  the  dykes, 
the  wider  dykes  (over  50  feet)  possessing  the  thicker  floors  (1  to  10 
feet).  Pyrite  and  galena  ordinarily  accompany  the  gold.  In  the 
principal  dyke  (the  Morning  Star)  the  richest  gold  is  obtained  near 
the  contact  of  dyke  and  slate. 

"  Wbitelaw,  Mem.  Geol.  Surv.  Vict.,  1905,  Xo.  3,  p.  11. 
''  Gregory,  loc.  cit.  sup.,  p.  32. 


VICTORIA. 


363 


Ballarat.— Ballarat  lies  70  miles  west-north-west  of  Melbourne. 
Its  rocks  are  thin-bedded  unfossiliferous  shales  and  sandstones, 
striking  practically  north  and  south  and  dipping  generally  to  the 
west,  though  the  dip  is  often  reversed  owing  to  faulting."  The 
nearest  granitoid  rocks  exposed  are  some  miles  to  the  east  of 
Ballarat,  near  Gong  Gong  Creek  and  Warrenheip.     These  are  later 


Fig.   124.     Sketch  Plan  of  the  Ballarat  Mining  Fif.ld  [Murray). 


in  age  than  the  Ordovician  slates,  and  have  metamorphosed  them 
along  the  immediate  contacts.  Their  metamorphic  influence  does  not 
reach  as  far  as  Ballarat,  though  they  may  be  nevertheless  considered 
partly  responsible  for  the  great  crumpling  to  which  the  sedimentary 
rocks  of  the  region  have  been  subjected.      Sub-acid    felsitic    rocks 


a  Gregory,  Mem.  Geol.  Surv.  Vict.,  Xo.  4.  1907. 


364  AUSTRALASIA. 

are  intrusive  through  the  Ballarat  rocks,  and  are  probably 
to  be  connected  with  the  granitoid  magma.  The  limburgite 
dykes  that  are  intrusive  at  Ballarat  belong  to  a  Tertiary  period 
of  basic  volcanic  activity. 

The  quartz-mines  of  Ballarat  occur  in  three  distinct  areas  : 
Little  Bendigo,  Ballarat  East,  and  Ballarat  West.  The  first-named 
is  situated  to  the  north  of  the  Ballarat  East  section.  Its  vein- 
channels  strike  approximately  north  and  south.  The  principal  is 
the  Monte  Cristo  line— a  band  of  alternating  sandstone  and  slate, 
bounded  by  two  parallel  fault  lines,  and  containing  numerous 
transverse  flat  quartz-veins  that  pitch  slightly  to  the  south  and  dip 
east.    A  central  band  of  slate  is  known  as  the  Jarvis  Indicator/* 

The  Ballarat  West  area  is  covered  by  basalt  and  its  veins 
therefore  do  not  outcrop.  They  were  discovered  by  the  alluvial 
miners  who  had  followed  the  rich  alluvial  leads  beneath  the  basalt. 
The  veins  have  now  been  worked  in  depth  to  2,300  feet.  They 
are  irregular  lenticular  masses  with  many  lateral  and  vertical 
extensions. 

Ballarat  East  furnished  many  of  the  great  gold  nuggets  of  the 
early  'fifties.  Similar  large  nuggets  of  gold  have  been  found  in  the 
underlying  quartz-veins.  One  type  of  vein  in  Ballarat  East  is 
represented  by  almost  horizontal  veins  that  are  auriferous  only 
at  or  in  the  immediate  vicinity  of  their  contacts  with  certain  bands 
of  slate  termed  "  indicators."  Nuggets,  are,  however,  occasionally 
found  within  the  "  indicator  belt,"  but  away  from  the  indicator 
(55  feet  away  in  the  Woah  Hawp  mine).6  The  relation  of  the 
auriferous  pockets  to  the  indicators  appears  to  have  been  realised 
first  in  1871. 

Considerable  discussion  has  arisen  as  to  the  nature  and  origin 
of  the  "indicators."  Rickardc  gives  the  following  excellent 
definition  :  "The  indicator  is  essentially  a  very  thin  thread  of  black 
slate,  which  is  remarkable  on  account  of  its  extraordinary  per- 
sistence, and  also  because  the  quartz  seams  which  cross  it  are 
notably  enriched.  In  places  it  is  so  impregnated  with  iron  pyrites 
as  to  have  the  general  appearance  of  a  sulphide  streak."  The 
indicators  have  long  been  regarded  as  owing  their  black  colour  to 
carbonaceous  material,  which  has  further  been  cited  as  the  reducing 
agent  responsible  for  the  precipitation  of  gold  and  sulphide. 
Bradford  and  Gregory ,d  however,  regard  the  indicators  as  thin 
secondary  seams  developed  along  more  or  less  vertical  lines  in  the 

"  Whitelaw,  Rep.  Dept.  Mines  Vict.,  1901. 

"  Gregory,  loc.  cit.,  p.   12. 

c  Trans.  Amer.  Inst.  M.E.,  XXX,  1900,  p.   1009. 

"-  Loc.  cit.,  p.  13. 


VICTORIA. 


365 


sedimentary  rocks.  The  indicators  as  examined  by  Gregory  are 
of  three  types:  (a)  thin  seams  of  pyrites;  (6)  chloritic  bands; 
(c)  rutile  bands  {e.g.,  the  Pencil  Mark).  The  views  of  Messrs. 
Bradford  and  Gregory  as  to  the  secondary  origin  of  the  indicators 
have  not  found  general  acceptance,  and,  despite  their  evidence, 
the  view  is  still  held  that  the  indicators  represent  interstratified 


Sandstone 


Slate 


Slaty  Sindttoc; 


Quartz 


Tbo  Indicator 


Fig.   125.     Vertical  Section  of  the  "Indicator"  ix  the  New  Normanby  Mine,  Ballarat 

(Richard). 

sedimentary  bands,  the  materials  of  which  are  partly  replaced  by 
pyrite,  chlorite,  and  rutile,  and  that  before,  during,  and  after  the 
formation  of  the  quartz  veins,  the  indicators  were  faulted  and 
disturbed  in  common  with  the  country.  The  various  eccen- 
tricities displayed  by  the  indicators  are  probably  all  to  be  explained 


366 


AUSTRALASIA. 


on  the  latter  assumption.  Under  the  hypothesis  of  secondary 
origin,  it  is  exceedingly  difficult  to  account  for  the  lack  of  fault- 
phenomena  on  the  indicator  walls.  The  typical  indicator  mines 
are  grouped  in  the  southern  portion  of  the  field.  On  them  the 
earliest  gold-mining  was  commenced  in  1854. 

To  the  east  of  the  "  Indicator  "  proper  are  similar  dark  bands 
that  have  exercised  a  like  effect  on  auriferous  solutions.  They 
are  the  "  Eastern  Indicator,"  "  Black  Seam,"  and  "  Pencil  Mark." 
To  the  west  are  the  "  Telegraph  '  and  the  "  Western  Indi- 
cator."   Bradford a  asserts  that  if  rich  gold  is  met  with  at  any 


SCALE  OF  FEET 


GD 


SAND9TOHE 


Fig.  126.     Vertical  Section  of  the  Metropolitan  Lode,  Ballarat  {Richard). 

given  level  on  one  indicator  there  is  then  no  likelihood  of  gold 
occurring  at  the  same  level  in  the  eastern  or  western  indicators. 
In  the  northern  part  of  the  field  the  mines  are  working  quartz- 
lodes  developed  along  fault  planes.  The  greatest  enrichment  has 
taken  place  along  a  strike  fault,  indicated  by  a  clay  seam  resulting 
from  fault-crushing,  and  known  as  the  "  Leather  Jacket." 

The  gangue  of  the  Ballarat  veins  is  ordinarily  a  white  quartz, 
which  is  rarely  laminated.  Much  of  it  may  be  of  metasomatic 
origin.  In  the  fault  fissures  the  gangue  is  often  abrecciated  country 
rock  with  quartz  and  calcite  and  gold,  galena,  blende,  arsenopyrite, 


a  Aust.  Min.  Stand.,  June  1,  1899,  p.  20. 


VICTORIA. 


367 


and  pyrite.  Another  gangue  material  is  a  mixture  of  calcite,  dolomite 
chlorite  and  sericite.  The  average  fineness  of  the  gold  is  about 
974.« 

As  an  instance  of  the  extraordinary  richness  of  the  Ballarat 
alluvials  it  is  stated  that  more  than  £40,000,000  gold  was  obtained 
from  its  older  leads  between  the  years  1851-1868. 

Bendigo  (Sandhurst).— The  goldfield  of  Bendigo,  100  miles 
north-west  of  Melbourne,  lies  in  a  region  of  low  hills.  Placer  gold 
was  discovered  in  1851,  and  was  the  only  source  of  gold  until  1854, 
when  the  gold-quartz  veins  were  opened  up.  The  greatest  yield 
from  Bendigo  was  in  1853,  when  661,729  ounces  worth  £2,646,800 


New  Chum  Line 


Garden  Gully  Line 


*v  Hustlers  Line 


East 


Fig.  127.    Ideal  Section  showing  Main  Lines  of  Reef,  Bendigo  (Rickard). 


were  obtained,  all,  of  course,  from  the  placer  deposits.  Anticlinal 
axes  in  the  Ordovician  strata  are  here  very  prominent,  and  it  is 
along  these  that  the  famous  "  saddle  reefs  "  have  been  developed. 
Numerous  bedded  veins  of  quartz  Have  been  formed  in  the 
saddles,  and  also  in  the  inverted  saddles,  though  the  latter  are  of 
little  economic  importance.  The  former  follow  the  crests  of  the 
anticlines  for  long  distances,  and  are  thickest  at  the  crests,  pinching 
out  in  depth  along  the  "  legs  "  on  either  side.  The  general  strike 
of  the  anticlines  is  north-north-west  and  south-south-east.  The 
veins  lie  along  and  between  beds  of  slate  and  sandstone.  Eleven 
such  parallel  lines  of  saddle  reefs  have  been  distinguished.  Of 
these,  three  have  been  worked  on  an  extensive  scale,  viz.,  New 
Chum,   Garden  Gully,  and  Hustler's.     The  first  has  been  traced 


a  Lidgey,  Rep.  Dep.  Mines,  Vict.,  1894  ;    Don.,  Trans.  Amer.  Inst.  M.E.,  XXVII, 
1897,  p.   57. 


368 


AUSTRALASIA. 


for  a  distance  of  14  miles,  the  second  for  7  miles,  and  the  third  for 
5  miles.  The  greatest  depth  to  which  the  New  Chum  line  had  been 
worked  was,  at  the  end  of  1907,  some  4,343  feet.  At  this  depth 
the  incoming  water  was  very  hot,  and  it  was  found  necessary  to  cease 
mining  operations  at  the  bottom  of  the  winze  that  had  attained 
this  depth  until  the  water  and  adjacent  rock  had  cooled."  The 
anticlines  undulate  considerably  in  longitudinal  direction,  so  that 
their  pitch  is  sometimes  to  the  north  and  sometimes  to  the  south, 
often  indeed  as  steeply  as  20°.      The  anticlinal  axial  planes  are  not 


■\ 


\-  • 


\; 


\ 


\J683  'level 


$m. 


x 


East 


:'^Su*Ni  <±  mo  level 


Fio.  128.     True  Saddle  Reef,  New  Chttji  Consolidated  Mtse, 

Besdigo  (Rickard). 

A.  '"Centre-country"  of  sandstone.      B.  Slate.     C.  Quartz. 

truly  vertical,  but  dip  slightly  to  the  east.  The  saddle  reefs  underlie 
each  other  at  varying  distances  up  to  300  feet  or  more.  Structures 
simulating  saddle  reefs  have  been  found,  and  are  generally  due  to 
cross-Assuring.  In  working  the  saddles,  prospecting  for  lower 
saddles  is  effected  by  sinking  shafts  designed  to  strike  a  "  leg  " 
of  an  underlying  saddle,  from  whence  stopes  are  carried  up  to  the 
crest  of  the  anticline.  The  inverted  saddles  are  both  poorer  and 
smaller  than  the  true  saddles.  The  "  legs  "  generally  thin  away 
to  a  single  thread,  but  sometimes  branch  off,  forming  a  number 


"  Min.  Jour.,  Feb.  29,  1908. 


VICTORIA. 


369 


of  threads.  Occasionally  the  crest  of  the  anticline  is  continued 
upwards  along  a  fault  line  induced  by  tension  along  the  anticlinal 
axial  plane.  The  gangue  is  ordinarily  white  banded  quartz  con- 
taining occasional  horses  of  country.  The  distribution  of  the 
gold  is  irregular.  The  largest  and  richest  body  of  ore  yet  uncovered 
was  found  at  a  depth  of  600  to  700  feet  on  the  Garden  Gully  line. 
The  gold  is  generally  finely  divided,  but  is  sometimes  clearly  visible. 
Pyrite,  blende,  and  galena  generally  accompany  the  fine  gold. 
Fissure  veins  and  other  normal  vein  types  are  also  found  at  Bendigo 
as  well  as  saddle  reefs,  and  in  many  cases  have  proved  profitable. 


[•■•/•.-■•.•  :,-/.|SANDSTONE     h->-^jg|SLATE  fcY^'J  QUARTZ 

Fig.  129.     False  Saddle  Reef,  Bkkdigo  (Rickard). 


The  most  productive  have  been  the  networks  of  veins  that  are 
locally  known  as  "  makes  of  spurs  "  or  "spur formations."  Monchi- 
quitea  dykes  traverse  the  country. 

Lindgren6  describes  the  occurrence  of  albite  in  the  veins  of 
Bendigo.  It  occurs  both  intergrown  with  the  quartz  and  also 
as  well-developed  prismatic  crystals,  projecting  from  the  walls 
of  the  vughs  in  the  quartz.  Later  crystals  of  calcite  sit  on  the  quartz 
and  albite,  and  pyrite  on  all  three.  Similar  occurrences  of  albite 
are  found  in  the  Mother  Lode  region  and  in  the  Alaska-Treadwell 
mines,  and  also  at  the  Morro  Velho  mine  of  the  St.  John  del  Bey 
Company,  Minas  Geraes,  Brazil. 


a  "  Limburgite  "  of  Howitt,  Rep.  Dep.  Mines,  Victoria,  1893. 
b  Econ.  Geol.,  I,  1906,  p.  163. 
Z 


370 


AUSTRALASIA. 


The  nearest  exposed  acidic  igneous  rocks  are  the  granodiorites 
that  lie  some  7  miles  to  the  south  of  Bendigo." 

Maryborough. — Maryborough,  south-west  of  Bendigo,  is  a 
typical  Victorian  alluvial  camp.     Its  reefs  are  also  important,  and 


Ws"  Below  Sill 


t80Y Below  SUl 


530'8"Below  801, 


S99'8"Bdow  SUl 


69V  f  Below  SUl; 


19^  Below  SUl 


893'?  Below  SUl 


399  3' Below  SUl 


?'l'Bdow  SUl 


993'9' Below  SUl 


Fig.  130.    Cross-section  through  Portion  of  Lazarus  Mine  on  the  New  Chum  Line 

of  Reef,  Bendigo  (Dunn). 

a  For  detailed  descriptions  of  Bendigo  the  following  maybe  consulted:  Richard, 
Trans.  Amer.  Inst.  M.E.,  XX,  p.  463;  XXI,  p.  686;  XXII,  p.  289;  Don.,  lb. 
XXVII,  1898,  p.  566  ;    Dunn,  Rep.  Dept.  Mines,  Victoria,  1893. 


VICTORIA.  371 

in  the  early  days  of  the  field  gave  enormous  returns  from  short 
outcrop  shoots. 

Tarnagulla,  the  scene  of  the  Poseidon  rush  of  1906  and  of  its 
nuggets,  carried  the  famous  Poverty  reef,  25^  feet  of  which  along 
the  strike  yielded  a  ton  of  gold.  The  reef  was  here  some  20  feet 
thick  for  a  depth  of  60  feet,  and  often  reached  tenors  of  50  ounces 
per  ton.  The  Poverty  reef  is  believed  to  have  yielded  gold  of  a 
total  value  of  at  least  £1,340,000.  It  was  in  these  and  in  the 
neighbouring  Kingower,  Moliagul,  and  Dunolly  diggings  that  the 
largest  Victorian  nuggets  were  found. 

Avoca,  St.  Arnaud,  and  Amherst  in  the  Maryborough  division 
are  placer  camps  of  minor  importance.  In  the  Castlemaine  division, 
south  of  Bendigo,  the  principal  field  is  Maldon  (Tarrangower). 
The  rocks  are  Ordovician  schists  and  quartzites  intruded  by  granitic 
and  basic  intrusions,  the  latter  (limburgite)  having  no  appreciable 
effect  on  the  primary  ore-deposition.  The  granitic  intrusions, 
on  the  other  hand,  are  of  importance,  since  auriferous  reefs  occur 
on  each  wall  of  a  granite  dyke.  The  granite  is  mainly  felspar  and 
quartz  with  subordinate  mica.  The  principal  mine  is  the  South 
German.  Its  reef  is  some  10  feet  in  width  and  is  highly  pyritous, 
containing  pyrite,  arsenopyrite,  chalcopyrite,  and  stibnite.  The 
gold  is  very  fine.  Maldonite,  or  bismuth-gold,  has  been  found 
here. 

The  Castlemaine  field  is  described  by  Baragwanath.fl  It 
lies  22  miles  south  of  Bendigo.  The  discovery  of  gold  was  made 
in  1851,  the  outcrop  stone  proving  very  rich.  The  rocks  of  the 
district  are  Lower  Ordovician,  the  horizon  being  determined  by 
the  numerous  graptolite  remains. b  The  rocks  vary  in  thickness 
from  fine-grained  shales  to  grits.  They  are  intruded  by  granodiorite 
and  are  metamorphosed  for  a  distance  of  some  70  feet,  from  the 
contact.  For  a  further  distance  of  440  yards  from  the  granite, 
intrusive  veinlets  or  apophyses  intersect  the  strata  in  various 
directions.  The  most  noticeable  feature  in  the  Ordovician  strata 
is  the  rapid  succession  of  meridional  anticlinal  and  synclinal  folds 
across  the  field.  The  quartz  occurrences,  as  on  many  Victorian 
Ordovician  fields,  are  to  be  grouped  as  follows  :  — 

(a)  Fissure  reefs,  occupying  and  completely  filling  well-defined 

fissures. 

(b)  Saddle  reefs,  as  at  Bendigo. 

(c)  Fault  reefs,  irregularly  deposited  along  fault  planes. 

(d)  "  Spurs,"  deposited  in  irregular  crevices  in  the  strata. 

a  Mem.  Geo!.  Surv.  Victoria,  No.  2,  1903, 
b  Hall,  Geol.  Mag.,  VI,  1899,  p.  438. 


372 


AUSTRALASIA. 


* 

<§ 


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o 

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O 


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a 

fa 

a 
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H 


a: 

<: 
o 

fa 

o 

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o 


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«2 


Plalc   XIII. 


Anticlinal  Fold.  Nimbod   Line,  Castlemaim:. 
(Geological  Survey  of  Victoria.) 


ARLTINGA    (ioLDFIELD.    MacDONNELL    RANGES,    CENTRAL    AUSTRALIA. 


VICTORIA.  373 

Although  the  limburgite  dykes  are  Tertiary  and  the  majority 
of  the  quartz  reefs  are  much  older  there  are,  nevertheless,  important 
instances  of  payable  quartz  having  been  deposited  since  the  basic 
Tertiary  intrusions.  Yields  as  high  as  30  ounces  per  ton  were 
obtained  in  quartz-veins  in  a  dyke  of  this  nature/'  Where  the 
dykes  intersect  auriferous  veins  they  do  not,  however,  appear  to 
cause  any  perceptible  enrichment. 

Though  gold  generally  occurs  in  quartz  at  Castlemaine  it  may 
also  be  found  in  clean  slate  and  in  sandstone,  usually  occurring 
as  shots  or  "  nuggets,"  the  latter  weighing  as  much  as  3  or  4  ounces. 
Associated  with  the  gold  are  small  quantities  of  pyrite,  arsenopyrite, 
blende,  and  galena. 

Ararat. — The  Ararat  division  lies  towards  the  western  desert 
region  of  the  State  and  on  the  western  end  of  the  main  Victorian 
dividing  range.  The  Ordovician  rocks  are  folded  meridionally 
as  elsewhere  in  Victoria  and  are  intruded  by  granitic  rocks,  some 
of  which  contain  gold-quartz  veins  that  were  worked  at  a  profit 
until  the  veins  passed  in  depth  (200  feet)  into  undecomposed  granite. 

The  principal  field  in  the  Ararat  division  is  Stawell,  where 
are  situated  some  of  the  deepest  workings  in  Victoria.  The 
Magdala-cum-Moonlight  and  Oriental  mines  are  the  most 
prominent.  Their  general  geological  characters  resemble  those  of 
the  eastern  fields. 

Alluvial.— The  alluvial  deposits  of  Victoria  are  divided, 
without,  of  course,  any  very  sharp  divisional  line,  into  the  shallow 
deposits  hi  the  course  of  the  present  water-channels,  and  the  so-called 
"  deep  leads  "  that  form  the  beds  of  ancient  rivers,  and  that  have 
since  been  covered  by  accumulations  of  drift  or  by  volcanic  lava- 
flows. 

The  gold  of  the  shallow  placer  deposits  of  Victoria  was  nearly 
all  exhausted  within  the  first  20  years  of  gold-digging.  Never- 
theless, from  time  to  time,  small  areas  that  have  escaped  the 
shovel  and  pan  of  the  older  generation  of  diggers  are  brought 
to  light.  The  chief  of  these  in  recent  years  has  been  the  Poseidon, 
aptly  named,  though  certainly  so  by  chance.6  It  is  situated  near 
Tarnagulla,  a  famous  camp  in  the  'fifties.  A  small  "  rush  ': 
to  this  field  took  place  towards  the  end  of  1906,  and  numerous 
nuggets  were  unearthed.  The  largest  was  found  on  December 
18th,  1906,  and  weighed  953  ounces  gross  (703  ounces  fine)  and  was 
sold  for  £2,878.  16s.  6d.    Other  nuggets  of  675,  502,  and  387  ounces 

a  Baragwanath,   loc.    cit.,   p.    14. 

"  Poseidon  was  the  grandfather  of  Argo,  the  leader  of  the  expedition  to  Colchis 
in   search  of  the   Golden  Fleece. 


374 


AUSTRALASIA. 


respectively  have  since  been  found,  and  within  a  distance  of  84  feet 
no  less  than  3,000  ounces  gold,  all  in  large  nuggets,  were  obtained. 
All  lay  in  the  soil  and  clay  and  within  a  foot  of  the  surface. 


.  Nil  N?2 


N93 


OrdOi/iciar)\  -/A 
Silurian     J  0. 

Glacial 

Basalt 
Covering 

Deep  Leads 

Belts  of    J  sf 


MILES. 


Fig.  132.     The  Loddon,  Avoca,  and  Ballarat  Deep  Leads  ( Wilkinson). 

Next,  perhaps,  to  those  of  California,  the  alluvial  deposits  of 
Australia  have  been  the  most  productive  known.  The  richer 
surface  deposits  that  in  both  cases  aroused  the  wonder  of  the 
civilised  world  have  long  been  exhausted,  and  the  working  of  the 
deep  leads  now  requires  stringent  economy  in  mining  and  manage- 


VICTORIA.  375 

ment,  for  it  is  necessary  in  most  cases  to  follow  the  buried  channels 
beneath  great  depths  of  later  alluvium,  or  of  alluvium  and  basaltic 
lava-flows.ft 

The  oldest  rocks  forming  the  bedrock  of  the  gravels  are  Ordovician 
and  Silurian  shales  and  sandstones,  in  places  intruded  by  granodiorite 
and  granite.  The  Victorian  area  has  for  long  been  a  land  surface 
in  which  deep  valleys  existed  at  least  as  early  as  Middle  Pliocene 
times  and  possibly  earlier  still.  In  later  times,  owing  to  the  regional 
depression  and  the  lessening  of  the  grade  of  the  rivers  due  to 
tilting  accompanying  secular  movements,  the  older  gravels  were 
covered  by  silts  and  clays.  Many  of  the  Tertiary  valleys  were 
filled  and  their  direction  hidden  by  great  basaltic  lava-flows  that 
range  in  thickness  up  to  400  feet.  It  appears  that  there  were  two 
widely-separated  periods  of  basaltic  eruption,  and  the  basaltic 
flows  that  fill  many  of  the  buried  valleys  of  Gippsland  are  believed 
to  be  older  than  those  of  Western  Victoria.  There  also  appear  to 
have  been  three  or  four  periods  of  temporary  cessation  of  volcanic 
activity,  when  sedimentation  was  resumed,  since  there  are,  between 
the  flows,  bands  of  alluvium  of  varying  thickness. 

The  auriferous  zones  within  the  Ordovician  rocks  of  Victoria 
are  disposed  meridionally,  and  "  deep  leads "  directly  derived 
from  the  denudation  of  these  zones  are  naturally  richer  than  those 
whose  channels  ran  along  the  broader  intermediate  barren  zones. 
Within  the  zones  themselves  there  are  also  areas  of  special  enrich- 
ment that  have  formed  by  their  denudation  the  most  notable  placer 
fields  of  the  State.  Where  tributary  "  leads  "  cross  the  belts  of 
enrichment  they  also  are  notably  more  productive.  Wilkinson, 
to  whom  we  owe  the  most  recent  and  one  of  the  best  descriptions 
of  these  interesting  deposits,  concludes6  that  it  is  only  where  the 
fine  gold  transported  from  a  distance  has  been  supplemented  by 
the  local  gold  derived  from  gold-quartz  veins  lying  in  areas  or 
belts  of  enrichment,  that  the  deep  leads  may  be  profitaoly  worked. 
Very  often  the  enrichment  due  to  local  gold-quartz  veins  is,  in 
leads  of  low  gradient,  confined  to  within  a  few  hundred  feet  down- 
stream from  the  vein.  Several  of  the  deep  leads  have  been  traced 
for  a  distance  of  50  to  60  miles.  The  auriferous  gravel  or  "  wash  " 
as  a  rule  consists  of  sand  with  water-worn  quartz  pebbles  of  an 
average  diameter  of  perhaps  3  inches,  but  which  may  nevertheless 
reach  3  feet  in  diameter.  The  thickness  of  the  wash  varies 
considerably  with  the  character  of  the  bedrock  and  with  the 
original  grade  of  the  old  river  channel.  Tts  average  thickness  is 
3  feet,  but  it  may  reach  12  feet. 

a  Lindgren,  Mining  Mag.,  II,  1905,  p.  33. 

6  Wilkinson,  H.  L.,  Trans.  Inst.  Min.  and  Met.,  1907,  p.  9. 


376 


AUSTRALASIA. 


From  various  causes,  of  which  a  normal  decrease  in  the  velocity 
of  many  streams  below  their  junction  with  other  streams  is  the 
principal,  the  richness  of  deep-lead  gravels  is  generally  greater 
below  the  junction  of  the  old  streams  than  in  either  of  the  tributary 
channels.  The  Ordovician  slates  are  noticeably  more  effective 
in  retaining  gold  than  the  sandstones  of  the  same  series,  since  the 
latter  wear  smooth  and  the  former  to  natural  riffles. 

The  principal  deep-lead  systems  of  Victoria  are  the  Stawell, 
Avoca,  Loddon,  Campaspe,  Goulburn,  Ovens,  and  Murray,  all  in 
old  channels  in  which  the  streams  flowed  north  towards  the  site 
of  the  present  valley  of  the  Murray,  and  probably  to  a  then  existing 
similar  river  system,  or  possibly  to  an  inland  sea.  The  Pitfield, 
Ballarat,  and  Dargo  leads  are  the  chief  of  those  lying  in  the  old 
channels  possessing  a  southward  course.  Most  of  the  gold  lies 
either  on  bed-rock  or  in  some  2  or  3  feet  of  gravel  above  bed-rock. 
This  portion  alone  is  worth  working.  The  amount  extracted  is  there- 


LONCITUDINAL   SECTION  ALONG  THE  BALLARAT  a  BERRY-LODDON  LEADS. 


V  "'Its      X 


CROSS  SECTION  THROUGH  THE  DUKE  &  LODDON  LEADS. 


I        | 

soo    $ 

...;..     .     i i .1.  i  .J.-™  § 


//     H/ies       10 


Figs.  133  and  134.     Sections  of  Victorian  Deep  Leads  {Wilkinson). 


fore  measured  in  Victoria  by  a  superficial  unit,  the  square  fathom. 
The  present  gradients  of  the  principal  leads  are  low  and  range 
from  10  to  40  feet  per  mile.  In  some  places  indeed,  the  gradients 
are  reversed,  and  the  coarse  gravels  lying  on  bed-rock  in 
longitudinally  horizontal  channels  show  clearly  that  tilting 
has  occurred  since  the  deposition  of  these  gravels.  By  far 
the  richest  and  most  extensive  ancient  placer  channel  is 
the  great  Loddon  Lead  system  with  its  various  tributaries, 
of  which  the  Madam  Berry  Lead,  near  Creswick,  has  been  the 
richest.  In  the  Madam  Berry  mine,  on  that  lead,  an  area  of  wash 
5,800  feet  long  and  450  feet  wide  yielded  more  than  £1,500,000. 
The  extraordinary  local  richness  of  this  lead  is  due  to  the  enriching 
effect  of  a  series  of  quartz-reefs,  each  in  itself  perhaps  unpayable, 
over  which  the  old  stream  has  flowed.  Except  in  Gippsland  and 
near  Daylesford  the  leads  are  rarely  sufficiently  elevated  to  be 
worked  level  free.     The  most  important  deep  lead  in  the  north- 


VICTORIA. 


377 


eastern  portion  of  the  State  is  the  Chiltern-Rutherglen,  which  has 
been  worked  from  beneath  the  Chiltern  Hills  for  25  miles  towards 
the  Murray  River.  It  is  probably  continued  beneath  that  river 
into  New  South  Wales. 

According  to  Wilkinson/  the  factors  determining  the  quantity 
of  alluvial  gold  in  the  wash  are  : — 

(1)  The  disposition  of  the  auriferous  zones  of  Victoria. 

(2)  The  position  of  the  belts  of  enrichment  on  the  various 
auriferous  zones. 

(3)  The  longitudinal  gradient  of  the  lead  bed. 

(4)  The  cross  profile  of  the  lead  channel. 

(5)  The  variations  in  width  of  wash  and  consequent  variations 
in  value. 

(6)  The  junction  of  two  leads. 

(7)  The  capacity  of  the  bed-rocks  for  arresting  and  retaining 
particles  of  gold. 

The  deep  leads  are  worked  by  sinking  shafts  to  bed-rock  in 
the  deepest  part  of  the  channel,  and  driving  levels  within  the  bed- 
rock from  the  bottom  of  the  shafts.  From  the  levels  the  overlying 
gravels  are  reached  by  a  series  of  rises  or  raises. 

Numerous  dredging  companies  have  been  formed  to  work  the 
shallower  placers.  Some  of  these,  especially  in  the  neighbourhood 
of  Beechworth,  have  been  very  successful.  The  largest  (the 
Eldorado,  Beechworth)  obtained  in  1907  gold  to  the  amount  of 
3,492  ounces,  together  with  39  tons  tin-ore. 

The  total  quantity  of  gravel  treated  in  Victoria  in  1906  by 
bucket-dredging,  pump-sluicing,  and  jet-elevating,  was  17,307,277 
cubic  yards,  which  yielded  85,271  ounces  gold,  or  an  average  yield 
of  2-36  grains  per  cubic  yard.  Of  the  value  recovered  £45,629 
was  paid  in  dividends. 

During  the  present  century  gold  to  the  following  amount  and 
value  has  been  obtained  from  Victoria  :  — 


Year. 

Crude  Ounces. 

Value. 

1901 

789.562 

£3,102,753 

1902 

777,738 

3,062,028 

1903 

822,424 

3,259,482 

1904 

821,017 

3,252,045 

1905 

810,050 

3,173,744 

1906 

834,775 

3,280,478 

1907 

695,576* 

2,981,855 

*  Fine  ounces,  returns  of  crude  ounces  not  being  available. 


a  Loc.   cit.,  p.  7. 


378  AUSTRALASIA. 

The  total  yield  of  Victoria  from  1851  to  1907  inclusive  has 
been   65,792,063  fine  ounces  worth  £279,498,833. 


TASMANIA. 


The  geology  of  the  older  rocks  of  Tasmania  presents  no  essential 
difference  from  that  of  similar  strata  in  Victoria,  save  that  the 
Archaean  and  pre-Cambrian  rocks  are  developed  in  Tasmania  to  a 
relatively  much  greater  extent  than  on  the  mainland.  These 
fundamental  rocks  are  highly  crystalline  quartzites  and  hornblende- 
mica-schists,  that  form  an  extensive  belt  down  the  west  coast  of  the 
island.  They  contain  no  auriferous  deposits  of  importance.  The 
auriferous  rocks,  par  excellence,  of  Tasmania  are,  as  in  Victoria, 
the  Ordovician  sedimentary  rocks.  Through  these  strata  is 
intrusive  the  granitic  core  of  the  Australian  Cordillera,"  which 
is  certainly  younger  than  Silurian,  and  is  possibly,  though  the 
evidence  on  this  point  is  not  conclusive,  younger  even  than  Permo- 
Carboniferous.  At  the  Lisle  and  Golconda  fields  auriferous  veins 
traverse  the  granite.  The  further  evidence  available  goes  to  show 
that  the  period  of  auriferous  ore-deposition  was  certainly  not 
subsequent  to  the  Permo-Carboniferous,  and  that  there  is  therefore 
no  possible  genetic  connection  between  the  ore-deposits  and  the  great 
Mesozoic  diabase  eruptions  of  Tasmania.  According  to  Waller b 
the  auriferous  copper-schists  of  Mount  Lyell  are  undoubtedly  due 
to  the  intrusion  of  the  granite  into  Lower  Silurian  rocks.  It  will 
thus  be  apparent  that  the  general  relations  of  Tasmanian  auriferous 
occurrences  resemble  very  closely  those  of  the  already-described 
goldfields  of  the  Eastern  Cordilleras  of  Australia. 

The  principal  goldfields  of  Tasmania  are  Beaconsfield,  Lefroy, 
Mathinna,  and  Mount  Lyell.  The  first  three  are  closely  related 
geologically  and  lie  in  the  not  greatly  altered  Lower  Silurian  or 
Ordovician  sedimentary  rocks  of  the  north-east  of  the  island. 

The  first  payable  gold  was  found  in  Tasmania  in  1852,  at  the 
Nook,  near  Fingal,  where  the  first  gold-quartz  mine  was  also  opened 
up  some  seven  years  later.  The  entire  production  of  gold  prior  to  1867 
was  only  843  ounces,  while  that  from  1866  to  1907  has  been  about 

a  Twelvetrees,  Trans.    Aust.   Inst.    M.E.,    V,    1898,    p.    105;     Montgomery,    lb. 
Ill,  1895,  p.  204. 

b  Rep.  Aust.  Ass.  Adv.  Sci.,  1904,  X,  p.  629. 


TASMANIA. 


379 


1,700,000  crude  ounces,  worth  £6,538,252.    The  more  recent  returns 
are  as  follows  :  — 


Year. 

Fine  Ounces. 

Value,  Sterling. 

1901 

69,491 

£295,176 

1902 

70,996 

301,573 

1903 

59,891 

254,403 

1904 

65,921 

280,015 

1905 

73,541 

312,380 

1906 

60,023 

254,963 

1907 

65,354 

277,607 

Beaconsfield. — The  Beaconsfield  goldfield  contains  a  single 
mine — the  Tasmania — which  is  situated  on  the  west  side  of  the 
Tamar  river,  and  about  three  miles  from  deep  water.  The  reef  was 
found  in  1877  as  a  gossan,  from  1|  to  4  feet  in  width,  outcropping 
at  the  crest  of  a  long  ridge  (Cabbage  Tree  Hill)  that  overlooks  the 
low-lying  ground  of  the  West  Arm  branch  of  the  Tamar  river. 

The  Lower  Silurian  sedimentary  series  in  which  the  reef  occurs 
is  made  up  of  sandstones,  grits,  conglomerates,  shales,  and  lime- 
stones, conformably  bedded,  striking  north-west  and  south-east 
and  dipping  north-east  at  65°.  The  lower  slopes  of  the  ancient 
ridge  on  which  the  vein  outcrops,  are  now  hidden  by  the  alluvial 
deposits  of  the  West  Arm,  a  drowned  Tertiary  valley.  The  old 
deep  gravels  of  this  valley  carried  rich  alluvial  gold  where  they 
were  deposited  immediately  below  the  Tasmania  vein-outcrop. 

The  Tasmania  reef  strikes  about  north-east  and  south-west, 
almost  indeed  at  right  angles  to  the  strike  of  the  strata,  and  under- 
lies to  the  south-east  at  1  in  2|  to  1  in  3.  It  obviously  fills  a  fault- 
fissure,  since  the  beds  are  vertically  displaced  on  either  side  of  the 
course  of  the  vein.  Fossils  of  a  species  of  Orthis  were  obtained  in 
the  workings,  indicating  the  general  Lower  Silurian  age  of  the 
country.  The  reef  is  from  2  to  25  feet  in  width  and  averages  perhaps 
from  6  to  8  feet.  At  the  present  time  its  tenor  ranges  from  9  dwts. 
to  63  ounces  per  ton.  The  average  tenor,  as  deduced  from  the  ore 
crushed,  has  been  25  dwts.  per  ton.  "  Horses  "  are  of  frequent 
occurrence  in  the  lode.  The  oxidised  zone  descended  to  a  depth 
of  400  feet.  In  the  lower  levels  the  gold  is  associated  with  pyrite, 
chalcopyrite,  and  blende.  Siderite  is  common.  Shoots  in  this  mine 
are  not  particularly  well  marked,  and,  despite  the  former  belief 
to  the  contrary,  the  varying  nature  of  the  country  walls  has 
apparently  not  exercised  a  great  deal  of  effect  on  local  vein 
enrichment. a  The  Tasmania  pumping  plant  is  probably  the  most 
powerful  employed  at  any  gold  mine  ;    its  use  is  necessitated  by 


a  Montgomery,  Rep.  Pari.  Papers,  Tasmania,  XXIV,  1891. 


380 


AUSTRALASIA. 


the  fact  that  the  mine,  owing  to  the  dip  and  nature  of  the  strata 
and  the  disposition  of  the  watercourses,  drains  the  country  over  a 
wide  area.  At  times  the  pumps  have  had  to  deal  Avith  quantities 
of  8,100,000  gallons  of  water  per  day.  In  June,  1906,  the  subsidence 
of  a  limestone  cave,  1J  miles  from  the  workings,  led  to  the  flooding 
of  the  lower  levels.  The  Tasmania  shafts  had  attained  in  1908  a 
depth  of  1,250  feet.  The  reef  above  the  715-foot  level  had  then 
been  completely  blocked  out. 


•BE  AC  0  N  S  FTE  LD 


-'^Cabb 


I     Mile 


Cabbage  Tree 
aHill 


Beaconsfield 


Figs.  135  asd  136.      Plan  and  Section  of  Country  in  the  neighbourhood  of  the   Tasmania 

Lode,  Beaconsfield  {Montgomery). 
1.  Blue  slate.     2.  Black  shining  slate.     3.  Soft  slate.     4.  Light  and  dark  grits  and  conglomerates. 
o.|Black    sandstone.       6.  White   sandstone.     7.  Dark    blue    sandstone.     8.  Light    sandstones.     9. 
Limestone.     10.  Slate. 


The  Tasmania  reef  is  almost  anomalous  among  gold-quartz 
veins,  inasmuch  as  it  shows  no  dependence,  direct  or  indirect,  on 
intrusive  igneous  rocks.  The  nearest  known  igneous  rocks  are  the 
peculiar  white  binary  quartz-felspar  granite  and  the  biotite-granite 
of  Anderson's  Creek,  some  three  miles  west  of  the  mines.  Both 
granites  are  decidedly  aplitic  in  appearance. a 


a  Twelvetrees,  Rep.  Aust.  Assoc.  Adv.  Sci.,  X,   1904,  p.  211. 


TASMANIA.  381 

To  the  end  of  1907  the  Tasmania  mine  had  produced  695,158 
ounces  gold  from  686,735  tons  quartz,  and  had  distributed  to  its 
shareholders  to  the  end  of  the  year  1905,  £772,672  in  dividends. 
Since  that  date  the  profits  made  on  working  have  been  absorbed  by 
large  capital  expenditure. 

Lcfroy. — The  Lefroy  district  is  seven  miles  east  of  the  Tamar, 
and  28  miles  north  of  Launceston.  Its  country  is  slate  and  sand- 
stone of  probable  Lower  Silurian  age.  The  strata  have  been  greatly 
folded  and  dip  irregularly.  In  the  vicinity  of  the  veins,  however, 
the  dip  is  only  from  15°  to  30°. a  The  general  strike  of  the  strata, 
as  at  Beaconsfield,  on  the  other  side  of  the  Tamar,  is  north-west 
and  south-east.  Unlike  Beaconsfield,  where  there  is  no  visible 
occurrence  of  igneous  rock  in  the  immediate  vicinity  of  the  mine, 
Lefroy  shows  granite  in  the  south-west  of  the  field. 

Slow  subsidence  of  north-eastern  Tasmania  in  Tertiary  times 
has  filled  with  alluvial  deposits  the  old  valleys  at  Lefroy,  as  at 
Beaconsfield.  A  little  alluvial  gold  has  from  time  to  time  been 
found  in  the  deep  leads  so  formed. 

The  auriferous  veins  lie  in  a  long  lenticular  area  of  soft 
country,  that  strikes  north-west  with  the  Lower  Silurian  strata. 
The  auriferous  lodes  strike  east  and  west  and,  as  is  general  in  a 
schistose  or  slaty  country,  are  disposed  en  echelon.  The  lodes  occupy 
fault-fissures  in  the  country,  and  movements  appear  to  have  taken 
place  in  the  fissure  subsequent  to  the  first  deposition  of  auriferous 
quartz,  brecciating  the  walls  and  the  already  deposited  quartz. 
The  lode-channels  are  often  50  to  100  feet  wide,  with  intervening, 
and  sometimes  brecciated  "  horses."  The  gangue  is  quartz,  and 
the  gold  is  associated  with  pyrite,  chalcopyrite,  arsenopyrite, 
and  stibnite,  the  last  being  considered  a  particularly  favourable 
indicator  for  gold,  especially  in  the  mines  closest  to  the  granite. 
The  gold  is  distributed  in  more  or  less  regular  shoots.  The  rich 
shoots  of  the  Lefroy  field  have  invariably  pinched  out  at  350  to 
400  feet,  and  although  gold  has  been  obtained  at  greater  depths 
of  800  and  1,100  feet,  the  quartz  has  been  low  grade.  The  general 
course  of  the  payable  reefs  is  N.  75°  E.,  with  an  underlay  south 
from  3°  to  46°.6 

Mathinna. — Mathinnac  lies  some  40  miles  east  of  Launceston 
and  1,000  feet  above  sea-level.  The  auriferous  series  is  clay, 
slate,  graphitic  slate,  quartzite,  sandstone,  and  argillaceous  sand- 
stone.   The  main-fissure  lines  in  the  Golden  Gate  zone  strike  nearly 

a  Montgomery,  Rep.  Govt.  Geol.  Tas.,   1897,  p.   111. 

b  Jolly,  Trans.  Aust.  Inst.  M.E.,  IV,  1897,  p.  132  ;  Sandeman,  Trans.  N.  Eng.  Inst. 
M.E.,  XLIX,  1900,  p.  28. 

c  Twelvetrees,  Rep.  Mines  Dep.,  Tasmania,  1906,  p.  1. 


382 


AUSTRALASIA. 


NEW  GOLDEN  CATE  REEFS 

Cross  section    lookingNorth 


I 


DFTS* 


north  and  south.  Twelvetrees  notes  that  in  the  New  Golden  Gate 
mine,  a  reef  is  auriferous  when  its  course  is  a  little  east  of  north, 
but  barren  when  to  the  west  of  north.  An  anticlinal  axis  runs  north- 
north-west  and  south-south-east  through  the  field,  and  is  believed 
to  bear  an  important  relation  to  the  lode  fissures,  which  suggest 
to  a  certain  degree  saddle-reef  development,  though  the  legs 
certainly  do  not  dip  exactly  with  the  country  on  both  sides  of 

the  crest.  The  vein-matrix  is  quartz, 
with  pyrite  and  arsenopyrite.  A  connec- 
tion is  traced  by  Twelvetrees  with  the 
granites  that  are  exposed  10  miles  to  the 
north-east  of  Mathinna,  where  the  reefs 
in  the  granite  carry  gold  :  '  The  few 
observations  that  I  have  been  able  to 
make  in  various  parts  of  the  State 
(Tasmania)  would  tend  to  support  the 
supposition  that  the  origin  of  our  gold- 
quartz  is  mainly  granitic,  and  that  the 
formation  of  the  reef  is  essentially  asso- 
ciated with  tectonic  disturbance  of  the 
stratified  rocks."  The  values  on  the 
Mathinna  field  are  mainly  in  the 
sulphides,  samples  of  which  from  the 
1,600-foot  level  of  the  New  Golden  Gate 
have  yielded  as  much  as  80  ounces  of  gold 
per  ton.  The  sulphides  are  pyrite,  arseno- 
pyrite, galena,  chalcopyrite,  and  blende. 
Galena  and  blende  are  locally  considered 
the  most  favourable  indicators.  Blende 
is,  however,  absent  from  the  lower  levels. 
Secondary  outcrop  enrichment  of  the 
normal  type  has  taken  place  on  this  field, 
much  of  the  outcrop  stone  yielding  from 
3  to  11  ounces  per  ton.  The  deepest 
shaft  at  Mathinna  in  1908  had  reached  1,900  feet.  At  this 
depth  quartz  assaying  24  dwts.  per  ton  was  met  with.  The  gold 
in  the  upper  levels  was  always  of  greater  fineness  than  that  from 
depth  ;  for  example,  the  alluvial  gold  was  953-5  fine  ;  from  the 
surface  to  the  360-foot  level,  the  vein-gold  was  955  to  900-5  fine  ; 
and  at  the  1,100  and  1,200  foot  levels  only  925-5  to  850  fine. 

The  auriferous  quartz-veins  of  Mathinna  do  not  occur,  as  do 
true  saddle  reefs,  in  the  crests  and  troughs  of  the  folds.  They  are 
confined,  as  at  Lefroy,  to  broad  zones  of  fissured  country.  The 
Golden  Gate  zone  is  600  to  1,000  feet  wide.  The  New  Golden  Gate 
mine,  Mathinna,  to  the  end  of  1906  had  produced  222,755  ounces 


-fn^Hjmrn^m 


Fig.  137.  Section  through 
New  Golden  Gate  Mike,  Math- 
lvxa  (Twelvetrees). 


TASMANIA. 


383 


gold  from  267,140  tons  quartz  worth  £847,075,  and  had  paid  in 
dividends  £355,200  on  a  share  capital  of  £9,600.  The  main  shaft 
is  sunk  to  a  depth  of  1,620  feet. 

Mount  Lyell.—  Mount  Lyell  is  one  of  the  famous  copper 
mines  of  the  world.  The  district  was  discovered  to  be  payably 
auriferous  in  1883,  when  a  rich  quartz  outcrop  was  found,  from 
which  a  hundredweight  of  stone  yielded  to  the  discoverer  £831 
gold.    This  was,  however,  not  the  outcrop  of  the  Mount  Lyell  mine 


\l       o  °  „  °      °  °         o°°°oo0oo 

vyiVo  Vo°3°°  o-°0\v  •  •  ° 


o      o     o     o 


°  #°      <?  —  -.     O  n  °       O       „ 


O       O      o        o 


o    °    °    o-s-^^o    o  .  o    o      o 


o      o 

c 

0 


_ Faults 


0°  S«.o\  °      d 
\o     °    °    o   o^o  °0 

_-'  „    °    n    O      t,      o    ° 


Fig.  138.     Sketch  Map  of  Geology  of  Mount  Lyell  (Gregory). 

1.  Queen  River  porphyry.     2.  Mount   Lyell   schists.     3.  Devonian   conglomerates. 
4.  Glacial  deposits.     5.  Alluvium. 

itself,  since  that  mine  was  not  discovered  until  1886,  and  then 
the  alluvial  shoadings  alone  were  worked.  In  1893,  the  present 
Mount  Lyell  Company  was  formed,  the  smelters  commencing 
work  in  1896. 

The  rocks  of  Mount  Lyell  are  considered  by  Gregory a  to  be 
margarodite-schists   and   chlorite-schists   derived  from  porphyrite 


a  Trans.  Aust.  Inst.  M.E.,  1905,  X,  p.   07. 


384  AUSTRALASIA. 

or  porphyrite-tuffs  ;  these  are  associated  with  schistose  quartz- 
porphyries  and  schistose  volcanic  tuffs,  of  pre-Silurian  (?)  age. 
Diabase-porphyrites  and  diabase  dykes  are  intrusive  into  the  series. 
The  series  is  apparently  associated  with  undoubted  Silurian  sand- 
stones and  limestones  and  with  conglomerates  of  probable  Devonian 
age.  The  rocks  of  the  field  are  greatly  faulted.  The  ore-deposits 
comprise  mineralised  bands  of  schist  (fahlbands)  and  lens-shaped 
masses  of  very  pure  sulphide  ores.  The  minerals  are  chiefly  pyrite 
and  fahlore,  with  chalcopyrite  and  bornite.  The  first  two  indicate 
high  grade,  but  are  erratic  in  distribution.  A  range  of  assays 
yielded  the  following  averages  :  — 

(1)  (2) 

Copper    .  .  .  .  .  .        1-54  .  .  6-96  per  cent. 

Silver      ..  ..  ..  -36  ..  -19  ozs.  per  ton. 

Gold        -008  . .  -019  „ 

The  masses  of  sulphide  ore  furnish  the  bulk  of  the  ore-deposit. 
The  footwall  side  of  the  great  ore-body  is  the  richer  in  copper, 
silver,  and  gold.  Bornite  and  fahlore  enrichments  occur  within 
the  body,  and  assay  Cu  3-65  per  cent.,  Ag  2-07  ounces,  Au  0  02 
ounces  per  ton.a  Some  secondary  outcrop  enrichment  has  taken 
place.  This  is  a  relative  and  not  an  actual  enrichment,  as  is  evident 
from  the  poverty  of  the  "  Ironstone  Blow  "  in  copper  and  silver. 
The  average  tenor  of  the  ore  being  treated  in  1907  was  2-18  per 
cent,  copper,  1  -65  ounces  silver,  and  94  dwts.  gold  per  ton.  About 
400,000  tons  ore  are  being  treated  annually  for  some  20,000  ounces 
gold.  From  August,  1903,  to  March,  1907,  about  1,500,000  tons 
ore  were  mined  for  some  30,000  tons  copper,  2,711,516  ounces 
silver,  and  82,481  ounces  gold. 

Placer  gold  has  never  been  of  importance  in  Tasmania.  *  The 
largest  nuggets  recorded  were  found  on  the  Whyte  river  in  1883 
and  weighed  243  and  143  ounces  respectively. 


SOUTH    AUSTRALIA. 

The  goldfields  of  South  Australia  proper  are  small  and  unimpor- 
tant. They  are,  with  one  exception  (Tarcoola),  contained  within 
the  Cambrian  and  pre-Cambrian  rocks  of  the  mountain  range  that 
traverses  Kangaroo  Island,  then  swings  to  the  north  through  Cape 
Jervis  and  passes  through  Mount  Lofty  to  the  east  of  Adelaide. 
Further  north  the  range  is  prolonged  to  the  north-east  towards  the 
famous  Broken  Hill  silver  fields,  but  the  older  rocks  are  here  exposed 
only  as  discontinuous  outcrops.  Both  Cambrian  and  pre-Cambrian 
strata  are  extensively  intruded  by  igneous  rocks.     The  fields  near 

"  Gregory,   loc.    cit.,    p.    1l'.">. 


SOUTH   AUSTRALIA.  385 

Adelaide  have  in  the  past  furnished  considerable  quantities  of 
alluvial  gold,  but  have  not  otherwise  been  of  importance.  For  the 
most  part  they  may  be  dismissed  with  the  mere  indication  of  their 
position.  They  occur  on  Kangaroo  Island,  and  at  Jupiter  Creek, 
Hahndorf,  Echunga,  Gumeracha,  Barossa,  and  Mount  Pleasant, 
all  from  17  to  35  miles  north  or  north-west  of  Adelaide. 

The  Echunga  field  was  one  of  the  earliest  known  in  South 
Australia,  having  been  discovered  in  1851,  consequent  on  the 
great  stimulus  given  to  prospecting  by  the  discovery  of  the  rich 
placers  of  New  South  Wales  and  Victoria  earlier  in  that  year.  The 
gold  of  Echunga  was  mainly  alluvial  and  lay  in  Older  Pliocene 
gravels  on  the  slopes  and  tops  of  the  hills,  as  also  was  the  case 
at  the  Barossa  and  at  other  fields  further  south.  Several  gold 
veins  have  been  worked  in  the  neighbourhood,  but  have  not 
proved  profitable.  At  the  Bamannah  mine,  14  miles  east-south- 
east of  Adelaide,  small  nuggets  of  gold  occur  with  native  bismuth 
in  a  quartz-vein.  The  country  of  the  vein  is  kaolinised  slate  and 
argillaceous  sandstone  of  Cambrian  age. 

Of  the  numerous  small  fields  lying  toward  the  New  South  Wales 
frontier  at  Broken  Hill,  the  Teetulpa,  Wadnaminga,  King's  Bluff 
(Olary),  Nillinghoo,  and  Mannahill  are  the  principal.  These  are  all 
well  served  by  the  Pietersburg — Broken  Hill  railway.  They  nearly 
all  depend  on  placer  gold,  and  their  gold-quartz  veins  are  but  little 
worked.  The  placers  of  the  Teetulpa  field,  15  miles  east  of 
Waukaringa,  were  first  worked  in  1886.  The  "wash"  was  rich, 
but  was  very  limited  in  extent.  The  largest  nugget  found  weighed 
29  ounces  15  dwts.  The  gravels  are  of  Pliocene  age.  The  total 
amount  of  placer  gold  obtained  from  this  field  is  unknown,  but  it 
is  believed  that  gold  to  the  value  of  £300,000  was  obtained/1  The 
Wadnaminga  field,  opened  two  years  after  Teetulpa,  lies  in  a  region 
of  Cambrian  mica-slate,  sandstone,  clay-slate,  and  crystalline 
dolomitic  limestone.  The  slates  and  flags  contain  large  scattered 
boulders  of  granite  and  quartzite.  The  Veins  of  Wadnaminga  are 
small,  but  carry  rich  pockets  of  gold-quartz. 

The  outlying  goldfield  of  Tarcoola  (Long.  134°  30'  E.  ;  Lat.  30° 
31'  S.)  is  some  360  miles  north-west  of  Adelaide,  and  170  miles  from 
the  nearest  railway  station  at  Coward  Springs.  The  field  lies  in  a 
sand-waste,  barren  beyond  description.  It  is  difficult  of  access  and 
its  mines  are  consequently  expensive  to  work.  The  country  is  an 
interstratified  quartzite,  sandstone,  and  siliceous  slate  overlying  a 
generally  mica-less  granitic  rock  that  is  associated  with  diorite, 
felspar-porphyry,  and  hornblende  granite.  The  sedimentary 
members  form  a  low  ridge  about  200  feet  in  height.      The  reefs 

a  Brown,  "  Handbook  of  Mining,  South  Australia,"  1901,  p.  7. 
Al 


386 


AUSTRALASIA. 


traverse  both  the  sedimentary  rocks  and  the  underlying  granite. 
Diorite  dykes  are  found  and  have  probably  exerted  some  influence 
on  ore-deposition.  The  gold  is  finely  divided  and  occurs  in  shoots/' 
The  first  alluvial  gold  was  found  in  1893,  and  in  1899  a  "rush  " 
of  minor  importance  took  place,  the  richness  of  the  vein-outcrops 
furnishing  the  inducement.  At  the  first  crushing  of  the  principal 
mine  (Tarcoola  Blocks)  384  tons  quartz  yielded  at  the  rate  of  3i 
ounces  per  ton.  From  May  16th,  1901,  to  June  30th,  1907,  this 
mine  had  crushed  26,719  tons  ore  for  a  yield  of  36,086  ounces  crude 
gold  worth  £112,355. 

The  gold  returns  of  South  Australia  and  of  the  Northern 
Territory  have  not  always  been  separated.  Their  total  combined 
yield  to  1903  inclusive  has  been  £2,573,357. 

Of  South  Australia  alone  the  following  figures  are  probably 
as  correct  an  approximation  to  the  truth  as  is  now  possible  :  — 


Year. 

Ounces. 

Value,  Sterling. 

1859-1900 

£556.631 

1901 

4,918 

16,613 

1902 

7,245 

24,878 

1903 

8,650 

28,650 

1904 

17,897 

76,025 

1905 

10,983 

45.853 

1906 

13,961 

58,453 

Northern    Territory The  Northern  Territory  has  long  been 

administered  by  South  Australia,  but  was  in  1908  being  taken 
over  by  the  Federal  Government.  Its  principal  goldfields  lie  along 
a  belt  that  stretches  for  some  200  miles  south-east  of  Port  Darwin 
along  an  exposure  of  pre-Cambrian  rocks.  The  principal  area  is 
that  of  Pine  Creek,  145  miles  from  Port  Darwin,  with  which  it  is 
connected  by  railway. 

The  basement  rocks  of  the  region  are  pre-Cambrian  schists, 
phyllites,  and  quartzites.  These  are  overlain  by  Cambrian  lime- 
stones, containing  Olenellus,  Agnostus,  and  Macrodiscus.  The 
limestones  are  succeeded  by  Ordovician  (?)  and  Permo-Carboniferous 
strata.  The  pre-Cambrian  rocks  are  extensively  intruded,  e.g.,  at 
Pine  Creek,  by  a  coarse-grained  granite.  Diorite  and  gabbro  dykes 
are  also  found  traversing  the  pre-Cambrian  members/' 

The  affinities  of  these  goldfields  are  clearly  with  those  of  the 
"Auriferous  Series"  of  Western  Australia.     The  lodes  of  the  Pine 


a  Brown,  Rec.  Mines  Dept.,  S.A.,  1902. 

6  Brown  and  Basedow,  Rep.  Govt.  Geol.  S.A.,  "Northern  Territory,"  1905,  p.  14. 


SOUTH     AUSTRALIA.  387 

Creek  district  are  rich  but  small.  Those  lying  within  the  phyllites 
and  schists  are  often  lenticular.  The  mines  are  largely  in  the  hands 
of  Chinese.  English  companies  have  spent  a  considerable  amount 
of  capital  on  the  gold  mines  of  the  territory,  but  with  unfortunate 
results.  The  outcrops  of  the  veins  of  the  Pine  Creek  region  have  at 
times  shown  considerable  enrichments.  At  the  Extended  Union 
mine,  Union  district,  30  miles  north  of  Pine  Creek,  gold  occurred 
near  the  surface  in  numerous  curved  laminated  plates  1J  inches  wide 
and  ^-inch  thick.  The  country  of  the  vein  is  crystalline  dolomite 
disposed  in  scattered  masses  in  phyllite." 

The  Arltunga  goldfield  lies  in  the  heart  of  the  central  desert 
of  Australia.  It  is  therefore  difficult  of  access,  and  naturally  presents 
insuperable  obstacles  to  cheap  and  efficient  working.  The  mines 
are  in  the  White  Range,  70  miles  north-east  of  Alice  Springs 
Telegraph  Station.  The  country  is  quartzite  and  quartzose  sand- 
stone with  occasional  dykes  of  granite  and  diorite.  The  veins  occur 
in  the  quartzite.  The  outcrop  stone  is  ferruginous  and  highly 
cellular,  indicating  abundance  of  pyrite  in  depth.  Gold  was 
discovered  in  1897,  and  to  June  30th,  1907,  there  had  been  treated 
8,780  tons  quartz  for  10,886  ounces  gold  worth  £40,524,  or  an 
average  tenor  of  £4.  12s.  per  ton. 

The  earliest  discovery  of  gold  in  the  Northern  Territory  appears 
to  have  been  made  by  a  telegraph  operator  in  1870,  but  no  influx 
of  miners  took  place  until  two  years  later.  From  1881  to  1890  the 
total  yield  was  478,840  ounces  gold  worth  £1,639,908.  The  present 
yield  is  about  20,000  ounces  annually. 


WESTERN  AUSTRALIA. 

The  State  of  Western  Australia  was  until  the  last  twenty  years 
generally  believed  to  be  devoid  of  mineral  wealth,  a  belief  that  arose 
rather  from  the  inaccessibility  of  its  interior  desert  country  than 
from  any  actual  knowledge  of  the  geology  of  the  State,  for  even  at 
the  present  day  there  are,  towards  the  South  Australian  border,  wide 
tracts  of  untraversed  country.  The  first  important  gold-discovery 
was  made  at  Kimberley  in  1882.  It  was  followed,  five  years  later, 
by  that  of  Yilgarn,  200  miles  east  of  Perth.  The  sensational  finds 
at  Coolgardie,  in  1892,  with  which  the  history  of  gold  in  Western 
Australia  may  properly  be  said  to  commence,  paved  the  way  for 
numerous  similar  discoveries  to  the  north,  east,  and  south. 

a  Basedow,   in  verb. 


388  AUSTRALASIA. 

The  gold  mines  of  central  Western  Australia  are  situated  on  a 
desert  tableland  about  1,200  to  1,400  feet  above  sea-level.  The  chief 
town  and  gold-mining  centre,  Kalgoorlie,  is  some  300  miles  east  of 
Perth.  The  auriferous  rocks  are  disposed  in  long  narrow  bands,  with 
a  general  meridional  or  north-north-westerly  strike.  But  little  is 
known  of  the  boundaries  of  the  belts,  especially  in  their  northern 
extensions,  for  natural  and  climatic  conditions  militate  greatly 
against  geological  work,  and  the  important  results  that  have  already 
been  obtained  by  the  Geological  Survey  of  Western  Australia  are 
almost  entirely  the  work  of  recent  years,  and  represent  an  amount  of 
labour  and  actual  hardship  inconceivable  to  workers  in  less  torrid 
climes. 

Of  the  areas  so  far  examined,  that  of  the  Pilbara  goldfield 
appears  to  throw  the  greatest  light  on  the  age  and  relations  of  the 
auriferous  series.  Gneissoid  granites  are  believed  to  represent  the 
fundamental  rocks  of  the  country.  On  this  floor  are  laid  the  great 
series  of  rocks  to  which  the  general  designation,  "  greenstone  schists  ': 
has  fitly  been  applied,  the  much-abused  term,  "greenstone,"  being 
here,  as  by  Williams  and  others  in  the  Lake  Superior  region,  em- 
ployed merely  as  a  comprehensive  field  term.  The  schists  of  the 
Pilbara  district  have  not  as  yet  been  examined  microscopically,  but 
they  are  undoubtedly  in  part  identical  with  those  of  the  Mount 
Magnet,  Kalgoorlie,  and  other  fields  to  the  south.  So  far  as  they 
have  been  differentiated,  they  have  been  found  to  consist  in  the 
main  of  amphibolites  and  hornblendic  schists,  certainly  derivative 
from  igneous  rocks.  Near  the  younger  granitic  rocks  the  hornblende- 
schists  are  occasionally  so  far  reconstituted  as  to  form  massive 
diorites. 

Mica-schists,  talc-schists,  chloritic  schists,  and  siderite-schists 
also  occur  in  the  Pilbara  area,  but  the  most  remarkable  rock  here, 
as  in  the  other  auriferous  areas,  is  the  banded  hsematite-magnetite- 
quartz  rock,  identical  with  that  noted  in  the  Indian,  Rhodesian, 
and  Eastern  Transvaal  belts.  Here,  also,  it  forms  narrow  bands  or 
beds  30  to  60  feet  wide,  running  for  long  distances  parallel  to  the 
foliation  and  direction  of  the  main  belts,  and  furnishing  the  saw- 
toothed  and  serrated  ridges  that  occupy  such  a  prominent  position 
in  a  greenstone-schist  landscape. 

On  the  Kalgoorlie  goldfield,  where  the  rocks  have  been  most 
closely  examined,  in  addition  to  the  prevailing  amphibolites  and 
hornblende-schists  that  carry  the  auriferous  lodes,  there  also  occurs 
a  series  of  sedimentary  rocks  ranging  from  soft  shales  and  sand- 
stones to  slates  and  quartzites.  The  first  are  often  highly  graphitic, 
containing  numerous  nodules  and  crystals  of  iron  pyrites. 


WESTERN     AUSTRALIA.  389 

Everywhere  the  auriferous  series  is  intruded  by  numerous, 
often  parallel,  diabasic  and  doleritic  dykes.  These  are  generally 
vertical,  and,  as  will  be  seen  later,  they  have  exercised  a  notable 
effect  in  the  formation  of  the  younger  gold  deposits.  In  addition 
to  the  basic  intrusions,  there  are  found  a  great  number  of 
acidic  dykes,  which  may  be  regarded  as  apophyses  from  the 
younger  granites.  These  range  from  granites  through  aplites 
to  rock,  which  may,  in  hand  specimens,  almost  be  termed 
vein-quartz.  They  appear,  however,  to  have  had  no  effect  on 
auriferous  deposition,  and  are  themselves  barren. 

In  the  Pilbara  district  the  steeply-inclined  schists  are 
overlain  by  a  fairly  horizontal  series  of  sandstones,  grits, 
conglomerates,  and  thin  limestones,  associated  with  amygdaloidal 
diabase  and  felsitic  volcanic  rocks,  as  their  basal  members." 
To  this  series  the  term  "  Nullagine  beds  '  has  been  given.  The 
presence  of  the  amygdaloidal  diabase  is  noteworthy,  and  may  afford 
a  clue  to  the  age  of  the  basic  intrusive  dykes  of  the  auriferous  series. 
Again  overlying  the  Nullagine  beds,  and  with  apparent  uncon- 
formity, is  the  extensive  deposit  of  limestones,  which  forms  charac- 
teristic mesas,  and  has  from  the  place  of  its  greatest  develop- 
ment, been  termed  the  "  Oakover  beds."  All  these,  in  their  general 
characters,  correspond  very  closely  with  the  Cuddapahs  and 
associated   Karnuls  of  India. 

Three  main  forms  of  auriferous  deposits  may  be  distinguished 
in  Western  Australia  :  (a)  "  Lode  formations."  (b)  Banded-hsema- 
tite-magnetite-quartz  rock.  (c)  Normal  quartz  veins.  The  first 
form  furnishes  the  most  important  matrix  of  gold  in  the  State,  and 
is  especially  well  developed  at  Kalgoorlie,  Kanowna,  and  Peak  Hill. 
"  Lode  formations  "  are  merely  zones  of  rock  impregnated  with 
fine  gold  and  with  tellurides  of  gold.  They  merge  insensibly  into 
barren  solid  rock  on  either  side,  and  are  probably  belts  of 
sheared  and  fissured  rocks,  through  which  mineral  solutions,  liquid 
or  gaseous,  have  had  free  passage.  They  have  naturally  no  well- 
defined  walls,  and  their  limits  are  determined  solely  by  their 
assay  values.  The  normal  change  produced  in  the  hornblendic 
schists  in  these  zones  seems  to  be  the  development  of  chloritic 
schists. 

According  to  Lindgren,6  the  general  alteration  of  the  country 
has  been  by  metasomatic  processes  from  an  amphibole-chlorite- 
zoisite-albite   rock   to    a   quartz-sericite-albite-carbonate  rock.     He 

a  Maitland,   Bull.   West  Aust.   Geol.  Surv.   No.   15. 
b  Econ.  Geol.,  I,  1906,  p.  539. 


390  AUSTRALASIA. 

concludes  that  all  the  evidence  presented  by  the  Kalgoorlie  vein- 
minerals  points  to  a  genesis  of  the  veins  at  considerable  depth. 

The  laminated  haematite-quartz  rocks  enclose  a  class  of 
ore-bodies  of  quite  subordinate  economic  importance.  They  are 
developed  only  on  the  northern  goldfields  to  any  extent, 
notably  on  the  Lennonville  and  Boogardie  fields,  and  also  on 
the  fields  to  the  north  of  Lake  Austin.  The  quartzites  them- 
selves are,  moreover,  not  innately  auriferous,  and  it  is  only 
where  they  are  crossed  by  basic  dykes,  faults,  or  cross-veins 
that  they  carry  gold,  and  then  for  only  a  few  feet  on  either 
side  of  the  intersection.  Since  the  quartzites  generally  range  from 
30  to  60  feet  in  width,  and  since  the  intersections  are  always  at  right 
angles,  the  shoots  thus  formed  are  extremely  narrow/' 

Quartz  veins  are  responsible  for  the  gold  on  the  majority  of 
Western  Australian  fields,  and  may  fairly  clearly  be  divided  into  two 
classes,  viz.,  blue  and  white.  As  a  general  rule,  the  former  pre- 
vails on  the  northern  goldfields  and  the  latter  on  the  southern. 
No  clear  distinction  as  to  their  age  has  yet  been  made,  but  the 
white  veins  appear  to  be  the  younger  since  they  cut  through  and 
mineralise  many  of  the  laminated  quartzites. b  Quartz  veins  nearly 
always  occupy  shearing  planes  parallel  to  the  plane  of  foliation,  and 
within  a  given  zone  the  country  may  be  so  thoroughly  traversed  by 
them  as  to  form  a  stockwork.  The  more  massive  veins  are 
characterised  by  the  assumption  of  the  lenticular  habit. 

To  these  main  forms  of  gold  matrices  must  be  added  the  auri- 
ferous conglomerates  of  the  Nullagine  district.  These  furnish  a  very 
close  parallel  in  mode  of  formation  to  the  famous  "  banket  reefs  "  of 
the  Witwatersrand.  They  have  been  described  by  Maitland 
as  forming  the  Mosquito  Creek  Beds  towards  or  at  the  base  of  the 
Nullagine  series.  They  occur  in  lenticular  masses,  and  contain 
gold  both  in  thin  white  quartz  veins  parallel  to  the  bedding 
planes,  and  also  as  grains  interspersed  through  the  matrix  of  the 
conglomerate.  The  veins  are  much  richer  than  the  conglomerates, 
the  former  averaging  2-82  ounces,  the  latter  only  0-62  ounce  per 
ton.  Not  the  least  characteristic  feature  of  the  southern  gold- 
fields  of  Western  Australia,  and  especially  of  Kalgoorlie,  is  the 
occurrence  of  tellurides  of  gold  and  silver. 

"  Maitland,  Ann.  Rep.  West  Aust.  Geol.  Surv.,  1903,  p.  10. 
6  lb.,   1902,  p.    1G. 


WESTERN     AUSTRALIA. 


391 


The  following  table  shows  the  gold-yield  of  Western  Australia 
from  1886  to  the  end  of  1907  :- 


Year. 

Crude  Ounces. 

Value,  Sterling. 

1886 

302 

£1,148 

1887 

4,873 

18.517 

1888 

3,493 

13,273 

1889 

15,493 

58,872 

1890 

22,806 

86.664 

1891 

30,311 

115,182 

1892 

59,548 

226,284 

1893 

110,891 

421.385 

1894 

207,131 

787,099 

1895 

231.513 

879,748 

1896 

281.265 

1,068,808 

1897 

674,993 

2,564,977 

1898 

1,050.184 

3,990.698 

1899 

1.643,877 
Fine  Ounces. 

6,246,733 

1900 

1,414,311 

6,007,610 

1901 

1,703,417 

7,235,653 

1902 

1,871,037 

7,947,662 

1903 

2,064,801 

8,770,719 

1904 

1,983,230 

8,424,226 

1905 

1,955,316 

8,305,654 

1906 

1.794,547 

7,622,749 

1907 

1.697,552 

7,202.411 

Total  to  end") 
of  1907  . .  ) 

18,363,786 

£77,996,071 

Kimberley. — The  Kimberley  field  is  the  most  northerly  gold- 
field  of  Western  Australia.  It  lies  on  the  South  Australian  border, 
and  about  the  18th  parallel  of  south  latitude.  It  was  discovered 
in  1882  by  Mr.  E.  T.  Hardman,  then  Government  Geologist  of 
Western  Australia,  and  was  proclaimed  in  1886.  The  rocks  of  the 
district  are  Archaean  crystalline  schists  overlain  by  Cambrian, 
Devonian,  and  Carboniferous  rocks.  The  reefs  lie  in  the  schists,  and 
in  the  associated  granitoid  gneisses/'  Greenstone-schists  form  the 
country  of  the  most  important  auriferous  reefs.  The  schists  are 
vertical,  or  nearly  so,  and  seem  to  be  arranged  in  a  series  of  folds, 
the  trend  of  which  has  been  modified  by  the  faulting  which  has  taken 
place  subsequent  to  the  formation  of  the  schists.  Observations  seem 
to  indicate  the  occurrence  of  a  double  foliation  in  the  district.6 
The  placer  deposits  were  thin  ;  the  reefs  are  irregular,  small,  and 
unpayable.     This  field  was  the  scene  of  the  disastrous  Kimberley 

a  Hardman,  Rep.  Geol.  Surv.  W.A.,  1885,  p.  22. 

b  Maitland,  Bull.  Geol.  Surv.  W.A.,  No.  15;    Id.,  Annual  Mines  Report,  1903,  p.  8. 


392  AUSTRALASIA. 


"  rush  "  of  the  'eighties.  The  period  of  greatest  production  was  in 
1887,  when  some  4,873  ounces  were  obtained.  The  field  is  now  almost 
deserted,  and  its  output  is  only  a  few  hundred  ounces  annually. 
The  total  production  of  the  Kimberley  field  to  the  end  of  1906  has 
been  13,911-4  fine  ounces  from  quartz,  and  1,771-49  ounces  fine 
gold  from  placer  deposits. 

Pilbara. — The  oldest  rocks  occurring  in  the  Pilbara  area  are 
granites  and  gneisses.  These  form  the  platform  on  which  the  newer 
formations  were  laid  down,  and  everywhere  underlie  the  deposits  of 
the  great  plains  extending  from  Port  Hedland  to  Doolena  Gorge 
on  the  Shaw  River.  To  the  gneissoid  rocks  succeed  greenstone- 
schists  and  allied  rocks,  occupying  an  extensive  area  of  country  and 
appearing  to  be  almost  everywhere  genetically  connected  with  the 
occurrence  of  gold.  These  schists  are  associated  with  laminated, 
and  sometimes  hsematite-bearing,  quartzites.  The  rocks  of  the 
greenstone-schist  series  have  as  yet  not  been  closely  studied 
microscopically,  but  some  of  the  members  seem  to  owe  their 
origin  to  the  metamorphism  of  eruptive  rocks.  There  are,  however, 
associated  with  them,  rocks  of  undoubted  sedimentary  origin. 

Next  in  age  to  the  greenstone-schists  come  the  sandstones, 
grits,  conglomerates,  thin  limestones,  and  associated  volcanic  rocks 
that  are  so  well  exposed  in  many  parts  of  the  district.  These  are 
grouped  together  as  the  Nullagine  Beds.  This  formation,  the  actual 
base  of  which  can  rarely  be  seen,  forms  an  important  feature  in  the 
geology  of  Pilbara.  On  the  strength  of  the  lithological  and 
structural  similarity  to  those  of  the  Leopold  Range  in  Kimberley, 
the  Nullagine  Beds  are  assumed  to  be  of  the  same  age,  viz.,  Cambrian. 
Above  the  Nullagine  Beds  come  the  sandstones,  limestones,  cherts, 
&c,  that  form  the  table-topped  hills  in  the  vicinity  of  the  Oakover 
river.  These  do  not,  so  far  as  has  yet  been  observed,  occupy  any 
very  extensive  area  of  country,  nor  are  they  very  thick.  They 
are  known  as  the  Oakover  Beds.  Basic  igneous  rocks  are  intrusive 
into  the  schists,  gneisses,  and  granites,  and  often  form  very  con- 
spicuous features  in  the  landscape,  owing  principally  to  their  black 
weathered  summits  standing  out  in  bold  relief.  Wherever  good 
sections  can  be  seen  of  these  dykes,  they  are  generally  vertical. 
They  do  not  attain  any  very  great  width,  and  have  nowhere  been 
seen  to  pierce  the  Nullagine  Beds. 

The  general  direction  of  the  auriferous  belts  almost  everywhere 
coincides  with  the  strike  of  the  greenstone-schists,  which,  with 
few  exceptions,  form  the  country  of  the  auriferous  reefs.  The 
width  of  a  belt  naturally  varies,  and  in  the  three  most  northerly 
zones  the  exact  width  cannot  be  defined.  The  prevailing  dip  is  that 
of  the   enclosing   schists,   which   is    generally  to    the    southward. 


WESTERN     AUSTRALIA.  393 

Quartz  reefs  occur  in  great  abundance  throughout  the  schistose  rocks, 
and,  to  a  more  limited  extent,  in  the  area  occupied  by  the  granitic 
rocks.  The  quartz  reefs  are  of  two  distinct  types,  viz.,  white  quartz 
reefs,  and  laminated  quartz  and  jasper  veins,  the  latter  approaching 
very  closely  in  character  the  haematite-bearing  quartzose  rocks  to 
which  allusion  has  already  been  made.  It  is  indeed  from  one  of 
these  beds  of  laminated  quartz  rocks  at  the  Coongan  river  that  the 
chief  camp  of  Marble  Bar  derives  its  name.  The  laminated  rocks 
range  from  almost  pure  quartz,  through  banded  jaspers,  with 
crystals  of  magnetite,  to  bands  appearing  to  the  eye  to  be  virtually 
pure  haematite.  Quartz  reefs  of  what  may  be  termed  the  massive 
type  occur  plentifully  in  both  the  schist  and  the  granite  areas, 
but  it  is  only  in  the  former  that  the  laminated  and  iron-bearing 
quartz  rocks  have  been  found.  The  reefs  nearly  always  occur 
along  the  planes  of  foliation  of  the  schists.  They  cannot  be  said 
to  be  of  great  length,  and  as  a  rule  are  thin,  though  they  may 
occasionally  swell  out  into  large  lenticular  masses.  Shoots  occur 
in  the  veins." 

The  principal  mining  camps  of  the  Pilbara  field  are  Marble  Bar 
and  Nullagine.  The  greater  part  of  the  goldfield  lies  north  of  the 
22nd  parallel  of  south  latitude,  and  east  of  the  119th  meridian. 
The  goldfield  was  proclaimed  in  1895  and  to  the  end  of  1906  had 
produced  from  23,725  tons  ore,  42,626  ounces  fine  gold,  in  addition 
to  308  ounces  from  specimen  stone  and  4,007  ounces  from  the 
alluvial.  The  output  of  the  field  has  recently  diminished,  but  the 
completion  of  the  projected  railway  from  Port  Hedland  to  Marble 
Bar,  will,  it  is  believed,  assist  the  field  materially. 

West  Pilbara.— The  West  Pilbara  field  lies  between  the  Pilbara 
field,  and  the  north-western  coast  in  the  neighbourhood  of  Cossack. 
At  the  Mallina  Diggings  the  gold  is  associated  in  the  veins  with 
stibnite.  Their  present  yield  is  small.  The  greater  part  of  the  gold 
produced  to  the  end  of  1906  has  come  from  the  Pilgrim's  Rest  leases 
at  Station  Peak,  which  have  produced  9,'151  ounces,  out  of  the  total 
of  12,752  ounces  vein  gold  for  the  field  ;  to  this  is  to  be  added  3,255 
ounces  placer  gold.  The  veins  at  Station  Peak  are  in  schists  in- 
truded by  diabase  or  diorite  dykes. 

Ashburton. — The  Ashburton  field  lies  along  the  basin  of  the 
Ashburton  river,  which  reaches  the  sea  at  Onslow  on  the  north-west 
coast.  Little  is  known  geologically  of  the  country,  and  nearly  all 
of  the  gold  recovered  (7,265  ounces)  has  been  from  placer  deposits, 
and  has  probably  either  been  derived  from  veins  in  clay-slates 
or  from  conglomerates  similar  to  those  of  the  Nullagine  series.^ 

"Maitland,  Bull.  W.A.  Geol.  Surv.,  No.   15. 

b  Woodward,  Ann.  Gen.  Rep.  Dept.  Mines,  189Q,  p.  21. 


394  AUSTRALASIA. 

Gascoyne.— The  Gascoyne  Goldfield  is  of  no  present  importance, 
having  produced  to  the  end  of  1906  only  268  ounces  alluvial  and  218 
ounces  vein  gold,  the  latter  derived  from  Archaean  rocks. 

Peak  Hill.— The  mines  of  the  Peak  Hill  Goldfield  are  situated 
between  24°  and  26°  S.  lat.  and  117°  and  120°  E.  long.  Its  chief 
mining  camp  is  Peak  Hill.  The  country  is  banded  haematite-mag- 
netite-quartz rock,  micaceous  schist,  and  banded  or  granular  quartzite 
Intrusive  rocks  are  apparently  absent.  Great  veins  or  dykes  of 
quartz  cross  the  schistose  rocks.  These  are  slightly  auriferous  and 
cut  through  the  productive  gold-quartz  veins."  Depressions  in  the 
surface  of  the  schists  are  filled  by  an  iron-stained  well-cemented 
conglomerate  of  recent  age,  in  which  gold  occurs  both  free  in  grains, 
scales,  and  nuggets,  and  also  in  fragments  of  the  original  quartz 
matrix. 

Gold  is  found  in  the  schists  in  interlacing  quartz  veinlets  dis- 
posed along  bands  of  weathered  country,  and  is  also  disseminated 
through  the  adjacent  country.  Most  of  the  alluvial  gold  is  obtained 
by  dry-blowing.  The  total  output  of  vein  gold  obtained  from  vein- 
quartz  to  the  end  of  1906  was  204,518  ounces  fine,  of  which  the  Peak 
Hill  mine  alone  produced  196,289  ounces  fine  gold.  No  records  have 
been  kept  of  the  amount  of  alluvial  gold  obtained. 

Murchison. — The  geology  of  the  Murchison  field  is  now  fairly 
well  known.  The  auriferous  rocks  are  metamorphic  schist,  slate, 
quartzite,  and  ferruginous  sandstone,  with  which  are  associated 
granite  and  quartz-diorite.  Numerous  veins  occur  in  the  quartz- 
diorites.  The  ridges  of  the  county  are  generally  formed  by  the 
banded  ferruginous  quartzites,  at  the  intersections  with  which  the 
quartz  reefs  are  always  enriched.  Dykes  of  granite  and  quartz-diorite 
(approaching  tonalite)  are  numerous.  The  gangue  matrix  is  quartz, 
and  below  the  water  level  the  veins  contain  galena  and  pyrite.  The 
gold  occurs  in  shoots,  often  at  the  intersection  with  certain  beds.ft 

The  auriferous  rocks  of  the  northern  part  of  the  field  are  massive 
and  foliated  greenstone-schists,  including  diorites,  pyroxenites,  and 
amphibolites.  These  occur  in  belts,  some  of  which  are  of  great 
extent,  one  being  at  least  60  miles  long  by  10  to  15  miles  broad. 
The  auriferous  reefs  occur  almost  entirely  within  the  greenstone- 
schist  belts,  few  of  importance  traversing  the  granite.  The  granitoid 
rocks  vary  from  the  biotite-granite  of  Mount  Magnet  to  a  grano- 
diorite,  the  general  characters  of  which  are  well  described  by  Gibson.  c 
The  granodiorites  are  found  near  Cue  and  Nannine.     The  haematite- 

"  Maitland,   Bull.  Geol.   Surv.   W.A.,   No.  4,   1900,  p.  40. 
''Woodward,  Rep.  Dep.  Mines.  W.A.,  1893,  pp.  9-11. 

cBull.   Xo.    14,  Geol.  Surv.   W.A.,   1904,  p.    14. 


WESTERN     AUSTRALIA.  395 

quartzite  bands  in  the  schist  series  run  northward  with  the  schist 
belts  for  great  distances.  The  principal  centres  of  the  Murchison 
field  are  Mount  Magnet,  Day  Dawn,  Cue,  and  Nannine. 

The  Day  Dawn  area  contains  the  Great  Fingall  mine,  one  of  the 
most  celebrated  of  Western  Australian  mines.  Its  veins  lie  entirely 
within  the  greenstone-schists,  the  foliation  of  which  is,  however, 
apparent  only  in  weathered  specimens.  The  large  shoot  in  the 
Great  Fingall  had,  to  1906,  produced  804,854  tons  stone  of  an 
average  value  of  less  than  an  ounce  gold  per  ton,  or  in  all  749,446 
ounces.  The  shoot  occurs  at  a  turn  in  the  reef  and  has  been  followed 
down  for  more  than  1,300  feet.  The  zone  of  greatest  enrichment 
in  the  shoot  Avas  determined  by  the  junction  of  a  flat  lode  on  the 
footwall."  To  May,  1908,  the  Great  Fingall  mine  had  paid  £1,612,500 
in  dividends. 

The  Cue  veins  lie  at  the  contact  of  granodiorite  with  the  green- 
stone schists.  Some  of  the  veins  radiate  out  into  the  granitic  rock  ; 
the  others  lie  in  the  granodiorite  contact  zone,  and  run  parallel  with 
the  contact. 

At  Mount  Magnet  and  Boogardie  the  main  auriferous  series  is 
formed  by  a  belt  of  more  or  less  highly  altered  greenstones,  which 
extend  in  a  general  northerly  direction  from  West  Mount  Magnet 
through  Moyagee  as  far  north  as  Lake  Austin  and  the  town  of  Cue. 
The  belt  attains  a  maximum  width  of  about  15  miles,  and  includes 
diorite  and  pyroxenite,  together  with  hornblende-  and  chloritic 
schists  that  may  merely  represent  crushed  and  sheared  varieties  of 
the  former.  The  greenstones  are  intersected  by  numerous  faults, 
and  are  also  traversed  by  belts  of  laminated  quartzites  that  are 
often  highly  ferruginous,  and  that  are  raised  as  ridges  above  the 
surrounding  country. 

The  greenstones  are  bounded  on  either  side  by  beds  of  granite, 
from  which  small  tongues  of  aplite  emanate.  In  many  portions 
of  the  district  dykes  of  granite  intersect  the  greenstone.  The 
foliation  of  the  greenstone  seems  to  have  taken  place  prior  to  the 
intrusion  by  the  granite.  The  laminated  haematite-magnetite- 
quartz  rocks  of  Boogardie  are  traversed  by  numerous  faults,  the 
mapping  of  which  is  of  considerable  importance  from  a  mining  point 
of  view,  inasmuch  as  it  is  along  the  intersection  of  these  faults  with 
the  laminated  quartzites  that  the  rich  shoots  of  gold  for  which  the 
district  is  famous  occur.  W7herever  seen,  the  faults  cross  the  strike 
of  the  quartzites  at  right  angles,  and  as  the  latter  are  generally 
only  from  30  to  60  feet  in  width,  it  necessarily  follows  that  the 
width  of  the  ore-shoots  is  also  small,  more  particularly  as  they  never 
continue  into  the  country  on  either  wall.     The  fault-fissures  are 

a  Woodward,  Rep.   Dept.  Mines,  W.A.,   1906,  p.   150. 


396  AUSTRALASIA. 

invariably  filled  with  brecciated  quartzite,  re-cemented  by  chalce- 
donic  quartz  and  traversed  by  small  angular  quartz  veins.  The 
fissures  vary  from  3  to  6  feet  in  width. 

Quartz  reefs  occur  plentifully  in  both  the  granite  and  the  green- 
stone, though,  as  a  rule,  it  is  only  those  close  to  the  greenstone  which 
have  proved  to  be  auriferous  to  any  extent.  The  shoots  in  these 
reefs  are  short,  but  frequently  rich.  It  is  interesting  to  note  that 
the  quartz  reefs  often  form  the  continuation  of  the  faults  by  which 
the  laminated  quartzites  are  intersected. 

The  total  yield  for  the  Murchison  field  to  the  end  of  1906  is  as 
follows  : — 


Fine  Ounces. 

Alluvial. 

Vein. 

Cue          

Nannine 
Day  Dawn 
Mount  Magnet 

575 
6,452 

975 
1.150 

9.152 

212,280 
202,946 
846,718 
249,627 

Total 

1.151.571 

Yalgoo. — The  Yalgoo  field  lies  in  foliated  greenstone  schists. 
Its  veins,  and  particularly  the  Emerald  Reef,  were  very  rich  at  the 
surface,  but  have  not  been  profitable  in  depth.  Only  about  4,000 
ounces  fine  gold  are  produced  annually.  The  schists  are  traversed 
by  numerous  diorite  dykes,  which,  as  well  as  the  reefs,  strike  east 
and  west  with  the  foliation  of  the  schists.*  To  the  end  of  1906  the 
field  had  produced  59,962  ounces  gold. 

East  Murchison. — The  principal  mining  centres  of  the  East 
Murchison  field  are  Lawlers,  Lake  Darlot,  Mount  Sir  Samuel,  Lake 
Way,  and  Black  Range.  The  country  is  the  usual  Archaean  schist, 
associated  with  granites  and  gneisses,  and  intruded  by  basic  rocks. 
The  Lake  Darlot  field  was  formerly  one  of  the  chief  alluvial  fields  of 
the  State,  but  its  placers  are  now  exhausted.  At  Lawlers  the  reefs 
occur  along  the  zone  of  contact  between  the  gneissic  granite  and  the 
greenstone  schists.  Numerous  acidic  (granitic  and  felsitic)  veins 
break  through  the  greenstone-schist,  and  with  these  are  associated 
the  gold-quartz  reefs. 

The  principal  mine  is  the  East  Murchison  United.  Its  quartz 
veins  are  intersected  by  felsitic  dykes.  The  auriferous  belt  in 
general  has  a  width  of  12  to  16  miles,  and  is  continuous  between 
Lawlers  and  Mount   Sir  Samuel,  disappearing  at  Abbots,  a  little  to 


"  Woodward,  Rep.   Depfr.  Mines,  1895,  pp.  21-22. 


WESTERN     AUSTRALIA.  397 

the  north  of  Mount  Sir  Samuel.     It  has  thus  a  total  length  of  some 
50  to  60  miles.     The  ore  deposits  are  of  the  following  types  :  — 

(a)  Reefs  at  contact  of  greenstones  and  granite. 

(b)  Normal  quartz  reefs  (fissure  veins). 

(c)  Lode-formations. 

Reefs  of  the  second  class  are  found  both  in  the  granites  and  in 
the  greenstones,  but  it  is  only  in  the  latter  that  they  are  auriferous. 
As  a  rule,  the  reefs  of  Lawlers  are  large  and  low  grade." 

Mount  Sir  Samuel  is  32  miles  north  of  Lawlers.  Its  rocks  are 
hard,  unweathered,  greenstone  schists  intersected  by  numerous 
granitic  dykes. 

The  Black  Range  district  in  the  west  of  the  East  Murchison 
field  is  characterised  in  its  schist-belts  by  the  banded  or  laminated 
hsematite-quartzites  which  here  appear  to  occupy  lines  of  faulting 
since  they  disturb  the  older  auriferous  veins.  The  returns  from  the 
two  divisions  of  the  East  Murchison  fields  to  the  end  of  1906  are  :  — 


Fine  Ounces. 

Alluvial. 

Vein. 

Lawlers 
Black  Range 

4.441 

8S6 

576,663 
63,518 

Mount  Margaret — In  the  Mount  Margaret  goldfield,  the 
principal  areas  are  Laverton  (Mount  Margaret),  Mount  Morgan,  and 
Mount  Malcolm.  Leonora  is  the  principal  mining  camp  of  the 
Mount  Malcolm  district,  and  contains  one  well-known  mine,  the 
Sons  of  Gwalia.  This  mine  has  produced  since  mining  operations 
commenced  445,591  ounces  from  716,549  tons  ore.  Its  vein  is  in  an 
impregnated  zone  or  "  lode-formation  '  containing  numerous 
lenticles  of  quartz.  The  workable  width  of  the  lode  is  determined 
entirely  by  assay.     The  gold  occurs  in  pay-shoots. 

The  country  of  the  Leonora  belt  must  be  regarded  as  a  single 
area  of  basic  rock,  which  has  been  more  or  less  crushed,  foliated,  and 
completely  converted  into  schists,  the  latter  structure  being  on  the 
whole  the  most  usual  ;  to  such  schistose  zones  the  auriferous  reefs 
are  almost  entirely  confined.  The  greenstone  on  the  eastern  side 
of  the  belt  is  highly  metamorphosed,  the  great  development  of  the 
banded  and  haematite-bearing  quartz-rock  forming  one  of  the  most 
notable  scenic  features  of  the  district.  Along  the  summit  of  the 
ridge,  extending  from  Mount  George  to  Leonora,  and  thence  to  Lake 
Raeside,  outcrops  of  this  quartz  are  found  in  the  form  of  bands  or 
lenses,  from  200  yards  to  more  than  half-a-mile  in  length,  and  from 


"Gibson,  Ann.   Rep.  Mines  Dept.   W.A.,   1906,  p.   154. 


398  AUSTRALASIA. 

1  foot  to  100  feet  in  thickness,  and  projecting  several  feet  above 
the  surface  in  the  form  of  perpendicular  walls.  The  best  veins  on 
the  Leonora  field  occur  near  the  contact  of  the  granite  and  the 
schists.  Veins  carrying  gold  are  known  to  pass  from  the  schist  into 
the  granite. 

The  Mount  Morgan  district,  like  the  Mount  Malcolm,  possesses 
one  mine  of  outstanding  importance,  viz.,  the  Westralia  Mount 
Morgans.  Its  outcrop-ore  was  exceedingly  rich,  3,000  tons  yielding 
at  the  rate  of  4 J  ounces  gold  per  ton.  The  ore  occurs  in  lenses  in 
the  schists,  the  lenses  having  an  average  width  of  100  feet,  and 
overlapping  each  other.  The  gold  is  found  in  shoots  within  the 
lenses.  To  a  depth  of  150  feet,  the  oxidised  ore  yielded  2  ounces 
per  ton,  but  in  the  sulphide  zone  the  average  value  of  the  ore 
crushed  has  been  11  dwts.  To  the  end  of  1906  239,461  fine 
ounces  gold  had   been  obtained  from  386,221  tons  ore. 

The  Laverton  (Mount  Margaret)  district  contains  several 
valuable  mines  ;  the  most  prominent  are  the  Ida  H.  (Laverton) 
with  a  yield  of  57,792  ounces,  the  Craggiemore  (Laverton)  with 
35,336  ounces  to  the  end  of  the  year  1906,  and  the  Lancefield, 
with  a  yield  in  1907  worth  £25,993.  Its  geological  characters  are 
similar  to  those  of  the  already  described  fields. 

The  various  districts  of  Mount  Margaret  field  have  yielded,  to 
the  end  of  1906,  as  follows  : — 


Fine  Ounces. 

Alluvial. 

Vein. 

Mount  Malcolm 

Mount  Morgan 

Laverton  (Mount  Margaret)  .  . 

1,442 

345 

1,233 

663,082 
367,333 
310,091 

North  Coolgardie. — The  North  Coolgardie  field  is  divided  into 
four  districts  :  Menzies,  Ularring,  Niagara,  and  Yerilla.  Its  geo- 
logical characters  are  identical  with  those  of  Kalgoorlie  and  Cool- 
gardie further  south.  The  Menzies  goldfield  has  been  described  by 
H.  P.  Woodward."  The  country  of  the  auriferous  veins  is  a  hard 
greenstone-schist,  displaying,  as  is  often  the  case,  schistosity  only  in 
the  zone  of  weathering.  Both  basic  (amphibolite-)  and  acid  schists 
occur,  the  latter  being  sericite-schist  and  gneiss.  Numerous  felsitic 
dykes  are  intrusive  into  the  basic  schists.  The  richer  auriferous 
veins  of  the  Menzies  district  are  irregular  segregation  veins,  occurring 
either  as  pipes  or  as  a  series  of  lenticular  masses.  The  gold  occurs 
in  shoots  in  the  quartz.  The  greatest  depth  to  which  a  shoot  has 
been  worked  is  the  1,600  feet  reached  in  the  Queensland   Menzies 


°  Bull.   Geol.   Surv.    W.A.,    No.    22,    190G. 


WESTERN     AUSTRALIA.  399 

mine.  In  the  Lady  Shenton  mine  the  pipes  or  shoots,  though 
well-defined,  persisted  only  to  a  depth  of  800  feet. 

The  Ularring  district  lies  in  the  south-west  of  the  goldfield. 
Its  principal  centres  are  Ularring,  Davyhurst,  Mulline,  and  Mul- 
warrie.  Its  rocks  are  the  greenstone  schists  of  the  "  Auriferous 
Series."  The  veins  occur  mainly  in  lode-formations."  The  gold 
is  found  in  shoots. 

The  Niagara  district  has  only  one  large  mine,  viz.,  the  Cosmo- 
politan at  Kookynie,  which  to  the  end  of  1906  had  obtained  238,412 
fine  ounces  from  490,242  long  tons  ore.  Unlike  the  ore-bodies  of 
most  Westralian  goldfields,  its  veins  traverse  granite.  The  principal 
vein  is  from  6  to  10  feet  in  width. 

The  Yerilla  district  is  in  the  south-east  portion  of  the  North 
Coolgardie  field.  Its  chief  camps  are  Yarri,  Edjudina,  and  Pendinnie. 
At  Eucalyptus,  in  the  Edjudina  district,  the  diabase  rock  is  so  closely 
intersected  by  quartz  veins  as  to  form  an  auriferous  stock. 

The  following  table  shows  the  relative  importance  of  the 
various  districts  of  the  North  Coolgardie  field  :  — 

Yield  to  end  of  1906. 


Menzies 
Ularring 
Niagara 
Yerilla 


Fine 

Ounces. 

Alluvial.6 

Vein. 

950 

5 

300 

1.018 

485.217 
179,308 
394.928 
110,177 

Yilgarn. — Southern  Cross,  the  principal  district  of  the  Yilgarn 
goldfield,  was  opened  in  1887.  The  rocks  of  the  Yilgarn  Hills  and  of 
Southern  Cross  are  mica-schist,  mica-slate,  and  shaly  quartzite, 
with  many  diorite  dykes  and  quartz  veins.  The  schistose  rocks 
have  been  intruded  by  granite  at  Southern  Cross  itself.  The  country 
of  the  veins  is  a  hornblende-schist.  The  principal  vein  is  Fraser's, 
in  which  the  ore  occurs  in  lenticular  shoots.  The  yield  of  gold  from 
Yilgarn  to  end  of  1906  has  been  267,128  ounces  gold  from  623,677 
tons  ore  crushed. 

Coolgardie. — The  Coolgardie  goldfield  is  divided  into  two  dis- 
tricts, Coolgardie  and  Kunanalling.  The  Coolgardie  mines  were 
the  earliest  discovered  of  the  great  mines  of  Western  Australia. 
Alluvial  gold  was  found  in  June,  1892,  and  three  months  later  the 

a  Gibson,  Bull.  Geol.  Surv.  W.A.,  No.   12,  1903. 

"  The  official  return  of  alluvial  gold  is  always  less  than  the  true  output,  and  is  often, 
indeed,  only  a  small  fraction  of  it. 


400  AUSTRALASIA. 

rich  outcrop  of  the  Bayley's  Reward  Reef 'was  uncovered  by   the 
original  prospectors,  Bay  ley  and  Ford. 

The  schists  of  Coolgardie  belong  to  the  main  Auriferous 
Series  of  Western  Australia.  They  lie  as  long  narrow  hornblendic 
and  talcose  belts  in  granitic  rocks/1  The  schistose  structure 
is  developed  only  in  weathered  zones.  Intrusive  through 
the  schists  are  numerous  diorites  and  acid  eruptive  rocks  that, 
as  a  rule,  conform  with  the  general  strike  of  the  enclosing 
rocks.  The  acid  intrusives  occur  as  narrow  dykes  trending  towards 
the  granite.  In  some  cases  they  may  be  seen  to  change  in  the 
direction  of  their  strike  from  a  coarse  granitic  type  to  a  highly 
quartzose  rock  (the  alaskite  of  Spurr).  These  quartzose  dykes  pass 
into  quartz  veins  that  are  invariably  barren,  although  leaders  or 
spurs  from  them  may  show  gold.  Vein  gold  occurs  at  Coolgardie, 
both  in  "  lode-formations  "  and  in  reefs.  The  former  are  generally 
lenticular  masses  of  highly  altered  schist,  through  which  run  numerous 
small  quartz  veinlets.  These  masses  invariably  thin  out  when 
harder  country  is  met  with,  though  the  quartz  veinlets  may  unite 
and  continue  as  a  strong  low-grade  reef.  The  boundaries  of  the 
"  lode-formations  "  may  be  determined  only  by  assay.  On  the 
whole,  they  have  not  proved  of  great  economic  importance.  The 
quartz-reefs  also  occur  in  the  schists,  either  as  well-defined  continuous 
veins  or  more  generally  as  lenses  connected  in  strike  only  by  fissure 
planes.  Lenses  parallel  in  strike  and  dip  often  overlap  both 
horizontally  and  vertically.  The  gold  occurs  in  shoots  of  great  value 
and  is  nearly  always  enclosed  within  a  quartz  matrix.  The  minerals 
ordinarily  associated  in  the  vein  with  the  gold  are  pyrites,  mispickel, 
sulphides  of  copper,  and  arsenopyrite.  The  last  is  considered  the 
associate  most  favourable  for  gold.  Pyrrhotite  also  is  met  with. 
Molybdenite  and  galena  are  rare. 

The  principal  mines  of  Coolgardie  in  1907  were  the  Bayley's 
and  Bayley's  Consols.  The  former  had  produced  to  the  end  of 
1906  more  than  100,000  ounces  of  fine  gold.  The  majority  of  the 
Coolgardie  veins  failed  in  depth  and  the  camp  at  the  present  time 
shows  but  little  activity.  In  the  early  days  of  the  field,  rich  alluvial 
deposits  were  found  in  the  vicinity.  The  largest  nugget  unearthed 
weighed  607  ounces  in  the  crude  state. 

The  mining  centres  outside  Coolgardie  are  of  comparatively 
little  importance.  They  are  Bonnievale,  where  the  veins  are  in 
hard  grey  granite,  and  Burbanks,  where  one  mine  had  produced, 
to  the  end  of  1906,  gold  to  the  amount  of  126,352  fine  ounces. 

The  Kunanalling  division  lies  to  the  north  of  Coolgardie. 
It  is  widely  known  rather  on  account  of  its  rich  cement-deposits 

"  Blatchford,  Bull.  W. A.  Cool.  Surv.,  No.  3,  1899. 


WESTERN     AUSTRALIA.  401 

than  for  gold-quartz  veins.  The  cement  is  similar  to  that 
at  Kanowna,  consisting  of  rounded  and  sub-angular  fragments 
cemented  by  ferruginous  silicate  of  alumina.  The  gold,  almost 
without  exception,  occurred  in  the  cement,  and  was  largely  derived 
from  neighbouring  veins,  though  a  small  portion  may  have  been 
deposited  from  solution. 

Broad  Arrow. — The  Broad  Arrow  goldfield  is  one  of  the 
smallest  of  the  West  Australian  goldfields,  having  an  area  of  only 
590  square  miles.  Its  principal  camps  are  Black  Flag,  Paddington, 
Broad  Arrow,  and  Bardoc.  The  rocks  are  similar  to  those  of  Cool- 
gardie,  the  basic  schists  being  intruded  by  numerous  acidic  dykes. 
With  Coolgardie,  Kalgoorlie,  and  Kanowna,  it  has  furnished  the 
bulk  of  the  placer  gold  of  the  State.  Its  officially  recorded  yield  of 
alluvial  gold  has  been  15,790  fine  ounces,  and  of  vein  gold,  247,985 
fine  ounces. 

East  Coolgardie  — The  East  Coolgardie  goldfield,  comprising 
an  area  of  only  632  square  miles,  includes  the  world-famous  Kal- 
goorlie camp  with  its  "  Golden  Mile."  The  chief  mines  of  Kalgoorlie 
are  the  Great  Boulder,  Ivanhoe,  Horseshoe,  Perseverance,  Oroya- 
Brownhill,  Associated,  and  Lake  View  Consols.  The  deepest  shaft 
is  that  of  the  Boulder,  which  is  more  than  2,000  feet  in  depth.  The 
productive  rocks  of  the  field  are  comprised  within  a  long  narrow 
belt,  flanked  by  granites  and  gneiss.  The  schists  are,  in  the  main, 
amphibolitic  where  they  have  been  derived  from  original  igneous 
rocks.  Rocks  representing  original  sedimentary  beds  occur  in  the 
form  of  soft  graphitic  shales,  sandstones,  jasperoid  slate,  and  flinty 
quartzite.  Graphite,  to  the  extent  of  5  per  cent,  or  more,  is  found 
with  the  slates,  and  the  latter,  when  graphitic,  often  contain  spherical 
nodules  of  pyrite  up  to  an  inch  in  diameter.  Sand  grains  may 
increase  to  grits,  to  fine  conglomerates,  and  even  to  the  coarse 
boulder-beds  that,  elsewhere,  in  India  and  South  Africa,  are  charac- 
teristic of  this  type  of  Archaean  rock.  Apparently  to  be  associated 
with  the  amphibolitic  schists  are  chlorite-schists  and  massive  and 
foliated  siderite-rock.  Traversing  the  schists  are  numerous  intrusive 
dykes  of  felspar-porphyry,  porphyrite,  and  peridotite. 

The  lodes  of  Kalgoorlie  consist  of  a  series  of  almost  vertical 
schistose  "  lode -formations  '  that  strike  from  north-north-west 
to  west-north-west.  They  represent  zones  of  crushing  and 
Assuring  that  may  reach  to  100  feet  in  width.  The  deposits  are 
lenticular,  the  lenses  being  often  of  great  length,  with  generally  no 
well-defined  walls.  The  dip  of  the  lodes,  when  not  vertical,  is  to 
the  west,  but  it  may  occasionally  turn  over  to  the  east  for  short 
depths.  The  lode  matter  is  schistose  country  which  is  highly  silici- 
fied,  and  which  is  impregnated  with  pyrite,  tellurides  of  gold,  and 

Bl 


402 


AUSTRALASIA. 


Scale    -   Miles 


Fig.  139.     Geological  Sketch  Map  of  Kalgooklie  (Maitland  and  Campbell). 
1.    Slates,     schists,     and     quartzites.        2.    Graphitic    schists.        3.     Massive     hornblende-amphibolite. 
4.   Massive    amphibolite    (with    chlorite).     5.  Massive    amphibolite    (with    actinolite).     6.  Foliated  amphi- 
bolite.    7.  Porphyrite.     8.  Schisted      porphyrite.     9.  Felsite      dykes.     10.   Peridotite     (with     derivatives.) 
11.  Laterite.     12.  Superficial  deposits  (recent). 


WESTERN     AUSTRALIA.  403 

free  gold.     The  oxidised  zone  varies  in  depth  from  a  few  feet  to 
more  than  200  feet. 

The  lode  system  is  fairly  complex,  several  main  lodes  occurring 
with  minor  parallel  and  interlacing  veins  and  veinlets.a  The 
principal  lodes  or  ore-bodies  on  the  western  side  of  the  belt  are  the 
Brownhill,  Australian  East,  Tetley's,  Kalgurli  East  and  West,  Lake 
View  Consols,  and  Boulder  Perseverance.  On  the  eastern  side  the 
main  lodes  are  the  Hainault,  Great  Boulder,  Horseshoe,  Boundary, 
Ivanhoe  East,  Ivanhoe  New,  and  Ivanhoe  Middle.  Of  all  the 
famous  shoots  of  Kalgoorlie,  the  Brownhill  has  probably  been  the 
most  productive.  This  shoot  passes  through  several  mines  dis- 
posed along  the  strike  of  the  lode  ;  it  is  estimated  that  more  than 
£4,000,000  has  been  obtained  from  it.  The  total  yield  of  the  East 
Coolgardie  goldfield  to  the  end  of    1906  has  been   8,162,035  fine 


100  f set 


Fig.  140.     Ore-bodies  in  schisted  band,  Lake  View  Consols  Mine,  Kalgoorlie 

(Richard). 

ounces   from    7,805,455    tons    of    ore,    in   addition  to    16,580    fine 
ounces  alluvial  gold,  the  whole  being  worth  some  £34,742,000. 

Kalgoorlie  competes  with  Cripple  Creek  in  Colorado  for  the 
distinction  of  being  the  richest  telluride  goldfield  in  the  world. 
The  tellurides  occurring  are  calaverite,  krennerite,  sylvanite,  petzite, 
and  nagyagite.  Free  gold  is  abundant  in  the  upper  levels,  and  has 
apparently  been  derived  from  the  decomposition  of  tellurides  or  of 
auriferous  pyrites.  Dendritic  gold  is  riot  uncommon.  That  pro- 
duced from  the  oxidation  of  the  tellurides  is  locally  known  as 
"  paint  "  gold,  "  mustard  "  gold,  and  ;'  sponge  "  gold,  all  three 
terms  being  sufficiently  self-explanatory.  A  mass  of  "  sponge  " 
gold,  weighing  about  70  lbs.,  was  taken  from  a  vugh  at  the  200-foot 
level  of  the  Great  Boulder  Proprietary  mine.  The  fineness  of  this 
secondary  gold  is  very  high,  and  ranges,  indeed,  from  900  to  999-  1, 
the  last  assay  coming  from  the  Boulder,  Kalgoorlie,  and  representing 
probably  the  purest  natural  gold  known,  finer  even  than  that  of 
Mount  Morgan.  The  average  fineness  of  twelve  samples  assayed 
by  E.  C.  Simpson  was  917-  7. 

ttMaitland,   Bull.   Geol.   Surv.   W.A.,  No.  4,   1900,  p.   63. 


404  AUSTRALASIA. 

At  Kalgoorlie  the  tellurides  in  the  deeper  zones  are  normally 
massive,  while  the  pyrite  is  often  finely  divided.  Accessory  or 
secondary  minerals  in  the  lodes  are  chalcopyrite,  blende,  galena, 
coloradoite,  pyrargyrite,  enargite,  lollingite.  fluorite,  magnetite f 
rutile,  calcite,  dolomite,  siderite,  ankerite,  sericite,  chlorite,  and 
roscoelite/'  to  which  may  be  added  albite^  and  tourmaline.6' 
Albite  is  fairly  common  in  the  lode  formations. 

The  lenses  of  schistose  country  that  contain  the  telluride  ores 
are  often  disposed  en  echelon,  overlapping  each  other  both  horizon- 
tally and  vertically.  The  width  of  the  lodes  is  determined  only  by 
the  width  of  ore  removed,  and  that  again  is  regulated  by  the  costs 


\  \  it'L 

i  i--     i    *■  A-  '\    ^  \ 


\\\>\)m&^A 


i 
\ 


Fig.  141.     Great  Boulder  Maes  Lode,  Kalgoorlie 
( Richard). 

Quartz  and  calcite  gangue  in  schistose  country  with  one  well-defined  wall,  AF. 

prevailing  at  the  given  mine.  The  general  character  of  the 
Kalgoorlie  oxidised  ores  is  indicated  by  the  following  determina- 
tions on  free  silica  : — 

Hannan's  Brownhill    .  .  .  .  .  .  .  .  18-21  per  cent. 

Lake  View  Consols      ..  ..  ..  ..         28-31         ,, 

Boulder  Main  Reef 31-06 


a  Simpson,   Bull.   Geol.  Surv.   W.A.,  No.   6,  p.   21. 

6  Lindgren,  Econ.  Geol.,  I,   1906,  p.  534. 

c  Spencer,  Min.  Mag.,  XIII,  1901-1903,  p.  268. 


a 

EH 

1= 

O 
VI 

H 

K 

g 
O 
« 

fa 


o 
o 


WESTERN     AUSTRALIA.  405 

The  only  other  gangue  mineral  of  importance  is  kaolin.  In 
unoxidised  ores  more  quartz  is  present.  Lateral  impregnation  of 
gold  in  the  decomposed  country  rock  in  the  oxidised  zone  has  been 
general  and  is  clearly  evidenced  by  the  almost  invariable  rule  that 
the  stopes  are  often  twice  as  wide  in  the  oxidised  portion  as  in  the 
lower  sulphide-telluride  zone/' 

North-East  Coolgardic  — The  principal  camp  of  the  North- 
east Coolgardie  Field  is  Kanowna.  Its  rocks  are  highly  decomposed, 
serpentinous,  chloritic,  and  talcose  schists,  intruded  by  acid  eruptive 
dykes.  The  granitic  intrusive  rocks  are  interlaced  in  places  with 
thin  auriferous  gold-quartz  veins.  The  importance  of  Kanowna 
arises  rather  from  its  alluvial  deposits  than  from  its  veins.  The 
alluvial  occurs  as  a  so-called  "  lead,"  which  is  nevertheless  purely 
a  surface  deposit.  The  width  of  the  old  stream-gravel  varies  from 
2  to  80  feet,  with  an  average  of  perhaps  15  feet.  Its  thickness 
ranges  from  a  few  inches  to  90  feet.  The  fall  of  the  bed-rock  is  some 
40  feet  per  mile.  The  deposits  filling  the  old  watercourse  vary  con- 
siderably, but  the  "wash"  itself  is  made  up  of  rounded  and  sub- 
angular  pebbles  of  quartz  cemented  by  secondary  silica  into  a  hard, 
compact  rock.  The  overlying  ;'  pug  '  (kaolin)  and  ironstone 
(lateritic)  gravels  have  also  yielded  minor  quantities  of  gold.  Gold 
is  found  in  the  quartz  pebbles  themselves,  indicating  therefore  a 
derivation  from  the  adjacent  veins,  but  much  gold  occurs  massive, 
arborescent,  or  coarsely  crystalline,  with  clear,  sharply-cut  octahedra, 
the  latter  form  pointing  certainly  to  a  secondary  deposition  from 
solution.  The  average  tenor  of  the  gravel  was  perhaps  an  ounce 
per  ton.  These  secondary  gold  deposits  occur  elsewhere  in  the  State. h 
Bulong  and  Kurnalpi  have,  for  example,  furnished  considerable 
alluvial  gold,  while  their  gold-quartz  veins  have  up  to  the  present 
proved  of  no  great  importance. 

The  most  perfect  crystals  found  in  Western  Australia  were  the 
above-mentioned  single  octahedra  embedded  in  asbolite  (oxide  of 
cobalt  and  manganese)  in  the  Kanowna  pug.  The  largest  crystals 
were,  however,  only  -£$  inch  in  diameter.  Crystallized  gold  has  been 
obtained  also  from  Bulong,  Kalgoorlie,  and  Red  Hill— from  the 
last  in  calcite.  The  largest  alluvial  nugget  yet  found  came  from 
Pilbara,  and  contained  in  gold  41337  ounces  (£1,348).  Its  fineness 
was,  however,  only  768,  and  it,  like  most  West  Australian  nuggets, 
showed  fairly  clear  evidence  of  direct  derivation  from  adjacent 
veins. 


a  Hoover,  Trans.  Amer.  Inst.  M.E.,  XXVIII,   1899,  p.   763. 

h  Maitland,  loc.  cit.  sup.,  1900,  p.  60  ;    Rickard,  T.A.,  Trans.   Amer.  Inst.    M.E., 
XXVin,  1899,  p.  525. 


406 


AUSTRALASIA. 


The  following  are  the  yields  to  end  of  1906  from  the  various 
North-East  Coolgardie  goldfields  :  — 


Fine  Ounces. 

Alluvial. 

Vein. 

Kanovvna 

Bulong 

Kurnalpi 

103,097 
26,046 
10,019 

404,233 

116,721 

6.548 

Dun  das. — The  Dundas  goldfield  lies  south  of  Kalgoorlie. 
Its  chief  camp  is  Norseman,  where  a  small  auriferous  belt  stretches 
north  and  south  for  some  33  miles.  The  rocks  are  similar  to  those 
of  Coolgardie,  being  greenstone-schists  intruded  by  thin  dykes  of 
quartz-porphyry  and  felsite.  These  are  associated  with  the  usual 
banded  and  laminated  haematite-quartzites.  A  considerable  amount 
of  gold  has  been  obtained  from  deep  alluvial  deposits  at  Norseman. 
At  Dundas,  further  south,  a  few  lodes  have  been  spasmodically 
worked.     The  official  returns  to  end  of  1906  were  :  — 


Fine  Ounces. 

Tons  Ore  Crushed. 

Alluvial. 

Vein  Gold. 

1,788 

293,830 

338,264 

Phillips    River. — The  returns    from    Phillips    River  Goldfield 
to  end  of  1906  were  :  — 


Alluvial. 

Vein  Gold. 

Tons  Crushed. 

Ozs. 

286 

Ozs. 

24,268 

29,003 

This  is  the  southernmost  field  of  Western  Australia.  Its  auri- 
ferous veins  he  in  schist  or  in  granite,  or  at  the  contact  between  the 
two.  The  gold  is  largely  associated  with  copper,  and  the  mineral 
wealth  of  the  field  appears  to  lie  in  that  metal  rather  than  in  gold. 

Donnybrook.— The  Donnybrook  is  an  isolated  goldfield  lying 
in  the  extreme  south-east  corner  of  the  State  and  not  on  the 
strike  of  any  of  the  great  auriferous  belts.  Its  veins  traverse 
hornblendic  and  gneissic  granites  near  their  intersection  with  a 
diorite  dyke  that  varies  in  width  from  £  to  1  mile.  The  total 
product  of  the  area  to  date  has,  however,  been  only  840  fine  ounces. 


407 


AFRICA. 


MOROCCO. 


No  gold  mines  are  actively  worked  in  Morocco,  but  alluvial  gold 
in  small  grains  and  flakes  has  occasionally  been  obtained  along  the 
course  of  the  Wadi  Sus,  in  the  Sus  province,  south-west  Morocco. 
At  Idaultit,  in  the  northern  portion  of  the  same  province,  and  at  the 
foot  of  the  Atlas  mountains  copper  ores  have  been  found  carrying 
small  quantities  of  gold.a 

ALGERIA. 

The  gold  occurrences  of  Algeria  are  of  trifling  importance.  The 
pyrite  mines  of  Kef-um-Tabul,  near  La  Calle,  in  the  department 
of  Constantine,  yield  small  quantities  of  gold  on  smelting  the 
chalcopyrite  that  occurs  with  the  pyrite.  The  quantity  thus 
obtained  is  insignificant. &  Another  auriferous  locality  is  reported 
at  Oued-el-Dzeheb,  near  Mila,  west  of  Constantine.0  Vague  rumours 
are  current  in  the  seaboard  towns  of  the  employment  of  large  numbers 
of  natives  in  gold  mines  in  the  Atlas  mountains,  and  from  time  to 
time  gold  is  shown  in  Algiers  that  is  said  to  be  obtained  from  these 
workings. 

TUNIS. 

At  Sidi-Boussaib,  near  the  ruins  of  Carthage,  there  occur  allu- 
vial gravels  that  contain  small  quantities  of  fine  gold.  The  sands 
are  derived  from  Pliocene  sandstones  and  conglomerates  ;  from 
these  the  gold  is  also  probably  derived.  These  placers,  if,  indeed, 
they  were  ever  of  importance,  were  certainly  exhausted  with,  or 
perhaps  even  before,  the  foundation  of  Carthage,  for  the  Second 
Punic  War  (219  B.C.)  was  occasioned  by  the  desire  of  the  Romans 
to  obtain  control  of  the  Spanish  mines,  acknowledged  to  be  the  sole 
source  of  the  enormous  hoards  of  gold,  silver,  and  copper  accumulated 
in  Carthage. 

TRIPOLI. 

No  gold  appears  to  be  produced  within  Tripoli  itself,  but  a  con- 
siderable amount  of  gold-dust  and  melted  gold  has  been  exported 
from  the  country.     The  source  of  this  gold  is  uncertain,  but  the 

a  Futterer,  "  Afrika,  &c,"  Berlin,  1895,  p.  40. 

"  Pelatan,  Les  Richesses  Minerales  des  Colonies  francaises,  Paris,  1902,  p.  107. 

c  MacCarthey,  Geog.  physique,  econ.  et  pol.  de  PAlgerie,  Algier,  1858,  p.  118. 


408  AFRICA. 

greater  part  of  it  has  probably  come  from  Senegambia  and  from 
the  Gold  Coast,  by  caravan  across  the  Sahara  desert  in  the  ordinary 
course  of  trade. 

EGYPT. 

The  auriferous  regions  of  Egypt  lie  on  the  eastern  side  of  the 
Nile,  between  that  river  and  the  Red  Sea.  They  are  grouped  both 
to  the  north  and  to  the  south  of  the  Tropic  of  Cancer,  and  for  the 
most  part  to  the  east  and  south-east  of  Assouan.  They  are  possibly 
among  the  oldest  of  the  world's  goldfields,  for  the  earliest  known 
reference  to  gold  is  contained  in  an  edict  of  Menes  (perhaps  3800  B.C.) 
which  enacted  that  the  ratio  of  the  value  of  silver  to  gold  should 
be  fixed  at  2i  to  1.  An  official  document,  dated  about  2500  B.C., 
relates  how  the  gold  was  escorted  from  mines  between  Keneh  and 
Kosseir  to  Koptos  on  the  Nile.a 

Under  the  19th  dynasty  (1300  B.C.)  numerous  gold  mines  were 
worked  in  the  Wadi  Abbas,  near  Rhedesia,  and  at  Akita  (Wadi 
Allaghi).  The  latter  are  supposed  to  have  been  opened  during  the 
reign  of  Setos  I  (1360  B.C.),  who  caused  wells  to  be  sunk  along  the 
road  to  the  mines,  a  work  that  was  continued  by  his  son,  Rameses 
the  Great.  A  rude  mining  plan,  probably  the  oldest  extant,  of 
certain  of  these  ancient  Egyptian  mines,  was  discovered  by 
Drovetti  at  Thebes,  and  by  him  taken  to  Turin.  The  particular 
mines  represented  on  the  plan  are  believed  to  be  those  of 
Dereheib,  well  known  at  the  present  day. 

The  ancient  mines  are  said  to  have  furnished  a  large  portion 
of  the  revenue  of  the  kings,  and  particularly  of  the  annual  revenue 
of  the  second  Ptolemy,  which  was  estimated  at  14,800  talents, 
or.  more  than  four  millions  sterling.  From  the  ancient  mines  of 
Hamesh  it  is  said  that  several  millions  of  tons  of  quartz  have  been 
extracted.  Near  the  present  Um  Rus  mines  every  reef  and  vein 
over  an  area  of  25  square  miles  has  been  thoroughly  prospected. 

The  first  definite  account  of  the  Egyptian  gold  mines  is  given 
by  Agatharchides  (140  B.C.),  who  paints  a  moving  picture  of  the 
miseries  endured  by  the  unfortunate  wretches  condemned  to  work 
in  the  Egyptian  gold  mines.  The  works  of  Agatharchides  are  lost,  but 
fragments  of  them,  including  fortunately  the  following,  have  been 
preserved  for  us  by  Diodorus  Siculus  and  others.  Of  that  portion 
dealing  with  the  gold  mines  the  subjoined  is  a  free  abstract  :  '  They 
put  fire  to  the  veins,  and  the  stone  thus  loosened  is  carried  away  and 
crushed.  An  expert  miner  performs  the  work  of  tracing  the  vein, 
and  brings  the  labourers  to  those  places,  dividing  the  work  among 
them  according  to  the  capacity  of  the  individual.  The  strongest, 
and  those  still  in  the  prime  of  life,  are  used  to  break  the  stones,  and 


n  Wallis-Budge,  "  The  Egyptian  Sudan,"  London,  1907,  II,  p.  336. 


Pi 
» 

CO 

W 
ft 

la 

«! 

H 

Hh 

o 

o 

3 

GO 

o 
Pi 

6n 
i— » 

PS 

o 

CO 
& 


EGYPT. 


409 


to  work  in  the  shafts.  With  nothing  but  their  own  strength  they 
break  the  stone  with  heavy  iron  hammers,  and  follow  the 
ill-defined  course  of  the  gold-bearing  vein.  A  light  is  fixed  to  their 
foreheads,  and  then,  under  the  eyes  of  their  tyrannical  overseers, 
they  break  the  gold-bearing  stone.  Children  bring  the  broken  stone 
out  from  the  mines  ;  old  men  carry  it  to  those  who  have  to  crush  it, 


Fig.  142.    Ancient  Egyptian  Mining  Map.  _  Supposed  date,  1300  B.C. 

.1  •"  Mountains  in  which  the  Gold  is  washed  they  are  coloured  here  in  red."      II  "  Gold  Mountains." 

C  Large  buildings  and  Temple  to  Ammon.    D   Gold  workers'   houses. 

E  Well,  &c,  E'  Pool  of  water  in  F  Palace  '.'rounds  of  King  Setos  I.    G  Monument  of  the  King. 

//  Wady  leading  to  the  sea.     I  Connecting  Wady.    J  Roadway  to  the  Sea. 

K   Wady  with  numerous  wells  and  trees.    Dotted  lines  indicate  portions  restored. 

Top  of  Map  supposed  to  be  North.  Note. — Contour  lines  supposed  to  indicate  hills  in  elevation. 

a  work  which  is  effected  by  strong  men  of  30  years  of  age,  using  iron 
pestles  in  mortars  hewn  from  the  solid  rock  ;  so  they  reduce  it 
until  the  largest  piece  is  no  bigger  than  a  pea.  The  next  task  is  per- 
formed by  women  at  mills  placed  in  a  line.  Standing  three  together 
at  one  handle,  and  filthy  and  almost  naked,  the  women  work  until  the 
measure  handed  to  them  is  completely  reduced,  and  to  every  one 
of  those  who  bear  this  lot  death  is  better  than  life.  Expert  workmen 
.     .      .     pour  the  powdered  quartz  on  an  inclined  broad  and  polished 


410  AFRICA. 

table  whereon  the  gold  is  washed  and  taken  up  with  sponges.  Finally, 
it  is  transferred  to  melters,  who  melt  it  in  a  clay  pot,  and  in  proportion 
to  its  quantity  they  add  a  lump  of  lead,  grains  of  salt,  a  little  alloy 
of  silver  and  lead  and  barley  bran.  The  mouth  of  the  pot  being 
carefully  covered  and  luted  round,  they  keep  it  fused  five  days  and 
five  nights  consecutively  ;  ...  in  the  end  they  find  none  of 
the  things  that  were  put  in  together,  but  only  a  mass  of  molten 
gold,  but  little  less  than  the  original  matter."" 

Further,  Diodorus  Siculus,  treating  of  the  gold  production  of 
Egypt  about  50  B.C.,  partly  from  information  derived  from  Agath- 
archides,  says  :  '  On  the  borders  of  Egypt  and  the  neighbouring 
countries,  some  districts  contain  many  gold  mines,  producing  quanti- 
ties of  gold.  The  soil  is  black,  but  it  contains  many  veins  white 
as  marble  and  glittering  with  the  precious  metal.  The  Kings  of  Egypt 
condemn  vast  multitudes  to  the  mines  who  are  notorious  criminals, 
prisoners  of  war,  and  persons  convicted  by  false  accusation — 
the  victims  of  resentment.  And  not  only  the  individuals  themselves, 
but  even  whole  families  are  doomed  to  this  labour,  with  the  view  of 
punishing  the  guilty  and  of  profiting  by  their  toil.  The  vast  numbers 
employed  are  bound  in  fetters  and  compelled  to  work  day  and  night 
without  intermission,  and  without  hope  of  escape  ;  for  they  set  over 
them  barbarian  soldiers  who  speak  a  foreign  language,  so  that  there 
is  no  possibility  of  conciliating  them  by  persuasion  or  through 
familiar  intercourse.  No  attention  is  paid  to  their  persons,  they 
have  not  even  a  piece  of  rag  to  cover  themselves  ;  and  so  wretched 
is  their  condition  that  all  who  witness  it  deplore  the  excessive 
misery  they  endure.  No  rest,  no  intermission  from  toil  is  given 
either  to  the  sick  or  maimed  ;  neither  the  weakness  of  age  nor 
woman's  infirmities  are  regarded  ;  all  are  driven  to  their  work  with 
the  lash,  till  at  last,  overcome  with  the  intolerable  weight  of  their 
afflictions,  they  die  in  the  midst  of  their  toil.  So  these  unhappy 
creatures  always  expect  worse  to  come  than  they  endure  at  the 
present,  and  long  for  death  as  preferable  to  life." 

Numerous  ancient  circular  stone  mills,  obviously  for  quartz 
crushing,  still  exist  and  have  been  described  by  various  modern 
writers. b  During  the  internal  and  foreign  disturbances  to  which 
Egypt  was  subjected  in  the  early  centuries  of  the  Christian  era,  the 
gold  mines  appear  to  have  been  almost  entirely  neglected.  In  the 
beginning  of  the  ninth  century  the  notorious  adventurer  Abdur- 
rahman-el-Omari,  a  descendant  of  the  Khalifa,  established  himself 
in  the  neighbourhood  of  the  mines,  and  there  spent  thirty  turbulent 

a  Floyer,  Jour.  Roy.  As.  Soc.  (Lond.),  XXIV,    1892,  p.  825. 

b  Alford,  Trans.  Inst.  Min.  Met.,  X,  1902,  p.  29  ;     Hcrzig,  Mm.  Sci.  Press,  Aug.  17, 
1907  ;    Llewellyn,  "  Mining  Report  on  Egyptian  Soudan,"  London,  1903. 


EGYPT. 


411 


years.  Towards  the  end  of  this  period  he  had  no  less  than  60,000 
camels  carrying  provisions  to  his  miners  from  Assuan,  in  additionjto 
large  wheat  supplies  received  from  Aidab  on  the  Red  Sea.  His 
principal  mines  were  probably  Um  Garaiart,  Gebel  Aswad,  and  Ceiga 
(Saiga),  all  of  which  have  been  extensively  worked.    From  this  time 


Fig.  143.     Geological  Sketch  Map  of  the  Northern'  Atbai  Desert  (Humf). 
1.  Gneiss.    2.  Schist.    3.  Granite.    4.  Nubian  Sandstone  (Cretaceous).    5.  Senonian   Limestone. 

6.  Basalt  and  Younger  Volcanics. 


onward  until  the  beginning  of  the  twentieth  century  the  gold  mines 
of  Eygpt  appear  to  have  been  deserted.  Attention  has  since  1898 
been  directed  towards  the  re-opening  of  the  ancient  gold  mines,  and 
a  considerable  amount  of  capital  has  been  invested  in  prospecting 
work.     The  returns  to  date  are,  however,  far  from   commensurate 


412  AFRICA. 

with  the  high  hopes  entertained  in  the  early  days  of  exploration. 
The  gold-quartz  veins  so  far  worked,  have  proved  to  be  more  patchy 
in  value  and  more  uncertain  in  width  than  was  at  first  expected. 

The  general  geology  of  the  auriferous  region  is  simple.  The 
higher  ranges  are  hornblendic  granite,  containing  a  pink  orthoclase. 
The  lower  flanking  ranges  are  composed  of  a  fine-grained  grey  granite, 
passing  in  places  into  gneiss,  and  that  again  into  mica-schist,  the 
whole  series  being  traversed  by  dykes  and  intrusions  of  diabase, 
diorite,  felsite,  porphyry,  and  a  very  fine-grained  white  elvan- 
granite.a  It  is  in  the  schistose  rocks  or  in  the  basic  gneiss  close  to 
the  schists  that  most  of  the  auriferous  quartz  occurs  and  a  genetic 
relation  between  the  veins  and  the  intrusive  rocks  is  generally 
probable.  The  crystalline  schists  that  occur  in  this  complex  b 
strike  about  N.  60°  W.  and  apparently  overlie  the  gneiss.  Talc- 
and  mica-schists  occur  over  large  areas,  and  furnish  the  famous  beryl 
mines  of  the  northern  district.  In  the  central  desert  are  extensive 
exposures  of  hornblende-schists,  derived  from  original  igneous 
rocks,  but  calcareous  schists  and  graphitic  schists,  representing 
original  sediments,  are  also  present. 

The  Um  Garaiart  auriferous  region  (Nile  Valley  Company)  is 
composed  of  schists  and  slates  broken  by  belts  and  patches  of  diorite, 
granite,  and  syenite,  and,  in  places,  beds  of  dolomitic  limestone.  On 
the  "  Haimur  "  mine  in  this  concession  the  veins  are  all  contained 
in  highly  dolomitised  schists  varying  in  character  from  a  highly 
siliceous  rock  on  the  one  hand  to  a  soft,  white,  dolomitic  and  fels- 
pathic  rock  on  the  other.  Siliceous  bands  form,  by  their  superior 
hardness,  long,  outstanding,  serrated  ridges.  The  schists  are  in 
places  highly  graphitic,  and  often  contain  numerous  cubical  pseudo- 
morphs  of  haematite  after  pyrite.c  It  will  at  once  be  apparent  that 
the  general  geological  description  of  this  country  recalls  very 
strongly  that  of  the  Dharwar  auriferous  region  of  India,  already 
described.  Overlying  the  crystalline  rocks  on  either  side  of  the 
mountains  are  wide  expanses  of  the  Nubian  sandstone,  which  is 
again  overlain,  probably  unconformably,  by  Cretaceous  and  Tertiary 
nummulitic  limestones. 

In  the  northern  portion  of  the  Atbai  desert  the  known  ancient 
workings  are  Wadi  Hammama,  where  the  gold-quartz  veins  occur  in 
the  "greenstone,"  and  Eridia,  where  there  are  numerous  veins  from 
mere  .threads  up  to  30  inches  in  width.  At  Eridia  are  also  extensive 
ruins  of  an  ancient  mining  town.     The  veins  occur  either  in  a  grey 

n  Alford,  "  Report  on  Gold  Mining  in  Egypt,"  London,  March,  1900,  p.  5. 

b  MacAlister,    Geog.  Jour.,    XVI,  1900,  p.  543  ;   Hume,  Rep.  Surv.  Dept.,  Egypt. 
No.   1,   1907,  p.  34. 

f  Sleesnan,  Min.  Jour.,  May  20,   1905,  p.  550. 


Plati    XVI. 


Ancient  Egyptian  Quartz-crttshing  Mills,  Xabi  and  Khabaseit. 


EGYPT.  413 

granite  or  at  the  junction  between  an  intrusive  greenstone  (diorite) 
and  the  granite.  The  ancients  appear  to  have  followed  the  wider 
ore-shoots.  At  Fatira,  further  north,  the  ancient  workings  occur  in  a 
granite  country  intruded  both  by  basic  and  by  acidic  dykes,  the 
veins  occurring  indifferently  in  or  between  any  of  the  rock  species. 
The  veins  of  Safaga  nearer  the  coast  lie  also  between  granite  and 
diorite.  The  Jebel  Jasus  mines  on  the  coast  north  of  Kosseir  appear 
to  have  been  worked  primarily  for  lead  and  silver,  but  their  galena 
veins  also  carry  small  quantities  of  gold. 

The  Urn  Esh  workings  south  of  Eridia,  extend  along  a  single 
vein  in  the  granite.  The  wider  portions  have  been  completely  stoped 
out.  The  Fowakhir  group  of  ancient  workings  are  also  in  a  granite 
that  is  largely  intruded  by  basic  dykes.  The  dykes,  however, 
appear  to  be  subsequent  in  age  to  the  veins. 

Debach  is  another  ancient  mining  centre  100  miles  east-south- 
east of  Luxor.  It  possesses  a  large  vein  6  to  8  feet  wide  in  places, 
and  assaying  from  5  to  16|  dwts.  It,  like  the  Fowakhir  veins, 
traverses  a  grey  granite. 

Um  Rus  has  of  late  years  received  considerable  attention.  It 
lies  on  the  coast  of  the  Red  Sea,  about  8  miles  from  Imbarak  Inlet. 
The  old  mines  extend  for  some  distance  westward  into  the  hills,  but 
the  principal  workings  are  in  the  granite  escarpments  facing  the 
sea.  The  gold-quartz  veins  are  white,  and  vary  from  a  few  inches 
up  to  4  feet  in  width.  The  country  is  grey  granite,  with  numerous 
intrusions  of  white  elvan-granite,  felsite,  felsite-porphyry,  and 
greenstone.  Other  ancient  workings  south-west  of  the  Rus  are 
Umtoot  and  Hamesh.  In  both  cases  the  rock  is  grey  granite,  with 
numerous  basic  intrusions. 

The  Betaan  and  Um  Eleagha  ancient  mines  are  25  to  30  miles 
south-west  of  Berenice  on  the  Red  Sea.  Here,  unlike  most  of  the 
foregoing  occurrences,  the  gold-quartz  veins  occur  in  a  greenstone 
(diorite)  that  is  intrusive  into  grey  hornblendic  granite.  The  veins 
are  6  to  30  inches  in  thickness. a 

Still  further  south-west  are  the  vast  ancient  workings  of  Dera- 
heib  on  the  upper  course  of  the  Wadi  Allaghi.  These  mines,  as 
already  observed,  are  believed  to  have  been  worked  by  the  Copts  in 
1300  B.C.  Here  numerous  branches  and  veins  of  the  main  lode  have 
been  carefully  followed  up  by  the  ancients.  Prospecting  operations 
on  these  veins  during  1907  showed  an  average  width  for  the  principal 
lode  of  nearly  5  feet,  but  its  grade  was  too  low  to  admit  of  profitable 
working. 

Two  days  south  of  Deraheib  are  the  Oneib  mines,  where  the 
largest  ancient  workings  in  the  Sudan  or  Egypt  occur.     The  reef 

a  Alford,  !oc.  cit.  sup. 


414  AFRICA. 

occurs  here  in  a  range  of  four  slate  hills,  and  the  stone  has  been 
removed  down  to  the  level  of  the  wadi.  The  crushing  mills  of 
Oneib  appear  to  have  been  located  at  the  nearest  available  water, 
viz.,  El  Harr,  half  a  day's  journey  to  the  north.  These  veins  have 
also  been  found  too  poor  to  be  worked  by  modern  methods. 

North  of  the  Wadi  Allaghi  and  east  of  the  Um  Garaiart  mines 
are  the  Ceiga  (Saiga)  mines  in  mica-  and  talc-schists.  They  were 
probably  worked  by  Abdur-rahman-el-Omari.  The  Um  Garaiart 
mines  of  the  Nile  Valley  Company  are  near  the  Wadi  Allaghi, 
about  50  miles  east  of  the  Nile.a  Its  "  Haimur  '  section  is 
8  miles  north  of  Um  Garaiart.  Here  mineralisation  has  taken 
place  along  shear  planes  in  dolomitic  and  talcose  schists.  Quartz 
is  the  principal  gangue,  but  calcite  and  dolomite  also  occur. 
The  sulphides  present  are  pyrite,  mispickel,  and  chalcopyrite. 
Graphite  accompanies  the  vein  matter,  especially  where  the  latter 
is  auriferous.  The  coarsest  gold  has  always  been  found  beside  the 
graphitic  matter.6  Occasionally  very  high-grade  gold-quartz  has 
been  met  with.  From  12  tons  obtained  in  prospecting  operations 
about  £2,800  of  gold  was  received. 

The  Um  Garaiart,  Um  Rus,  Eridia,  Attola,  Haimur,  and  Nile 
Valley  Block  E  mines  have  been  actively  developed.  Those  of 
Um  Garaiart,  Um  Rus,  and  Om  Nabardi  are  the  most  important. 
At  Um  Rus  crushing  for  gold  commenced  on  March  6th,  1905. 
The  total  returns  of  gold  from  the  Nile  Valley  and  Um  Rus  com- 
panies amounted  to  £41,000  in  1905.  The  largest  output  to  1907 
has  been  from  a  shoot  of  the  Nile  Valley  Company,  which  produced 
about  £100,000,  all  of  which  went  back  into  the  mine.  No  Egyptian 
mine  has  as  yet  paid  a  dividend,  and  many  of  the  concessions  taken 
up  about  1900  and  1901  have  now  been  abandoned.  Of  those  that 
remain  the  Om  Nabardi  mines  appear  to  offer  the  most  promise. 
These  are  among  the  most  southerly  in  the  Atbai  region,  being 
situated  in  N.  Lat.  21°  05'.  Prospecting  shafts  had  reached  in  1907 
a  depth  of  360  feet,  and  a  10-stamp  mill  was  being  erected.  In 
1905  the  total  value  of  the  gold  obtained  from  Egypt  was  £41,000  ; 
in  1906  the  yield  fell  to  £23,860. 


BRITISH  SUDAN. 

Auriferous  alluvial  gravels  occur  in  the  south  of  Kordofan, 
especially  at  Tira.  The  gold  is  believed  to  be  derived  from 
the  schists  and  ancient  crystalline  rocks  of  the  region.     The  gold 

a  Schweinfurth.  "  Die  Wiederaufnahme  des  Alten  Goldminen  Betriebs  in  Aegypten 
und  Nubien,"  Vossische  Zeitung,  Berlin,  November  22,  1903. 

"  Sleeman,  loc.  cit.  sup. 


BRITISH     SUDAN.  415 

occurrences  are  unimportant.  The  crystalline  rocks  appear  to  run 
north-east  from  Tira  to  Tagalla.  The  source  of  the  gold  is  doubtless 
those  veins  in  the  crystalline  schists  described  by  Russegger"  as 
containing  galena,  pyrite,  magnetite,  mispickel,  &c.  Since  his 
journey  (1837)  no  material  addition  has  been  made  to  our  knowledge 
of  these  deposits. 


ERITREA. 

In  the  Italian  colony  of  Eritrea  gold-quartz  veins  have  been 
worked,  or  rather  prospected,  for  some  years,  but  without  very 
successful  results.  The  rocks  are  metamorphic  schists  similar  to 
those  of  the  Atbai  region  of  Egypt.  The  principal  mines  are  at 
Sciummegale,  Madrizen,  Seroa,  and  Barentu.  The  production  of 
these  mines  for  1907  was  about  3,215  ounces  (100  kg.).  Small  and 
unimportant  placer  deposits  are  also  known. 


ABYSSINIA. 


The  gold  said  to  come  from  Abyssinia  is  really  derived  from  the 
Shankala  and  Beni-Shangal  districts  to  the  west  of  and  beyond  the 
true  Abyssinian  boundary,  but  nevertheless  within  a  region  probably 
recognised  as  being  within  the  Abyssinian  sphere  of  influence. 
These  gold  washings  are  best  described  by  Russegger^  and  by 
Blundell.0  The  latter  shows  that  the  important  washings  commence 
at  the  junction  of  the  Didesa  with  the  Abai  (Blue  Nile),  and  con- 
tinue down  the  Blue  Nile  and  up  the  bed  of  the  Dabus  and  its  tribu- 
taries. These  regions  lie  immediately  to  the  south  of  Fazokl  on  the 
Blue  Nile.  The  gneissic  and  hornblendic  schists  of  the  region  have 
been  so  far  denuded  that  a  large  tract  of  country  is  strewn  with 
quartz  pebbles  and  boulders,  and  numerous  quartz  outcrops  occur. 
The  amount  of  gold  dust  exported  ia  estimated  at  £80,000  a 
year.  The  Dabus,  with  its  affluents,  is  washed  for  something  like 
40  miles  of  its  course,  but  in  1904  the  greater  number  of  washers 
(about  2,000)  were  employed  in  the  lower  20  miles,  nearest  the  Abai. 
This  region,  and  that  of  Beni-Shangal,  is  estimated  to  furnish  about 
three-fourths  of  the  total  quantity  of  Abyssinian  gold.  The  Tumat, 
another  tributary  of  the  Abai,  but  further  north,  furnishes  also  a 
considerable  quantity  of  placer  gold.  The  general  conditions  indi- 
cated by  the  descriptions  of  these  rivers  denote  the  possible  existence 

a  Russegger,  "  Reisen  in  Europa,  Asien  und  Afrika,  etc.,  in  den  Jahren    1835    bis 
1841,"   IV,  p.   203,  Stuttgart,   1844. 

"  Loc.  cit.  sup. 

cGeog.  Jour.,  XXVII,  1906,  p.  544. 


416  AFRICA. 

of  remunerative  dredging  ground.  Much  of  the  gold  obtained  here 
is  exported  from  Abyssinia  by  way  of  Harar  and  Addis- Abbaba. 
In  1905-6  the  amount  thus  exported  was  estimated  at  4,000  ounces, 
of  a  value  of  £15,600.  , 

ITALIAN    SOMALILAND. 

The  country  adjoining  the  Nogal  river,  flowing  west  from 
British  Somaliland,  through  Italian  Somaliland,  has  been  believed 
by  Kosmas  and  by  Glaser"  to  be  the  ancient  auriferous  land  of 
Punt  and  Sasu .  Recent  expeditions,  as  those  of  Bricchetti-Robecchi, b 
however,  make  no  reference  to  modern  gold-washings,  or  even  to 
gold-occurrences.  The  probability  of  their  existence  is  therefore 
remote. 

BRITISH    SOMALILAND. 

The  ranges  of  the  Somali  hinterland  are  Archaean  gneisses, 
schists,  and  granites,  but  notwithstanding  their  resemblance  to 
those  of  Egypt,  they  do  not,  so  far  as  is  yet  known,  furnish  auriferous 
deposits. 

FRENCH  GUINEA. 

Bambuk. — The  auriferous  district  of  Bambuk  lies  between 
the  Faleme  and  the  great  Senegal  rivers,  and  south  of  Kayes  on  the 
latter  river.  The  valley  of  the  Faleme  is  especially  rich,  and 
numerous  ancient  goldfields  are  scattered  through  the  region  con- 
tained between  the  two  rivers.  Gold  occurs  not  only  in  the  gravels 
of  the  rivers  and  valleys,  but  also  in  highly  ferruginous  (lateritic) 
conglomerate  beds  at  a  considerable  depth  below  the  surface. 
These  deposits  are  worked  exclusively  by  the  natives, 
who  dig  pits  of  18  to  20  feet  to  the  pay -gravel,  which  is 
generally  ferruginous,  and  is  occasionally  so  indurated  that 
it  must  be  crushed  before  washing.  The  richest  mines  of 
the  Bambuk  district  are  at  Sola,  Tambaura,  and  Mouralia. 
The  ynassij  of  the  Khakidian,  the  mountain  range  between  the 
Senegal  and  the  Faleme,  is  composed,  according  to  Arsandaux,c  of 
mica-schists  and  quartzite,  with  diabase  intrusives  and  andesitic 
flows  and  tuffs,  all  of  which  appear  to  have  been  metamorphosed, 
the  original  basic  tuffs  now  forming  amphibolite  schists.  The  com- 
plex has  been  intruded  by  later  granite  and  microgranite.  In  the 
neighbourhood  of  the  Keneiba  gold  mines  the  rocks  are  highly 
schistose.  The  amphibolitic  schists  are  charged  with  pyrites,  and 
in  their  neighbourhood,   and    there  only,   the  microgranites  also 

a  "  Die  Goldlander  Punt  und  Sasu  in  Somali-Lande,"  Das  Ausland,  1890,  pp.  521-528. 
b  Boll,  della  Soc.  Geog.  Ital.,  Rome,  1891. 
cBull.  Soc.  franc.  Miner.  XXVII,  1904,  p.  82. 


FRENCH     GUINEA.  417 

contain  pyrite.  These  are  the  two  auriferous  rocks,  and  the  gold  that 
they  furnish  comes  entirely  from  the  pyrites.  The  pay-streaks 
in  the  resulting  gravels  are  always  highly  ferruginous,  and  are 
formed  under  the  conglomerate  ;  the  boulders  forming  the  con- 
glomerates always  show  evidence  of  intense  metamorphism ;  they 
are  invariably  microgranites  associated  with  basic  rocks,  one  at 
least  of  these  two  rocks  being  always  heavily  charged  with  pyrites. 
Concentrated  pyrite  from  the  microgranite  has  assayed  as  high  as 
2f  ounces  per  metric  ton  (85  grammes  per  tonne). 

At  Yatella,  where  the  native  workings  have  long  been  aban- 
doned, the  pay-streak  was  also  in  a  ferruginous  deposit,  derived 
from  an  uralitised  ophitic  gabbro,  which  contains,  however,  no 
pyrites.  At  Sadiola,  perhaps  the  most  important  of  the  old 
placer  workings,  the  tenor  of  gold  is  not  constant  throughout  the 
whole  deposit,  but  increases  gradually  in  depth  until  it  reaches  the 
permanent  water-level  of  the  country.  Arsandaux,  apparently 
with  justice,  concludes  that  the  increase  in  value  denotes  the  develop- 
ment of  a  zone  of  secondary  enrichment  at  the  water  level. 

The  Bambuk  regions  were  worked  by  or  for  the  Portuguese 
as  early  as  1698,  in  which  year  Fort  Galam  was  established.  In 
1714,  Fort  St.  Pierre  was  built  on  the  Faleme  river,  where  gold  had, 
however,  been  discovered  by  a  French  expedition  forty  years  before. 
The  French  and  Portuguese  workings  ceased  with  the  conquest  of 
Senegal  by  the  English  in  1758  ;  from  that  year  to  1779  little  is 
known  of  the  auriferous  history  of  the  region.  In  1784  the  Senegal 
gold  yield  was  531  lbs.  The  famous  traveller,  Mungo  Park  (1795- 
1797),  describes  the  African  methods  of  washing  as  practised  in  these 
regions. 

The  principal  mines  in  1880  were  : — a 

(a)  Kamanan  mines.  These  are  distributed  along  the  Faleme 
river,  mainly  in  ferruginous  clay,  sand,  and  conglomerate, 

(6)  Tambaura  mines.  The  centre  of  this  region  is  Sola. 
Numerous  shafts  are  here  sunk  about  4Q  feet  to  water  level.  The 
gold-bearing  bed  lies  from  20  to  40  feet  below  the  surface,  and  is  a 
yellow-spotted  argillaceous  bed  with  grains  of  iron-ore.  The  gold 
is  not  always  fine,  but  often  occurs  in  nuggets  up  to  1  to  2  dwts. 
in  weight. 

(c)  Niagalla  mines.  These  are  principally  in  the  neighbour- 
hood of  Sadiola,  15  miles  south-east  of  Kenieba  (Long.  10°  W.,  Lat. 
11°  N.).  The  district  of  Bure  on  the  left  bank  (Tankisso  tributary) 
of  the  Joliba  or  Niger  river,  contains  auriferous  deposits  very  like 
those  of  Labi,  further  west.  They  have  for  long  been  worked  by 
the  natives  of  the  country.     The  workings  lie  on  the  slopes  of  the 

a  Lamartiny,  Bull.  Soc.  Geog.  Commer.  Paris,  VI,  1883,  p.  28. 
CI 


418  AFRICA. 

hills.     In  1886  their  produce  was  estimated  by  Le  Brun-Renauda  at 
£20,000. 

Labi. — The  Labi  (Futa-Jallon)  auriferous  area,  is  situated  in 
the  mountains  in  the  heart  of  the  Futa-Jallon  district.  Gold  occurs 
there  in  the  alluvial  gravel  of  Dioula,  Tiolo,  Bago,  Kambara,  Dango, 
&c.6  In  1904  gold  to  the  value  of  £27,499,  and  in  1905  £24,088,  was 
exported,  mostly  from  the  Faleme  river. 

The  most  recent  information  on  this  region  is  furnished  by 
Desplagnes,c  who  describes  with  some  detail  the  auriferous  deposits 
of  the  headwaters  of  the  Bakoy  river,  one  of  the  upper  streams  of  the 
Senegal.  Gold-mining  is  here  of  great  antiquity  and  numerous 
shafts  40  to  60  feet  in  depth  have  been  sunk  through  the  overlying 
laterite  and  sands  to  reach  the  pay-gravels  that  lie  on  a  bed-rock 
for  the  most  part  of  diabase  or  diabase-schist.  The  pay-streak 
generally  lies  below  a  well-cemented  auriferous  and  ferruginous 
conglomerate.  The  chief  localities  now  worked  by  the  native 
miners  are  at  Bure  and  Sieke  in  the  country  between  the  Tankisso 
and  the  Niger.  During  the  dry  season  hundreds  of  natives  find 
employment  in  extracting  and  crushing  the  conglomerate.  There 
are  not  here,  as  on  the  Faleme,  any  auriferous  sands  or  gravels  that 
yield  their  gold  on  simple  washing.  The  whole  of  the  pay-gravel  is 
so  thoroughly  cemented  that  preliminary  crushing  is  necessary.  The 
auriferous  conglomerates  have  been  traced  over  an  area  of  3 1  square 
miles  (80  sq.  km.).  From  this  region  much  of  the  gold  of  Guinea 
and  the  Soudan  has  been  derived. 

Remote  though  these  regions  are,  they  are  already  being  ex- 
ploited by  French  enterprise.  Two  dredges,  treating  1,200  and 
1,500  tons  gravel  daily,  are  at  work  on  the  Tankisso  river.  The 
average  tenor  of  the  gravels  treated  is  reported  at  12  to  20  grains 
per  metric  ton.^ 

LIBERIA. 

Gold  in  unimportant  quantity  as  fine  water-worn  grains  is 
reported  from  the  sands  of  the  Sinoe  river  in  the  south-east  of 
Liberia.e 


FRENCH    IVORY    COAST. 

The  auriferous  districts  of  Baule  and  Indenie  both  lie  in  the 
hinterland  of  the  French  Ivory  Coast  well  beyond  the  dense 
tropical   forest  zone  that  separates  them    from    the    coast.      The 

a  "  Les  possessions  fran9aises  de  l'Afrique  occidentale,"  Paris,  1884. 

'J  Pelatan,  "  Les  Richesses  Minerales  des  Colonies  francaises,"  Paris,  1902,  p.  142. 

c  Bull.  Soc.  Geog.,  Paris,  XVI,  1907,  p.  225. 

d  Loc.  cit.,  p.  235. 

e  Buttikofer,   "  P«eisebilder  aus  Liberia,"   II,    Leyden,    1890. 


FRENCH  IVORY   COAST.  419 

auriferous  country  is  a  continuation  of  that  of  the  Wassau  mines 
in  the  neighbouring  Gold  Coast  Colony.  It  is,  therefore,  restricted 
mainly  to  the  eastern  portion  of  the  Ivory  Coast,  but  it  crosses  the 
Indenie  district  and  the  Komoe  river,  and  reaches  west  to  Baule, 
which  is  situated  between  the  Sini  and  the  White  Rendama  rivers. 
Auriferous  alluvial  gravels  are  less  developed  here  than  in  the  Bure 
and  Bambuk  districts  already  described,  but  on  the  other  hand  gold- 
quartz  veins  are  numerous,  and  some  show  free  gold  at  their  outcrops. 
The  principal  mines  of  Indenie  (the  district  between  the  Gold  Coast 
frontier  and  the  Komoe  river)  are  at  Saranu  and  Assikasso,  situated 
about  200  miles  from  and  north  of  the  coast.  The  country  is  Archaean 
rock  (granite,  diorite,  gneiss,  and  basic  crystalline  schist),  all  more 
or  less  covered  by  the  thick  lateritic  deposits  characteristic  of  well- 
watered  tropical  regions. 

The  gold  occurs  :  {a)  As  reef  gold  in  the  schists  ;  (b)  as  detrital 
gold  in  the  laterite  ;  and  (c)  as  alluvial  gold  in  the  streams.  The  reef 
gold  is  the  source  of  the  other  two.  The  general  strike  of  reefs  on 
the  Ivory  Coast,  as  in  the  neighbouring  Gold  Coast  Colony,  is  north 
of  east.  The  quartz-reefs  are  white  and  opaque,  and  carry  pyrite, 
chalcopyrite,  and  galena.  The  largest  native  workings  are  near 
Koffikouro,  in  Lower  Sanwi,  where  two  shafts  40  feet  deep  had  been 
sunk.  Numerous  old  workings  are  also  found  at  Akrizi  and  Dadieso, 
in  the  Sanwi  district.  The  lateritic  formation  has  been  worked  at 
Afrenu,  Lower  Sanwi,  and  at  Beboum,  near  Saranu,  mainly  by 
bell-pits  15  to  20  feet  deep.  The  gold  is  fairly  coarse,  and  nuggets 
of  3  to  4  dwts.  each  are  not  uncommon.61  In  the  Baule  district,  the 
Kokombo  is  an  important  mine.  It  was  worked  originally  by  the 
natives  who  had  sunk  shafts  on  each  vein  to  depths  of  60  to  100  feet. 
The  ore  was  raised  by  liana  ropes,  crushed  fine  on  rocks,  and  washed 
in  bateasP 

In  1904  the  gold  industry  was  progressing  favourably,  particu- 
larly in  the  Sanwi  and  Indenie  districts.  The  gold  obtained  and 
exported  in  1905  was  707  ounces  (22  kg.),  of  a  value  of  £2,664 
(66,000  fr.).  One  hundred  and  fifty-four  men  were  being  employed 
at  the  Akrizi  mine  in  the  Sanwi  district.  This  mine  is  notable  since 
the  quartz  carries  free  gold  associated  with  tellurides. 

Armas c  found  near  Aloso,  in  the  Sanwi  district,  gold  associated 
with  the  quartz  lenses  of  a  gneiss  rock,  and  also  in  schists  penetrated 
by  granites.  Chaper^  notes  the  existence  of  auriferous  clays  imme- 
diately to  the  east  and  north  of  the  Aby  Lagoon,  near  the  coastal 

a  Truscott  and  Samwell,  Trans.  Inst.  Min.  Met.,  XII,  1903,  p.  161. 

"  Pelatan,  loc.   cit.   sup.,  p.    144. 

c  Ann.  des  Mines,  II,  Ser.  10,  1902,  p.  472. 

d  Bull.  Soc.  Geol.  de  France,  XIV,  Ser.  Ill,  1886,  p.  112. 


420 


AFRICA. 


town  of  Assinic.     As  might  be  expected  from  its  occurrence  in  clay, 
the  gold  was  very  fine,  and  the  deposit  poor. 

GOLD  COAST. 

The  auriferous  wealth  of  the  Gold  Coast  appears  to  have  first 
been  made  known  to  the  Western  European  nations  as  a  result  of  a 
French  exploring  and  trading  expedition  in  1382  a.d.  The  French 
station  then  founded  was  abandoned  in  1413.  In  1471,  a  Portuguese 
expedition  established  the  present  Elmina  ( "  Oro  de  la  Mina").  The 
first  English  expedition  to  the  new  source  of  gold  was  made  in 
1551.  Its  ships  returned  to  England  with  150  lbs.  of  gold-dust, 
much  pepper,  and  other  West  African  products.  The  first  English 
gold-mining  company  to  operate  in  the  region  was  one  formed  in 
1825,  the  outcome  probably  of  the  wide-spread  desire  to  seek  for 
gold  that  at  that  time  found  expression  in  the  formation  of  so 
many  South  and  Central  American  mining  companies.  It  is  esti- 
mated that  the  annual  export  of  gold-dust  from  the  coast  in  the 
early  years  of  the  nineteenth  century  was  from  £360,000  to  £400,000 
per  annum.  Modern  mining  dates  from  about  1880,  when  9,129 
ounces  of  a  value  of  £32,865  were  produced,  but  prospecting  opera- 
tions have  been  conducted  on  a  large  scale  only  since  1898,  and  the 
output  assumed  considerable  proportions  as  a  result  of  vigorous 
development  only  in  1903. 

The  following  table  shows  the  output  of  the  Gold  Coast  Colony 
and  Ashanti  for  the  past  21  years  : — 


VpQ  *• 

Weight. 

Value. 

J.  KOiL  , 

Crude  Ounces. 

Sterling. 

1887 

22,546 

£81,168 

1888 

24,030 

86,510 

1889 

28,666 

103,200 

1890 

25,460 

91,657 

1891 

24,475 

88,112 

1892 

27,446 

98,806 

1893 

21,972 

79,099 

1894 

21,332 

76,796 

1895 

25,415 

91,497 

1896 

23,940 

86,186 

1897 

23,555 

84,797 

1898 

17,733 

63,837 

1899 

14,250 

51,300 

1900 

10,557 

38,007 

1901 

6,162 

22,187 

1902 

26,911 

96,880 

1903 

70,775 

254,790 

1904 

93,548 

345,608 

1905 

168,457 

657,330 

1906 

225,959 

877,568 

1907 

293,218 

1,163,517 

GOLD    COAST.  421 

Owing  to  the  dense  jungle  and  to  the  general  conditions  obtaining 
in  the  colony,  geological  surveying  is  exceedingly  difficult,  and 
little  information  under  this  head  is  available.  The  reefs  of 
the  Tarkwa  district,  situated  about  40  miles  from  Sekondi  on 
the  coast,  are  conglomerate-beds  occurring  in  a  series  of  sand- 
stones and  quartzites.  The  last  at  times  are  so  coarse  as  to 
become  grits.  Beds  of  dolomite  are  interst ratified  with  the  quartzite. 
Overlying  and  conformable  with  the  quartzites  are  arenaceous  clay- 
slates  containing  a  few  thin  fine-grained  sandstone  beds.  These  two 
series  make  up  the  country  of  the  goldfield.  The  surrounding 
formations  are  basic  igneous  rocks,  and  schists  and  slates  derived 
from  them  ;  these  rocks  contain  white,  slightly  auriferous  quartz  reefs. 
The  strata  of  the  field  are  disposed  as  a  long,  perfect  syncline,  south- 
west of  Tarkwa,  and  there  is  no  doubt  that  the  Tamsoo  and 
Teberibi  conglomerate  reefs  on  opposite  sides  of  the  syncline  are  one 
and  the  same  vein.a  The  pebbles  of  the  auriferous  conglomerate 
vary  in  size,  and  may  attain  4  inches  in  diameter.  They  consist  of 
dull-white  quartz.  The  matrix  is  a  white  micaceous  sandstone, 
with  occasional  deep  green  stains.  At  Cinnamon  Bippo,  to  the  west- 
north-west,  large  patches  of  talc  occur  in  the  reefs.  At  Busanshi, 
still  further  west,  the  pebbles  are  larger,  reaching  8  inches  in  length. 

At  the  Teberibi  mine,  on  the  opposite  side  of  the  syncline  from 
Tarkwa,  two  reefs  occur.  The  dip  of  the  country  and  of  these  reefs 
is  about  35°  south-east.  The  principal  conglomerate  reef  is  about 
50  feet  thick,  and  contains  occasional  bands  and  wedges  of  sand- 
stone. Several  well-defined  conglomerate  bands  occur  in  it.  The 
pebbles  vary  in  size  up  to  3  inches.  They  consist  of  white  translu- 
cent and  sugary  quartz.  The  matrix  consists  of  schistose 
white  and  pink  micaceous  sandstone.  The  second  reef  is  5  feet 
thick  ;  little  is  known  about  it.  At  Mantraim  the  reef  dips  at  a 
very  low  angle  (8°).  It  is  composed  of  blocks  of  rough  conglomerate 
with  large  white  quartz  pebbles,  some  dark  indurated  slate  pebbles 
not  much  rounded,  and  numerous  wedges  of  sandstone.  The 
Detchikroom  reefs  dip  65°  S.  The  country  is  white  micaceous 
sandstone,  with  auriferous  conglomerate  bands. 

The  enclosing  country  when  examined  from  near  the  surface 
is  a  sandstone  composed  of  quartz  grains,  white  mica,  and  iron 
oxide.  It  becomes  schistose  at  the  ends  of  the  Tarkwa  syncline. 
Near  the  surface  the  pebbles  of  the  conglomerate  are  invariably 
coated  with  white  mica.  They  are  mostly  white  quartz,  but  darker 
quartz  and,  occasionally,  slate  pebbles  also  occur.  The  quartz 
pebbles  of  the  conglomerates  are  cemented  by  a  fine-grained  mixture 
of  granular  quartz,  white  mica,  and  granular  haematite.     Banded 


°  Sawyer,  Trans.  Inst.  Min.  Eng.,  XXII,  1902,  p.  402  ;   Id.,  XXIII,  1903,  p.  527. 


422  AFRICA. 

quartzites  are  found  consisting  of  alternating  bands  of  quartz  and 
iron  oxide. 

The  Tarkwa  conglomerate  pebbles  occasionally  contain  gold. 
The  greater  portion  of  the  gold,  however,  occurs  in  the  matrix. 
The  conglomerate  beds  usually  contain  more  gold  nearest  the  foot- 
wall,  but  the  hanging-wall  is  occasionally  worth  working.  No  pyrites 
had  up  to  1903  been  met  with  in  the  auriferous  conglomerate." 

The  dykes  of  the  field  are  mainly  basic  igneous  rocks  (dolerites 
and  diabases),  forming  either  sheets  or  dykes.  They  are  of  frequent 
occurrence.  Hornblende-diabase  occurs  in  great  abundance  at 
Aquapim  and  Periperi,  midway  between  Tarkwa  and  Prestea,  and 
elsewhere  in  the  vicinity  of  Busumchi.  Diorite  and  andesite  (por- 
phyrite)  also  occur,  mainly  to  the  south  of  Tarkwa.  Typical 
hornblende-biotite-gneiss  occurs  on  the  coast  near  Sekondi,  but 
nothing  of  the  sort  was  seen  near  Tarkwa.  At  Prestea,  to  the 
north-east,  graphitic  schists  occur,  and  Sawyer  mentions  having 
seen  rich  gold-quartz  from  near  Kumasi  in  Ashanti,  where  it  was 
contained  in  graphitic  schist. 

The  principal  quartz  mines  of  the  Gold  Coast  Colony  and 
Ashanti,  with  their  yields  for  1907  in  ounces  are  :  Prestea  Block  A 
(40,393),  Ashanti  Goldfields  (35,065),  Abbontiakoon  Block  I  (22,843), 
Wassau  (21,338),  Abosso  (20,692),  Bibiani  (19,140),  Broomassie 
(15,867),  and  Akrokerri  (10,716).  Four  mines,  viz.,  the  Abbontia- 
koon Block  I,  Wassau,  Obosso,  and  Taquah  and  Abosso,  are  working 
the  above-described  auriferous  conglomerate  and  produce  about  34 
per  cent,  of  the  total  gold  produce  of  the  colony.6  The  other  mines 
are  working  on  fissure- veins  of  the  normal  type.  At  the  Abosso 
mine  the  ore  crushed  in  1907  had  an  average  tenor  of  £3  per  ton, 
while  the  costs  were  of  necessity  high,  varying  from  33s.  to  38s. 
The  average  yield  at  the  Wassau  mine  was  44s.  7-  65d.,  while  the 
costs  were  32s.  7-  14d. 

A  considerable  amount  of  gold  is  recovered  by  dredging.  The 
principal  dredging  rivers  are  the  Omn,  Ankobra,  and  Birrim,  on 
all  of  which  dredges  have  been  at  work.  The  following  are  the 
yields  obtained  by  dredging  from  1905  to  1907  : — 

Ounces  Gold. 

1905        12,707 

1006         15,154 

1007         10,650 


a  Sawyer,  loc.  cit.  sup. 

b  Wilkinson,  W.  F  ,  Eng.  Min.  Jour.,  Jan.  4,  1908,  p.  57. 


423 

TOGOLAND. 

In  the  gneissic  zones  in  crystalline  schists  near  Towega  veinlets 
of  chalcedonic  quartz  occur,  carrying  about  2  grains  gold  per  ton. 
This  is  the  only  auriferous  occurrence  in  Togoland/' 


CAMEROONS  (KAMERUN). 

The  gneiss  and  mica-schists  in  the  neighbourhood  of  Edea 
Station  (Lower  Sannaga  River)  carry  gold.  Aboland,  immediately 
to  the  north  of  Kamerun  and  the  Kamerun  river,  contains  unimpor- 
tant gold  and  silver  veins.6 


FRENCH  CONGO. 

In  the  south  of  the  colony,  not  far  from  the  coast,  and  near  the 
village  of  Mayumba,  a  granite  islet  carries  an  outcrop  of  gold-quartz 
which  has  not,  however,  been  exploited. 


ANGOLA. 

To  the  east  of  St.  Paul  de  Loanda  is  situated  the  auriferous 
district  of  Golungo  Alto.c  North  of  the  town  of  that  name,  on  the 
Lombige  river,  an  expedition  headed  byMonteiro,  washed  for  several 
months  for  a  return  of  only  a  couple  of  pounds  of  gold.  The  gold 
was  938-6  fine.  According  to  Cho£fatd  mica-schists  occur  in  the 
neighbourhood. 

Cuninghamee  reports  an  auriferous  conglomerate  east  of  the 
Kunene  river  {circa  S.  Lat.  13°  20';  E.  Long.  16°).  Gold-washings 
have  long  been  known  to  exist  somewhat  north  of  this  spot  in  the 
Bailundu  district.  The  rocks  of  the  region  are  apparently  schists./ 
The  sands  of  the  upper  waters  of  the  Kunene  river  are  washed  for 
gold,  and  have  been  said  to  have  yielded  good  returns  to  a 
Brazilian  miner,  who  had  worked  there  for  many  years.  Somewhat 
east  of  this  region,  and  on  the  headwaters  of  the  Kasai  branch  of 
the  Congo  and  the  Zambesi,  gold  has  been  washed  by  the  natives. 

A  small  goldfield  is  reported  to  occur  at  Kassinga  in  the  upper 
valley  of  the  Chitanda  river,  which  joins  the  Kunene  at  Kiteve. 

a  Schmeisser,  Zeit.  fur  prakt.  Geol.,  XIV,  1906,  p.  73. 

6  Macco,  Zeifc.  fur  prakt.  Geol.,  XI,  1903,  p.  29. 

c  Monteiro,  "  Angola  and  the  River  Congo,"  London,  1875,  II,  p.  89. 

<*  Loc.  cit.  inf. 

e  Geog.  Jour.,  XXIV,  1904,  p.  161. 

/Ckoffat,  Revista  de  Sciencias  Naturaes,  1895,  IV,  No.   1. 


424  AFRICA. 

CONGO  FREE  STATE. 

The  gold  occurrences  of  the  southern  portion  of  the  region 
now  the  Congo  Free  State  were  first  described  by  Cameron. a 
They  have  also  been  further  described  by  Cornet, b  but  in  most  detail 
by  Buttgenbach,c  from  whose  account  the  following  is  derived.  The 
very  important  copper  deposits  of  Katanga  ^  contain  also  gold. 
They  lie  in  slates,  sandstones,  and  quartzites.  The  tenor  in  gold  is 
however,  very  low,  the  highest  assay  being  only  about  2  dwts.  per 
ton.  To  the  south  of  Katanga  there  are  numerous  streams  carrying 
gold.  The  richest  placers  are  those  of  Kambove,  which  occur  in 
narrow  gorge-like  streams,  and  also  on  the  plateau  overlying  the 
violet-coloured  slates  through  which  the  streams  run.  Seeing  that 
placers  occur  only  in  those  streams  which  flow  from  the  well- 
known  and  well-defined  copper  belt,  it  is  assumed  that  the  gold 
has  had  a  genesis  in  the  original  copper-pyrites  of  the  ores  that  are 
now  showing  as  copper-carbonates  at  the  surface.  At  Fungurume, 
north-west  of  Kambora,  and  at  Likasi  to  the  south-south-east  there 
are  similar  occurrences  of  alluvial  gold  apparently  associated  with 
the  copper  belt. 

Near  Katanga  also  there  exist  remarkable  auriferous  sedimen- 
tary beds.  At  Ruwe,  10  miles  west  of  Lualaba,  the  country  is  sand- 
stone and  quartzite.  On  its  surface  is  spread  an  ordinary  surface 
debris,  but  cemented  more  or  less  by  limonite,  the  whole  having  a 
yellowish  colour.  This  lateritic  bed  always  contains  gold,  some 
of  which  is  very  coarse,  and  may  weigh  1  to  2  dwts.,  or  may  reach 
even  6  dwts.  in  weight.  The  underlying  beds  are  also  auriferous, 
especially  a  limonitic  conglomerate,  from  which  assays  showing 
tenors  as  high  as  1  •  6  ounces  per  ton  were  obtained.  The  average 
of  24  samples  taken  from  these  beds  gave  :  gold,  7*  8  dwts.  ;  silver, 
5-  2  dwts. ;   and  platinum,  2-  2  dwts.  per  ton. 

The  Kilo  (Ruwe)  goldfields,  about  20  miles  from  the  British 
boundary,  are  reported  to  have  yielded  3,909  ounces  (121-8  kg.) 
during  the  first  five  months  of  1908.  The  produce  of  the  Ruwe 
mines  to  December,  1907,  had  been  16,242  ounces  (499  kg).e 

►•  In  1905,  gold  to  the  amount  of  4,694  ounces  (146  kg.),  valued  at 
£19,130  (478,272  francs)  was  obtained  from  the  Katanga  district; 
in  1906  the  amount  was  nearly  doubled,  8,827  ounces  (275  kg.), 
worth  £34,059,  being  obtained. 

a  "  Across  Africa,"  London,  1877. 

b  Bull.  Soc.   Beige  de  geol.,  XVII,   1903. 

c  lb.,  XVIII,  1904,  p.  173. 

<*Eng.  Min.  Jour.,  April  11,  1908. 

eLMin.   Jour.,   July  4,    1908. 


425 

BRITISH  EAST  AFRICA. 

Gold  is  known  to  exist  in  small  quantities  in  various  parts  of 
this  Protectorate,  but  all  attempts  made  to  find  deposits  of  economic 
value  have  hitherto  resulted  in  failure. 


UGANDA   PROTECTORATE. 

In  September,  1908,  gold  was  reported  to  have  been  found 
in  appreciable  quantity  by  a  geological  survey  party  near  Lake 
Albert  Nyanza,  and  near  the  borders  of  the  Lado  Enclave. 


GERMAN  EAST  AFRICA. 

Many  rivers  between  the  Indian  Ocean  and  Lake  Victoria 
Nyanza  contain  gold.  A  concession  was,  towards  the  end  of  1902, 
granted  over  a  number  of  streams  flowing  into  Lake  Victoria  Nyanza, 
but  was  productive  of  no  definite  result.  In  1899,  in  the  region 
at  the  sources  of  the  Gurumasiva  tributary  of  the  Umbekuru 
(circa  S.  Lat.  10°  15' ;  E.  Long.  38°),  the  alluvial  gold  deposits  of 
New  Klondike  were  discovered.  Two  other  placer  fields  are  known, 
one  near  the  Emin  Pasha  Gulf  on  Lake  Victoria  Nyanza  (Muanza 
district),  and  the  other  about  150  miles  to  the  south-west  on  the 
Iramba  plateau.  Rich  float  gold-quartz  specimens  have  been 
brought  from  the  Useraguru  mountains  and  assayed  from  2  to  6 
ounces  per  ton.  The  auriferous  occurrences  of  the  Iramba  plateau 
have  at  times  aroused  in  the  breasts  of  the  German  colonial 
administrators  hopes  of  a  rich  goldfield  that  are  as  yet  unfulfilled. 

In  the  clay-slates  of  Manani  lower  grade  gold-quartz  veins 
occur,  with  a  tenor  of  only  about  1  dwt.  per  ton.  Lately  gold  has 
been  found  in  the  Mssalala  district  about  50  miles  south  of  Lake 
Victoria  Nyanza. a 

During  1904  prospecting  had  been  carried  on  in  the  Muanza 
(Emin  Pasha  Gulf)  and  Iramba  districts.  In  the  former  district 
gold-quartz  veins  were  discovered.  The  value  of  the  gold  exported 
in  1904  was  £608. 

The  Moama  and  Mara  rivers  here  contain  no  gold,  while  the 
Simiju  does,  but  not  in  payable  quantities.  Near  the  lake  the  rock 
is  granite,  but  further  in  the  interior  schists  with  auriferous  veinlets 
occur.  For  the  greater  part  of  the  year  the  valleys  of  these  streams 
are  waterless. 

On  the  Iramba  plateau,  made  up  partly  of  granite  and 
partly  of  crystalline  schists,  are  numerous  small  and  irregular 
gold-quartz  veinlets,  which  are  poor  in  depth,  but  which  have 
occasionally  shown  secondary  enrichment  near  the  surface.     For 


a  Zeit.  fur  prakt.  Geo!.,  XI,  1903,  p.  194. 


426 


AFRICA. 


example,  assays  from  the  surface  have  yielded  130  ounces  per 
ton,  while  at  30  to  60  feet  deep  the  same  vein  showed  tenors 
of  only  a  few  pennyweights. 

Very  similar  are  the  veins  of  the  Ikoma  goldfield  about  60  miles 
east  of  the  Speke  Gulf  on  Victoria  Nyanza.  At  that  place  five 
parallel  gold-quartz  veins  occur  in  isolated  areas  of  hornblende- 
schist  in  the  prevailing  gneiss.  These  appear  to  be  of  fairly  high 
grade  on  the  surface,  but  are,  like  those  of  Iramba,  very  poor  in 
depth.  Near  Sargidi  village,  three  hours'  journey  north  of  Ikoma, 
occurs  another  vein  of  the  same  type  as  the  foregoing. 

Alluvial  gold  has  been  found  north  of  Nguru  in  a  more  or  less 
brecciated  fragmentary  deposit.  Samples  assayed  as  high  as  1  ounce 
per  ton,  but  the  deposit  nevertheless  appears  to  have  been  of  little 
consequence." 

Gold  to  the  value  of  £1,598  was  exported  from  German  East 
Africa  in  1906. 

NYASS ALAND    PROTECTORATE. 

Gold  occurs  in  the  Shire  Highlands,  but  no  quartz  of  greater 
richness  than  5  dwts.  to  the  ton  has  yet  been  found.  Prospecting 
was  being  carried  on  during  1907. 

MADAGASCAR. 

Gold  was  almost  unknown  in  Madagascar  prior  to  1895,  though 
from  1886  onward  various  mineral  concessions  had  been  granted 
to  English  and  French  capitalists.  These  had  met  with  little  real 
success  despite  the  fact  that  one  of  the  concessionaires  had  in  six 
years  obtained  about  900  kg.,  or  28,935  ounces  gold,  working  with 
natives  and  the  batea.&  After  the  fall  of  Antananarivo  explorers 
spread  on  all  sides,  at  first  meeting  with  little  encouragement. 
Since  then  a  considerable  quantity  of  gold  has  been  obtained,  as  is 
shown  in  the  subjoined  table. 


Year. 

Kg. 

Crude  Ounces. 

1897 

72 

2,315 

1898 

124 

3,986 

1899 

386 

12,410 

1900 

1,114 

35,815 

1901 

1,045 

33,597 

1902 

1,295 

41,634 

1903 

1,910 

61,406 

1904 

2,460 

79,089 

1905 

2,291 

73,655  (£274,998) 

1906 

2,255 

72,498  (£270,613) 

a  Sckmeisser,  Zeit.  fur  prakt.  Geo!..  XIV,  1906,  p.  77. 
fcGascucl,  Ann.  des  Mines,  X.,  Ser.  X,  1906,  p.  85., 


MADAGASCAR.  427 

The  great  rise  in  the  yield  for  1900  and  following  years  was  due 
to  the  discovery  of  the  rich  placers  of  the  Ampasary,  Sakaleona, 
Fanantara,  Mangoro,  Beanandrambo,  and  others  in  the  great  forest 
belt  of  the  eastern  portion  of  the  island. 

In  April,  1905,  a  gold-quartz  vein  was  discovered  at  Ampasimba, 
in  the  eastern  forest  belt,  9|  miles  (15  km.)  from  Beforona,  an  im- 
portant village  on  the  road  from  Tamatave  to  Antananarivo,  and 
close  to  the  road  and  railway.  Other  deposits  were  found  near 
Fianarantsoa,  and  extravagant  hopes  based  on  these  discoveries 
precipitated  a  "boom"  in  which  South  African  capitalists  joined. 
Detailed  examination  proved  the  deposits  to  be  poor,  and  the  "  boom" 
had  collapsed  at  the  end  of  the  year  1905. 

All  the  gold  at  present  produced  from  Madagascar  is  placer 
gold.  The  placers  are  recent,  occupying  either  the  bottoms  of  the 
valleys  or  the  slopes  up  to  a  certain  level.  There  are  three  main 
auriferous  regions  :  — 

(a)  The  eastern  forest  belt  along  the  coast  from  Diego-Suarez  to 
Fort  Dauphin.   Of  this  the  richest  portion  is  from  Fenerive 
in  the  north  to  Manajary  in  the  south.     In  1904  this  region 
furnished  half  the  gold  produced. 
(6)  The  country  in  the  neighbourhood  of  Miandrivago  and  of 
Ankavandra  in  the  west,  with  prolongations  north  and 
south, 
(c)  The  centre  district  along  the  line  from  Antananarivo  to  Fianar- 
antsoa,   producing    in   1904  about  one-sixth  of  the  total 
yield.     The  placers  are,  as  a  rule,  shallow,  but  the  pay- 
streak  may  in  places  be  several  yards  below  the  surface. 
The  pebbles  are  of  quartz,  and  are  rarely  larger  than  the 
fist.     The   gold    occurs    as    scales,    grains,    and   nuggets, 
but  the  latter  are  rare.     The  largest  nugget  yet  found  was 
less  than  16  ounces  in  weight. 
De  Launaya  records  the  occurrence  of  nuggets  in  the  laterite 
of  Madagascar.     They  were  the  largest  that  had  been  obtained 
there,  and  were  doubtless  in  their  original  matrix,  since  they  showed 
no  indication  of  having  been  subjected  to  attrition.     The  black- 
sand  residues  are  remarkable  for  the  abundance  of  black  and  pink 
tourmalines,which  are  probably  to  be  ascribed  to  the  great  develop- 
ment of  pegmatite  in  the  island.     The  placers  are  always  worked 
in  the  native  fashion,  with  native  labour,  the  concessionaire  merely 
buying  the  gold  at  a  fixed  price. 

The  veins  are  either  lenticular  and  lie  in  schistose  rocks 
(quartzite,  mica-,  pyroxene-,  or  amphibolite-schist),  or  are  thin 
auriferous  veinlets  occurring   in  granites  in  the   central  districts. 

a  C.  R.  Acad.  Sci.,  Paris,  1901,  CXXXII,  p.  180. 


AFRICA 


MADAGASCAR.  429 

Numerous  examples  of  both  types  occur,  but  none  are  at  present 
of  economic  importance.  In  1904,  Lacroix  found,  south-east  of 
Ambositra,  grains  of  native  gold  in  situ  in  a  pyroxene-schist. 


PORTUGUESE  EAST  AFRICA. 

The  Portuguese  Manica  goldfields  lie  to  the  north  of  Macequece, 
on  the  Beira-Salisbury  railway.  On  the  west  they  are  bounded  by 
the  Rhodesian  eastern  frontier.  The  mines  are,  therefore,  situated 
in  the  country  at  the  head  of  the  Revue  river  and  its  tributaries. 
The  auriferous  rocks  are  continued  west  into  Rhodesia,  there  forming 
the  Umtali  goldfield.  The  Manica  goldfield  has  an  area  of  about 
180  square  miles.  The  country  of  the  veins  is  Archaean  metamorphic 
schist  derived  apparently  both  from  igneous  and  sedimentary 
members.0  The  members  are  talc-schists,  chlorite-schists,  sericite- 
schists  (derived  from  rhyolites),  amphibolite-schists,  quartz-schists, 
and  mica-schists.  Felsites  and  rhyolites,  often  much  sheared,  are 
interbedded  with  these.  Of  undoubted  sedimentary  origin  are, 
however,  the  clay-slates,  sandstones,  quartzites,  grits,  conglomerates, 
and  limestones.  Traversing  these  and  forming  characteristic 
landmarks  and  features  in  the  landscape  are  laminated  quartzites, 
or,  rather,  quartzose  rocks  banded  with  limonite  (haematite), 
magnetite,  and  white  quartz.  The  lamellae  vary  in  thickness  from 
that  of  a  sheet  of  paper  to  an  inch,  and  are  often  greatly  contorted 
and  crumpled.6  They  may  be  compared  with  similar  rocks  found 
in  the  Archaean  schists  of  India,  Western  Australia,  and  Rhodesia. 
Chlorite-schists  are  found  with  flat  and  rounded  pebbles  forming 
breccias,  boulder  beds,  or  conglomerates.  All  these  rocks  obviously 
belong  to  the  Swaziland  Series. 

The  fundamental  rock  of  the  country  is  here,  as  further  south  in 
the  Transvaal,  a  gneissoid  granite.  Basic  igneous  rocks  (diabase)  are 
very  abundant,  occurring  principally  as  dykes.  Gold  is  found  in 
these  rocks  ;  close  to  the  Rhodesian  frontier  a  diabase  dyke  contains 
secondary  quartz,  with  visible  gold,  pyrite,  and  galena.  Quartz- 
diabase  rock  has  also  been  noted.  The  most  conspicuous  member 
of  the  whole  series  is  the  above-mentioned  banded  haematite- 
quartzite,  the  strike  of  which  is  always  parallel  in  direction  with  the 
planes  of  foliation.  Graphite-schist  occurs  on  Venga  Mount,  north  of 
Macequece,  where  dolomitic  limestone  also  is  found.  Throughout 
the  schists  are  numerous  quartz  veinlets  carrying  from  1  dwt.  5  grains 
to  30  ounces  to  the  ton.  The  average  tenor  of  the  richer  veins  is 
6  to  7  ounces  per  ton.  They  lie  in  the  vicinity  of  the  Revue  and 
Zambusi  rivers.      The  associates   are  the  ordinary  sulphides,  but 

a  Sawyer,  Trans.  Inst.  M.E.,  XIX,  1900,  p.  265;  Id.,  ib.,  XXV,  1903,  p.  627. 
°  Sawyer,  loc.  cit.,  p.  275. 


430  AFRICA. 

from  the  Bragancia  and  Richmond  mines  Couyat a  describes  specimens 
of  quartz  covered  with  mimetite,  vanadinite,  and  wulfenite,  all  due  to 
the  decomposition  of  the  galena  of  the  lodes.  In  1905  2,139  ounces 
gold  valued  at  £7,198,  and  in  1906  2,918  ounces,  worth  £9,622,  were 
obtained  in  Manicaland. 

The  principal  auriferous  region  in  Portuguese  Nyassaland  is  on 
the  Rarico  river,  a  tributary  of  the  Lujende.  In  the  northern  Tete 
district  the  Chifumbase  reef  is  being  worked  on  a  small  scale.  Its 
initial  crushings  have  shown  tenors  of  about  5  dwts.  gold  per  ton. 


RHODESIA. 

North-Eastern  Rhodesia. — The  British  colony  now  known  as 
North-Eastern  Rhodesia,  formed  a  portion  of  the  ancient  kingdom  of 
Monomotapa,  for  the  conquest  of  which,  and  for  the  confiscation  of 
whose  gold  mines,  lying  west  of  Tete,  a  strong  Portuguese  expedition 
set  out  in  1569.  The  expedition  failed  in  its  object,  but  forty  years 
later  the  mines  of  Monomotapa  were  amicably  ceded  to  the  Portuguese. 
The  mines  worked  by  them  in  subsequent  years  were  Pamba  (north 
of  Zumbo  on  the  Zambesi),  Missale  (north  of  Tete  on  the  Portuguese 
frontier),  Mano,  Java  (south  of  Missale),  and  others.  At  Pamba 
the  gold  occurs  in  a  lode  in  talcose  mica-schist.  A  diorite  dyke 
runs  parallel  with  the  lode  for  a  considerable  distance. b  The  great 
mass  of  North-Eastern  Rhodesia  is  granite,  but  it  contains,  as  do  the 
countries  to  the  south,  long,  narrow,  apparently  vertical,  belts  of 
Archaean  schists,  that  lie  generally  between  granite  ranges.  Often, 
as  at  Fort  Jamieson,  they  occur  in  small  and  isolated  patches,  forming 
the  tops  of  the  hills.  The  granite  is  gneissic,  and  appears  to  bear 
much  the  same  relations  to  the  schists  as  have  been  observed  in  the 
gneisses  and  schists  of  Southern  Rhodesia.  At  Sesare  are  vertical 
gneisses  with  quartz-mica-schists  striking  north-north-east.  They 
are  in  places  highly  impregnated  with  copper.  One  of  the  members 
of  the  series  is  a  band  of  coarsely  crystalline  limestone  which  may  be 
traced  for  50  miles.  The  Archaean  schists  at  Sesare  appear  to  have 
been  lying  in  north-east  and  south-west  folds  when  the  granite  was 
forced  into  them.  The  schists  are  the  auriferous  rocks  of  the  country. c 
In  July  and  August  of  1907,  the  Sesare  mine,  milling  with  a  small  10- 
head  battery,  produced  167  and  232  ounces  gold  respectively.  At 
.Missale,  the  tenor  of  the  quartz  is  said  to  be  about  10  dwts.  per  ton. 

Southern  Rhodesia. — The  discovery   in  1866  of   ancient  ruins 
of  Sabaean  architecture  and  of  ancient  gold  mines  at  Zimbabwe,  in 

"  Couyat,  Bull,  de  Museum  d'Histoire  Naturelle,  Paris,  1906,  p.  74. 

b  Lett,  Min.  Jour.,  February  15, 1902,  p.  221  ;   Id.,  ib.,  August  22,  1908,  p.  231. 

c  Wallace,  Gteog.  Jour.,  XXIX,  1907,  p.  389. 


RHODESIA.  431 

the  south-east  portion  of  Southern  Rhodesia,  and  in  other  places 
throughout  the  country  has  given  rise  to  the  hypothesis  that  Rhode- 
sia is  the  Ophir  of  Scripture.  Considerable,  and  at  times  acrimonious 
discussion  has  been  waged  on  the  question,  which  is  fortunately  of 
purely  academic  interest.  According  to  Portuguese  records  gold 
workings  existed  in  Rhodesia  in  the  sixteenth  century,  and  the  gold 
workings  of  the  Manica  fields  were  mentioned  by  da  Silva  in  1788. 
The  natives  (Mashona)  appear  to  have  worked  for  gold,  but  only  in 
the  crudest  of  fashions.  Numerous  old  workings  have  been  described 
by  Messrs.  Hall  and  Neal.a  These  are  especially  numerous  in  the 
vicinity  of  Buluwayo,  where  they  occur  mainly  as  open-cuts,  which 
rarely  reach  below  water-level.  Still,  instances  are  known,  as  at  the 
Globe  and  Phoenix,  where  the  quartz-veins  have  been  followed 
to  depths  of  more  than  200  feet.  The  quartz  was  shattered  by 
"  fire-setting,"  and  was  then  extracted  by  means  of  iron  and  stone 
tools.6 

The  modern  history  of  these  goldfields  dates  from  1865,  when 
ancient  workings  were  recognised  by  Henry  Hartley.  In  the  following 
year  he  discovered  the  Tati  goldfields,  now  within  the  Bechuanaland 
Protectorate.  For  the  next  four  or  five  years  ineffectual  attempts 
were  made  to  open  up  goldfields,  but  no  measure  of  success  was 
attained  until  1891,  when  extensive  prospecting  was  entered  upon. 
Mining  progress  was,  however,  greatly  hindered  during  the  next  de- 
cade by  the  successive  Mashona,  Matabele,  and  Boer  wars.  It  is 
only  during  the  years  of  the  present  century  that,  notwithstanding 
the  great  expenditure  of  capital,  the  true  character  of  Rhodesian 
gold-quartz  veins  has  been  recognised,  with  a  corresponding  increase 
in  output.  The  veins  are  on  the  whole  small,  but  of  fair  grade. 
Large  veins  do  occur,  and  though  low  in  tenor  are  of  increasing  im- 
portance. The  former  type  necessitates  the  employment  of  small 
capitals,  with  correspondingly  low  management  costs. 

The  central  plateau  of  Southern  Rhodesia,  on  an  average  per- 
haps 4,000  feet  above  sea-level,  is  prolonged  both  to  the  south-west 
and  to  the  north-east  along  a  line  connecting  Buluwayo  and  Salis- 
bury. The  rocks  of  the  plateau  are  Archaean  (Buluwayo)  schists 
and  granites,  the  latter  being  considered  by  Mennell  intrusive  into  and 
through  the  former.  The  Buluwayo  schists  are  to  be  regarded  as 
made  up  of  highly  altered  sedimentary  rocks  into  which,  before 
final  metamorphism  took  place,  there  have  been  intruded  great 
masses  of  generally  basic  igneous  rock.  The  oldest  rocks  of  the 
series  appear  to  be  mica  and  talc  schists  and  gneisses.  These  are 
now    closely    associated  with    epidiorites    and    hornblende-    and 

a  "  Ancient  Ruins  of  Rhodesia,"  London,  1902,  p.  73. 

6  Mennell,  "  The  Rhodesian  Miner's  Handbook,"  Buluwayo,  1908,  p.  51. 


432  AFRICA. 

chlorite-schists,  obviously  basic  intrusions.  The  younger  rocks  of  the 
complex  (Banded  Ironstone  Series  of  Mennell)  are  sheared  conglo- 
meratic and  arenaceous  beds,  phyllites,  and  gneissic  bands,  the  last 
of  which  may  have  resulted  from  the  crushing  of  acid  intrusions  or 
tuffs.  The  most  characteristic  bed  of  the  series  is,  however,  the 
"  banded  ironstone,"  which  is  obviously  a  similar  rock  to  that 
known  as  "calico-rock"  in  the  Transvaal,  and  as  banded hsematite- 
magnetite-quartzites  in  Southern  India,  and  as  laminated  quartzites 
in  Western  Australia.  Faulting  and  crush-phenomena  are  frequent 
throughout  the  Buluwayo  schists,  and  apparently  determine  the 
occurrence  of  the  quartz-reefs  and  auriferous  impregnations  from 
which  the  gold  of  Rhodesia  is  obtained.  Occasionally  the  rocks 
themselves  may  be  impregnated  with  gold,  as  in  the  hornblendic 
gneiss  ("  diorite  ")  of  the  Lomagunda  district,  and  in  the  similar 
rock  of  the  Kimberley  mine  in  the  Mazoe  district.  In  Matabeleland, 
near  Buluwayo,  the  banded  ironstones  are  auriferous.  Basic  rocks 
are  largely  intrusive  into  the  Buluwayo  schists,  and  are  mainly 
dolerite  and  diabase. a 

All  the  leading  Rhodesian  gold  mines  are,  therefore,  within  the 
schistose  areas,  but  are  nevertheless  generally  close  to  the  granite. 
Both  auriferous  quartz-veins  and  auriferous  impregnations  of  rock 
occur,  and  in  fairly  equal  numbers.  Of  the  former,  the  Surprise, 
Globe  and  Phoenix,  Tebekwe,  Penhalonga,  Antenior,  Morven, 
Killarney,  and  East  Gwanda  mines  are  examples  ;  of  the  latter, 
the  Wanderer,  Ayrshire,  Eldorado,  Jumbo,  Grant,  Riverslea, 
Gaika,  and  Sabiwa  are  typical.  The  following  grouping  is  adopted 
by  Mennell  :  — h 

I.  Reefs. — (a)  In    the   basement   rocks  :      Globe    and   Phoenix,   Surprise, 
Tebekwe,  Bonsor. 
(&)  In  banded  ironstone  :    Camperdown   (upper  reef),  Bristol, 
Veracity. 

(c)  In  conglomerate  :  Bell,  Abercorn. 

(d)  In  epidiorite,   &c.  :  Antenior,  Beatrice,    Killarney,    Sheba, 

Jessie,  Joker. 

(e)  In  granulite  :   Valley. 

(/)  At  granite  contacts :  Geelong,  Colleen   Bawn,  Battlefields, 
Washington. 

II.  Impregnations. — (a)  In  basement  schists  :  Gaika. 

(6)  In    banded    ironstone :     Wanderer,     Sabiwa,    Camperdown 
(lower  reef),  Concession  Hill,  Giant  (partly). 

a  Gregory,  Trans.  Inst.  M.E.,  XXXI,  1906,  p.  47;  Id.,  Trans.  Inst.  Min.  Met., 
XV,*  1906,  p.  563  ;  Mennell,  "  Geology  of  Southern  Rhodesia,"  Rep.  No.  2,  Buluwayo 
Museum,  1904,  p.  42  ;  Id.,  Fifth  Ann.  Rep.  Buluwayo  Museum,  1907  ;  Id.,  Trans.  Geol. 
Soc.  S.A.,  VIII,  1906,  p.  82  ;   Chalmers  and  Hatch,  Geol.  Mag.,  1897,  pp.  193-203. 

b  "  Mineral  Wealth  of  Rhodesia,"  Buluwayo,  1907,  p.  26. 


RHODESIA.  433 

(c)  In  conglomerate  :   Eldorado,  &c.,  Riverslea. 

(d)  In  granulite  :  Ayrshire,  Bushtick. 

(e)  In  chlorite-  and  talc-schist  :  Giant  (chiefly). 
(/)    In  granite  :  Commonwealth. 

The  impregnations  are  an  interesting  class  of  deposit. 
At  the  Wanderer  mine,  which  treats  a  larger  quantity  of  ore  than 
any  other  mine  in  Rhodesia,  and  at  the  lowest  working  cost  (6s.  9d. 
per  ton),  the  ore-body  is  a  much-crushed  zone  of  banded  ironstone, 
situated  at  a  contact  with  the  Conglomerate  Series.  The  workable 
width  of  the  zone  reaches  in  places  60  feet,  with  a  tenor  of  3  to  4 
dwts.  per  ton.  The  Conglomerate  Series  is  being  actively  prospected, 
especially  in  the  Lomagundi  and  Sebakwe  districts. 

The  matrix  of  the  Ayrshire  lode  has  been  the  subject  of  con- 
siderable speculation. a     It  is  an  impregnated  band  of  hornblende- 
biotite-granulite  or  gneiss  situated  about  50  to  200  feet  distant  from 
the  granite.     According  to  Mennell  it  is  doubtless  a  mixed  rock, 
resulting  from  injection  of  granitic  material  into  the  schists  and  from 
contact-metamorphism  by  intrusive  granitic  material.     As  described 
by  Spurr,  the  rock  is  composed  principally  of  felspar  (oligoclase- 
albite)  and  a  pale  green  hornblende.     Quartz  is  also  abundant,  and 
there  is  some  biotite.     Magnetite  and  epidote  are  always  present. 
The  free  gold  grains  are  almost  entirely  confined  to  a  band  of  horn- 
blende,  containing   much    magnetite,    that    is     situated    between 
two    bands    composed     chiefly    of     quartz    and    felspar     grains. 
It     is     evident     that     the     hornblende,     magnetite,      and    gold 
are   of    contemporaneous    deposition.       As    a    rule,    the    gold    is 
set  with    a    long    axis    of    the   grain  parallel  with  the    cleavage, 
but    not    necessarily    along    a    cleavage     plane.      The    rock  is    a 
hornblende-biotite-gneiss    derived  from    the    metamorphism  of    a 
pre-existing,  probably  basic,  igneous  rock,  in  which  the  gold   had 
previously  been  deposited.     The  country  in  which  the  hornblende- 
gneisses  occur  is  hornblende-schist.     The  Ayrshire  mine  working 
on  this  ore  treats  8,000  tons  of  6  dwt.  ore  monthly.     The  Common- 
wealth mine  is  an  example  of  auriferous  impregnation  of  a  normal 
granite.     The  granite  carries  pyrite.     The  rocks  of  the  Globe  and 
Phoenix,  Sebakwe  district,  are  described  by  Gregory  as  mica-diorite- 
schists.     The  gold  is  generally  free,  and  is  associated  with  pyrite 
and  jamesonite.     The  Gaika,  somewhat  to  the  south  of  the  Globe 
and    Phoenix,  is  in  the    same    rock,   which    is    here    altered   even 
further  to  talc-dolomite-schists,  containing  also  epidote,  sphene,  and 
calcite. 

The   Rhodesian   auriferous  conglomerates  are    richest  at  the 
Eldorado  and  Rowdy  Boys  mines,  Lomagundi,  near  the  Hunyani 

«Berrington,  Eng.  Min.  Jour.,  July  11,  1903;  Spurr,  lb.,  Oct.  3,  1903. 
Dl 


434 


AFRICA. 


river.  They  are  probably  sedimentary  conglomerates  ;  they  have 
been  traced  for  a  distance  of  2|  miles,  and  in  places  have  a  tenor  of  an 
ounce  gold  per  ton.  Other  sedimentary  conglomerates  occur  in  the 
Sebakwe  and  the  Selukwe  districts,  but  these  have  not  so  far  proved 
notably  auriferous.  There  are  also  in  Southern  Rhodesia  pseudo- 
conglomerates,  which  are  in  reality  crush-conglomerates.  These 
occur  at  the  Tebekwe  mine,  Selukwe,  and  at  the  Wanderer  mine. 

The  Penhalonga  mine,  which  promises  to  be  the  principal  pro- 
ducer in  Southern  Rhodesia,  lies  10^  miles  north  of  Umtali  on  the 
eastern  border  of  Rhodesia.  Its  ore-body  varies  in  width  from 
25  to  50  feet,  of  which  some  8  to  20  feet  may  be  economically  worked. 
It  is  made  up  of  a  series  of  quartz  lenticles  occupying  a  zone  of  crush- 
ing in  soft  chloritic  schists  of  the  Swaziland  Series.  In  the  oxidised 
portion  of  the  lode  crocoisite  (chromate  of  lead)  was  abundant. 
In  depth  this  mineral  gave  place  to  galena,  with  which  blende, 
pyrite  and  chalcopyrite  are  associated." 

Mennell  records  the  existence  of  tellurium  in  arsenopyrite  from 
the  Lomagundi  mine  as  denoted  by  analysis,  but  the  telluride  minerals 
do  not  appear  to  have  been  isolated. & 

The  placer  deposits  of  Southern  Rhodesia  are  not  extensive,  nor 
are  they,  so  far  as  is  known,  of  high  grade,  especially  in  the  high 
veldt.  The  valuable  accessible  alluvial  deposits  have  probably 
been  long  ago  worked  out  by  the  ancients. 

The  following  is  the  total  gold  yield  of  Southern  Rhodesia  to  the 
end  of  1907  :  — 


To  1898  inclusive 
1899 
1900 
1901  " 
1902 
1903 
1904 
1905 
1906 
1907 


Crude  ounces. 

24,555 -65 

65,303-65 

91,940-40 

172,061-43 

194,169-31 

231,872-26 

267,737-37 

409,836-44 

553,985-58 

612,052-38 

2,623,514-47 


This  amount  of  gold  has  a  probable  value  of  some  £9,330,000. 
The  average  yield  of  the  quartz  crushed  during  1905  and  1906  was 
28-  95s.  per  ton. 


a  Townsend,  Min.  Jour.,  April  4,  1908. 

h  Mennell,  Proc.  Rhod.  Scientific  Assn.,  Ill,   1902,  p.  21. 


I 


RHODESIA. 


435 


The  subjoined  table  shows  the  relative  importance  of  the  princi- 
pal gold  mines  of  Rhodesia  as  estimated  from  their  yield  for  the 
month  of  September,  1907  a  :  — 

OUTPUT  OF  RHODESIAN  MINES  IN  SEPTEMBER,  1907. 


Tons  milled. 

Value. 

Matabeleland. 

Gwanda 

8,203 

£12,032 

Globe  and  Phoenix 

6,000 

12,618 

Selukwe 

6,410 

8,002 

Surprise 

2,926 

4,214 

Nelly 

1,700 

4,819 

Wanderer 

16,368 

7,777 

Mashonaland. 

Battlefields 

1,535 

5,410 

Giant 

4,322 

9,375 

Beatrice 

1,525 

2,550 

Ayrshire 

8,000 

10,170 

Eldorado 

2,584 

5,652 

Jumbo 

1,752 

7,275 

Penhalonga 

7,900 

6,780 

Rezende 

3,700 

5,257 

BECHUANALAND  PROTECTORATE. 

The  only  fields  of  any  importance  within  this  protectorate  are 
those  of  the  Tati  district.  They  were  discovered  by  Henry  Hartley 
and  Carl  Mauch  in  1866  and  were  worked  by  the  London  and  Lim- 
popo Company  from  1869  to  1872.  During  that  time  they  yielded 
only  some  2,000  ounces.  They  have  recently  been  worked  by  English 
capital,  but  with  no  great  measure  of  success.  Their  veins  lie  in 
country  similar  to  that  of  Southern  Rhodesia. 


TRANSVAAL. 


Witwatersrand.—  One  of  the  most  remarkable  of  modern 
goldfields,  both  from  an  economic  and  from  a  scientific  point  of 
view,  lies  within  the  Transvaal  Colony.  The  richness,  actual  and 
potential,  of  the  Witwatersrand  goldfield  has,  during  the  last  decade, 
at  times  directly,  more  often  indirectly,  swayed  the  course  of  high 
politics  in  Europe.  The  connected  chain  of  mines  that  lies  partly 
west  and  partly  east  of  Johannesburg,  produces  one-third  of  the 
world's    annual    supply    of    gold,    and    considerably    more    than 


a  Wilkinson,  W.  F.,  Eng.  Min.  Jour.,  Jan.  4,  1908. 


430  AFRICA. 

the  whole  output  of  the  next  gold-producing  country — the 
United  States,  with  its  numerous  rich  fields,  vein  and  placer. 
The  mines  are  spread  along  a  belt  for  some  62  miles,  from 
Randfontein  on  the  west  to  Holfontein  on  the  east.  Of  this 
distance  a  length  of  some  12J  miles  near  Johannesburg  yields  76 
per  cent,  of  the  gold  won.  The  conglomerate  beds  have,  however, 
been  proved  by  outcrops  and  by  borings  for  164  miles  ;  their 
continuity  is  concealed  for  123  miles,  and  is  interrupted  by  faults 
and  dykes  for  31  miles,  making  a  total  of  308  miles  of  actual  and  of 
probable  extension.  The  district  derives  its  name  from  a  ridge 
(the  Witwatersrand)  that  rises  a  few  hundred  feet  above  the  general 
level  (5,500  feet)  of  the  plateau  or  High  Veldt,  and  forms,  indeed,  the 
main  divide  between  streams  flowing  to  the  India  and  to  the  Atlantic 
Oceans.  The  range  or  rather  ridge,  in  conformity  with  the  strike 
of  the  underlying  strata,  has  a  general  east  and  west  trend.  It,  as 
well  as  the  High  Veldt  in  the  neighbourhood,  carried  a  very 
scanty  arboreal  vegetation  that  speedily  disappeared  on  the  advent 
of  the  miner. 

The  presence  of  gold  in  the  Witwatersrand  appears  to 
have  been  discovered  on  the  farm  Langlaagte  by  one 
Arnold  in  1885,  and  a  small  five-stamp  battery  was  shortly 
afterwards  erected  on  the  spot.  It  was  soon  found  that 
the  gold  was  confined  to  the  conglomerate  outcrop  which 
was  even  then  traced  for  many  miles.  To  it  was  given  the  term 
'  banket,"  of  Boer  origin,  and  signifying  almond-rock,  owing 
to  the  fancied  resemblance  of  the  white  quartz  pebbles  within  the 
brown  oxidised  matrix  to  the  almonds  in  that  confection.  In  1886 
several  farms  were  proclaimed  open  to  mining,  and  in  the  same  year  a 
great  "  rush  "  set  in  towards  the  Witwatersrand.  Johannesburg 
was  marked  off.  It  owed  its  name  to  the  circumstance  that  each  of 
the  four  Boer  dignitaries  who  selected  the  town-site  owned  the 
prenomen  of  Johannes.  A  boom,  speedily  followed  by  the  inevitable 
panic,  took  place  early  in  1899,  and  for  four  years  the  Rand,  as  it  is 
familiarly  known,  was  looked  on  with  some  disfavour.  The  steady 
development  of  the  reefs  during  the  period  of  depression  and  more 
especially  the  steadily  increasing  gold-yield  brought  about  a  complete 
restoration  of  confidence.  In  1895-6  a  considerable  amount  of  British 
and  foreign  capital  was  invested.  The  mine  returns  and  share 
values  alike  increased  until  the  declaration  of  war  towards  the  end 
of  1899.  More  or  less  steady  work  was  resumed  in  1902,  the  richer 
patches  and  mines  having  been  during  the  war  spasmodically  worked 
by  the  Boer  Government.  In  1904  the  annual  yield  exceeded 
by  44,000  ounces  the  highest  previous  return,  and  each  succeeding 
year  has  since  shown  a  material  increase. 


TRANSVAAL. 


437 


The  following  table  indicates  the  gold  production,  since  1884, 
both  of  the  Witwatersrand  district  and  of  the  Transvaal  generally : — 

TRANSVAAL   GOLD   PRODUCTION." 


Witwatersrand  District. 

Outside  Mines. 
Value. 

Transvaal 

\  ear. 

Tons  Milled. 

Value. 

Value  per 
Ton  Milled. 

Total. 

1884-9 

1.000.000 

£2,440,000 

Shillings. 
48-83 

£238,231 

£2,678,231 

1890 

702,838 

1,735,491 

47-4 

134,154 

1,869,645 

1891 

1,175,465 

2,556,328 

44-2 

367,977 

2,924,305 

1892 

1,921,260 

4,297,610 

43-4 

243,461 

4,541,071 

1893 

2.215,413 

5,187,206 

47-0 

293,292 

5,480,498 

1894 

2,027,365 

6,963,100 

49-2 

704,052 

7,667,152 

1895 

3,456,575 

7,840,779 

45-2 

728,776 

8,569,555 

1896 

4,011,697 

7,864.341 

39-2 

739,480 

8,603,821 

1897 

5,325,355 

10,583,616 

39-74 

1,070,109 

11,653,725 

1898 

7.331,446 

15,141,376 

41-3 

1,099,254 

16,240,630 

1899 

6,763,533 

15,089,561 

43-84 

661,220 

15,750,781 

1900 

552.929 

1,464,634 

65-82 

.... 

1,464,634 

1901 

412,006 

1,014,687 

49-25 

81,364 

1,096,051 

1902 

3,416,813 

7,179,074 

42-00 

74,591 

7,253,665 

1903 

6,105,016 

12,146.307 

39-79 

442,941 

12,589,248 

1904 

8,058,295 

15,539,219 

38-46 

515,590 

16.054,809 

1905 

11,160,422 

19.991,658 

35-82 

810,416 

20,802,074 

1906 

13,571,554 

23,615,400 

34-8 

964,587 

24,579,987 

1907 

15,383,000 

26,421,837 

34-2 

982,081 

27,403,918 

Total 

£187,072,224 



£10,151,576 

£197,223,800 

The  dividends  paid  since  1887  are  shown  in  the  subjoined  table 
DIVIDEND  LIST  OF  TRANSVAAL  GOLD-MINING  COMPANIES* 


Year. 

Dividends. 

Year. 

Dividends. 

Year. 

Dividends. 

1887 

£12,976 

1894 

£1,527,284 

1901| 

£415.813 

1888 

112,802 

1895 

2,046,852      . 

1902| 

2,121,126 

1889 

432,541 

1896 

1,513.682 

1903 

3,345,502 

1890 

254,551 

1897 

2,707,181 

1904 

3,877,624 

1891 

334,698 

1898 

4,848,238 

1905 

4,832,436 

1892 

879,320 

1899f 

2,946,358 

1906 

5,735,161 

1893 

955,358 

1900t 

1907 

6,937,187 

f  War 

period,  Oct.  ] 

1,  1899.  to 

May  31,  1902. 

Total... 

£45,836,690 

*  Chamber  of  Mines  Reports,  Johannesburg. 

The  "  outside  mines  "  of  the  first  table  includes  all  those  not 
on  the  northern  limb  of  the  Witwatersrand  sync  line,  and  not  in  the 
immediate  neighbourhood  of  Johannesburg.     They  are  distributed 


438  AFRICA. 

over  the  goldfields  of  Heidelberg,  Klerksdorp,  Barberton,  Lydenburg, 
and  Pietersburg,  with  a  few  minor  fields.  Their  comparative 
importance  is  best  shown  by  the  following  table  :  — 

GOLD  YIELD  OF   "OUTSIDE  FIELDS"  FOR  YEAR  ENDING 

30th  JUNE,  1906.a 


District. 

Ounces. 

Value. 

Pretoria  : — Barberton,  Lydenburg  and  Pietersburg     . . 

Heidelberg 

Klerksdorp 

126,899 
33,933 
18,366 

£539,030 

144,139 

78,021 

The  largest  individual  "  outside  mines  "  are  the  Nigel  in  the 
Heidelberg  district,  and  the  Glynn's  Lydenburg  and  Transvaal 
G.M.  Estates,  both  in  the  Lydenburg  district. 

In  1907  there  were,  on  the  Rand  line,  67  producing  mines,  crush- 
ing their  ore  through  8,255  stamps.  During  the  financial  year  ending 
June  30th,  1907,  they  produced  gold  to  the  value  of  £26,640,490, 
the  distribution  of  which  was  apportioned  as  follows  :  — 


Working  costs 

. .     £17,000,000 

63-8  per  cent 

Dividends 

6,750,000 

25-3 

Reserve  fund 

2,209,490 

8-6 

Profit  tax 

600,000 

2-3         „ 

£26,640,490  100-0 

The  geology  of  the  southern  and  south-western  areas  of  the 
Transvaal  is,  in  its  general  features,  now  fairly  well  known.  The 
oldest  rock  in  the  neighbourhood  of  the  Witwatersrand  is  the  granite 
that  lies  to  the  north.  It  is  regarded  by  Jorissen,^  and  also  by 
Hatch  and  Corstorphine,c  as  intrusive  into  the  Swaziland  (Archaean) 
schists,  so  extensively  developed  to  the  west,  north,  and 
east  of  the  Transvaal.  Overlying  the  granite,  and  after  a  great 
separating  unconformity,  are  the  beds  of  the  Witwatersrand  System, 
consisting  of  a  series  of  slates,  quartzites,  and  conglomerates, 
subdivided  into  an  upper  and  a  lower  division.  These  lie  to  the 
south  of  the  granitic  area,  and  are,  from  the  present  point  of  view,  the 
most  important  in  the  Transvaal.  They  are  bent  into  a  syncline, 
some  30  miles  in  breadth  and  more  than  100  miles  in  length.  Suc- 
ceeding the  Witwatersrand  System,  are  great  flows  of  amygdaloidal 
diabase  lavas.  These  in  their  turn  are  overlain  by  the  conglomerates, 
quartzites,   dolomites,   and  shales  of  the  Potchefstroom    System, 

a  Ann.  Rep.  Govt.  Mines  Dept.,  Transvaal,  1906,  Table  XI. 

6  Trans.  Geol.  Soc.  S.A.,  VII,  1905,  p.  30. 

c "  Geology    of   South    Africa,"   London,    1905,    from    whence    most    of    the 
succeeding  geological  details  are  derived. 


TRANSVAAL. 


439 


subdivided  into  the  Black  Reef,  Dolomite,  and  Pretoria  Series. 
The  beds  of  the  Potchefstroom  System,  together  with  minor  deposits 
of  Dwyka  and  Ecca  beds  of  much  later  age,  fill  the  Witwatersrand 
syncline  between  its  northern  and  southern  limbs.  The  general 
relation  of  the  older  beds  is  shown  in  the  following  table  :— a 


Age. 

System. 

Series. 

Devonian 

Waterberg 

Waterberg. 

Potchefstroom 

Pretoria. 
Dolomite. 
Black  Reef. 

Ventersdorp 

Klipriversberg  Amygdaloid, 
Boulder  Beds,  and  Volcanic 
Breccias. 

Cambrian  or 

Pre-Cambrian 

Witwatersrand 

Upper 
Division 

Lower 
Division 

Elsburg. 
Kimberley. 
Bird. 

Main  Reef. 
Doornfontein 

Slates  to 
Orange  Grove 
.      Quartzite. 

Archaean 

Swaziland. 
Intrusive  Granite. 

The  basal  member  of  the  lower  division  of  the  Witwatersrand 
System  is  the  Orange  Grove  Quartzite,  which  outcrops  as  an  escarp- 
ment 300  feet  in  height  overlooking  the  granite  to  the  north.  There 
is,  of  course,  a  great  unconformity  in  time  between  the  igneous  and 
the  sedimentary  rock,  and  a  still  greater  where  the  basal  member 
of  the  Witwatersrand  System  rests  directly  on  the  Swaziland 
schists.  Overlying  the  Orange  Grove  Quartzite  comes  the 
highly  ferruginous  (with  magnetite)  Water  Tower  Slate,  succeeded 
in  its  turn  by  the  Ripple-marked  Quartzite  and  by  the  Red  Slates  — 
soft  red  ferruginous  beds.  Next  in  order  of  upward  succession  is  a 
peculiar  felspathic  quartzite  bed,  probably  an  original  arkose. 
The  rusty  weathering  of  the  felspar  has  suggested  the  term 
Speckled  Bed.  Above  the  Speckled  Bed  lie  the  Hospital  Hill 
Slates  containing,  near  their  base,  characteristically  contorted  and 
striped  bands  of  red  jasperoid  quartz,  white  quartz  and  specular 
iron  and  magnetite,  resembling  often  the  "  calico-rock  "  (banded 


a  Based  on  Hatch  and  Corstorpliine,  loc.  cit.,  p.  114. 


440 


AFRICA. 


hsematite-magnetite-quartzite)  of  the  Swaziland  schists,  with  which 
they  have  often  been  confounded,  and  recalling  strongly  the  features 
of  the  Bijawar  rocks  of  northern  India.  South  of  the  slates  are 
the  Hospital  Hill  Quartzites,  followed  by  the  readily-weathered 
slates  of  the  Doornfontein  Beds  and  the  Red  Bar,  completing 
the  sequence  of  the  Lower  Division  on  the  northern  limb  of  the 
syncline.  In  a  section  across  the  Central  Rand  the  width  of 
the  outcrop  of  the  division  is  some  2\  miles.  With  a  southerly 
dip  of  45°  to  85°,  the  individual  thickness  of  the  beds  is  estimated  as 
follows  :•- 


Feet 

Red  Bar 

. . 

450 

Doornfontein  Beds  (Slates 

and  Quartzites)    . . 

5,500 

Hospital  Hill  Quartzite  . . 

. . 

1,400 

Hospital  Hill  Slate 

. . 

620 

Speckled  Bed 

.  . 

20 

Red  Slate 

.  . 

1,800 

Ripple-marked  Quartzite 

. . 

60 

Water  Tower  Slate 

. . 

1,400 

Orange  Grove  Quartzite.. 

1,400 

12,650 

Both  to  the  east  and  to  the  west  of  the  above  section,  the  thick- 
nesses of  the  several  beds  vary  considerably,  and  other  beds,  having 
no  representatives  in  the  foregoing  section,  may  in  other  sections 
be  intercalated. 

While  the  Lower  Division  consists  mainly  of  slates,  with  few 
coarser  beds,  the  Upper  Division,  considered  broadly,  is  made  up  of 
alternating  conglomerates,  grits,  and  quartzites,  the  conglomerate 
members  carrying  the  auriferous  content  for  which  the  beds  are 
famous.  The  Main  Reef  Series  (conglomerate),  economically  by 
far  the  most  important  member  of  the  whole  group,  lies  at  the 
bottom  of  the  division.  The  chief  conglomerate  bands  of  the  Upper 
Division  occur  on  five  horizons  well  separated  by  finer  quartzites 
and  grits,  and  are  in  descending  order  :  — 

Elsburg  Series. 
Kimberley  Series. 
Bird  Reef  Series. 
Livingstone  Reef  Series. 
Main  Reef  Series. 

The  Main  Reef  Series  has  naturally  been  followed  with  great 
care,  and  has  been  traced  over  a  length  of  46  miles.  Its  thickness 
varies  considerably,  but  may  be  said  to  range  above  and  below  120 
feet.  Its  pebbles  are  mainly  of  white  or  smoky  quartz  embedded 
in  a  quartzitic  matrix.     When  considered  broadly,  the  beds,  both  of 


A   GEOLOGICAL    MAP 

THE  SOUTHERN   TRANSVAAL 


5 


—    scale  q 

5 10 


r  / 


<     X 


BY 


FREDERICK  H.  HATCH.  Ph.  D..F.G.S., Assoc. M.lnst.C.ET 
formerly  of  the  Geological  Survey  of  England  &  Wales. 


REFERENCE 


KAROO  SYSTEM     Transvaal  Coal  Measures  {sandstones  grits  shales  fireclay  $  coal  seamsj. BBB53 

' Maqaliesberq  &  Gatsrand  Series^'i^tzites  flagstones  fsAafeswa*  inta:bcdoTedf-%Z^A 

3  ^  sheets  of  basic  igneous  rock )  


CAPE 
SYSTEM 


Dolomite  &  Chert  Series  (ntagjiesian  if  siliceous  limestones  cherts  ^cherCbreccia).. 

Black  Reef  Formation  (quartzitc  %  conglomerate] ,   — . 

Banket  Formation  or  Witwatersrand  Beds  (guartxittsQ conglomerates; 

Hospital  Hill  Series  louartzites  4- ferruginous  shales) 


— — : t— i 


ARCH /E AN  SYSTEM  Igneous  complex  of  Granitic  racks V<^<?A 

Volcanic  rocks,  chiefly  rhyolites  and  and t sit et    W/Z/ZA 

Basic  igneous  rocks  of  various  ages,  basalt,  diabase,  melaphyre,  etc 11111111111 


Outcrop  of  auriferous  conglomerate  (Banket)  beds:  viz,  B?ad 

Sena. 


Faults 


■Randfontein^0' 
reef.Elsburg Series. Kimbcrliy         i  J       ^T^SS^ -^*        -ih'''4 

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MILES 


TRANSVAAL. 


441 


conglomerate  and  of  intervening  quartzite,  assume  a  somewhat 
lenticular  character,  as  might  indeed  be  expected  from  a  considera- 
tion of  their  origin,  which  is  generally  believed  to  be  littoral. 

In  a  typical  section  across  the  Central  Rand,  the  Main  Reef 
Series  consists  of  three  workable  beds  of  conglomerate  named,  in 
ascending  order,  the  Main  Reef,  the  Main  Reef  Leader,  and  the 
South  Reef.  Other,  but  non-payable,  conglomerate  bands  are  found 
in  some  mines  within  the  Main  Reef  series,  viz.,  the  North  Reef, 
some  30  feet  below  the  Main  Reef  ;  the  Middle  Reef,  between  the 
Main  Reef  Leader  and  the  South  Reef  ;  and  the  South  Reef  Leader, 
about  2  feet  below  the  footwall  of  the  South  Reef. 

The  Livingstone,  Bird  Reef,  and  Kimberley  Series  of  similar 
conglomerates  are  of  no  present  economic  value.  The  Elsburg 
Series,  consisting  of  the  usual  alternations  of  conglomerate  and 
quartzite,  succeeds  the  thick  quartzites  lying  above  the  Kimberley 
Series.  Whether  they  do  so  conformably  is,  however,  a  moot  point. 
The  balance  of  evidence  appears  to  be  in  favour  of  an  unconformity. 
The  Elsburg  Series  contains  gold,  but  not  in  sufficient  quantities  to 
warrant  mining  operations  on  it.  The  following  typical  sections" 
indicate  the  general  relations  of  conglomerates  and  quartzites  :  — 


I. — Section  through  the  Aurora  Mine. 

Elsburg  Series  (including  intervening  quartzites) 

Quartzites,  with  intervening  conglomerates 

Slates  and  Quartzites 

Bird  Reef  Series 

Quartzites 

Main  Reef  Series 


Feet, 

3,000 
4,440 
1,450 

100 
1,700 

160 

10.850 


II. — Section  through  Simmer  and  Jack  Mine  and  the  Rand 
Victoria  Borehole. 


Quartzites  above  Elsburg  Series 

Elsburg  Series 

Quartzites 

Kimberley  Series  (including  quartzite)    .  . 

Slates  

Quartzite  (in  part  dyke) 
Bird  Reef  Series  (including  quartzite)    .  . 
Quartzite   to   footwall   of   Main   Reef   Series   (including 
Livingstone  Reef  Series) 


Feet. 
1.400 

2,800 

1,800 

1,800 

500 

800 

300 

1.700 
11.100 


Above  the  Elsburg  Series,  but  separated  from  it  by  a  great  un- 
conformity, lie  the  acid  and  basic  lavas,  tuffs,  breccias,  and  con- 
glomerates of  the  Ventersdorp  System.     The  predominant  basic 


"  Hatch  and  Corstorpiiine,  loc.  cit.,  pp.  123,  124. 


442 


AFRICA. 


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TRANSVAAL.  443 

lavas  are  amygdaloidal  and  porphyritic  diabases  (Klipriversberg 
amygdaloid).  These  are  probably  a  later  manifestation  of  the  same 
volcanic  energy  that,  during  the  deposition  of  the  conglomerates 
and  quartzites  of  the  Witwatersrand  System,  laid  down  contem- 
poraneously with  them  (as  is  perhaps  proved  by  the  presence  of 
amygdaloids)  extensive  flows  of  diabase.  These  are  especially  well 
developed  in  the  Eastern  Rand,  where  one  flow,  lying  over  the  Bird 
Reef  Series,  reaches  a  thickness  of  150  feet.  Basic  dykes,  intrusive 
through  the  Witwatersrand  Beds,  are  numerous.  They  include 
norites  and  diorites.a  The  normal  type  is,  however,  an  uralitised 
diabase. 

Above  the  rocks  of  the  Ventersdorp  System  there  occur,  within 
the  area  shown  on  the  accompanying  map,  the  Black  Reef, 
Dolomite,  and  Pretoria  Series  of  the  Potchefstroom  System.  Of 
these  the  Black  Reef  Series  is  auriferous,  but  has  been  little  worked 
except  at  Klerksdorp. 

As  may  be  seen  from  an  inspection  of  the  map,  the  Witwaters- 
rand Beds  are  irregularly  exposed  over  an  area  180  miles  long  from 
east  to  west,  and  100  miles  broad  from  north  to  south.  The  Johan- 
nesburg mines  are  situated  towards  the  north-eastern  corner  of  this 
area,  where  the  older  beds  have  been  exposed  along  a  north-east  to 
south-west  anticlinal  axis  by  the  denudation  of  the  Dolomite  and 
Black  Reef  Series.  Passing  south-west  from  Krugersdorp  along  the 
strike  of  the  beds,  the  endlong  pitch  of  the  anticlinal  axis  is  found  to 
carry  the  older  beds  beneath  the  Black  Reef  and  Dolomite  Series 
to  reappear  again  some  16  miles  east  of  Ventersdorp,  as  a  wrapping 
round  an  Archaean  granitic  mass  in  the  High  Veldt.  Here  the 
sedimentary  beds  dip  away  from  the  granite,  certainly  on  the  north 
and  east,  and  possibly  also  on  the  south-west.  The  south-eastern 
limb  of  this  anticline,  or,  as  it  may  more  conveniently  and  simply 
be  termed,  the  north-western  limb  of  the  main  syncline,  extends  from 
Klerksdorp  in  the  south-west  to  Boksburg  in  the  north-east.  The 
south-eastern  synclinal  limb  is  not  so  well  defined  as  the  preceding, 
but  is  nevertheless  strongly  exposed  in  the  Heidelberg  and  Venter- 
skroon  districts,  disappearing  beneath  younger  beds  along  the  Vaal 
River  in  the  neighbourhood  of  Vereeniging. 

The  auriferous  conglomerates  of  the  Nigel  Series  in  the  Heidel- 
berg district  have  been  definitely  identified  with  the  Van  Ryn 
Reef  Series — the  eastern  continuation  of  the  Main  Reef  Series  beyond 
the  Boksburg  break.  The  most  easterly  exposure  of  the  Witwaters- 
rand beds  is  near  Springs,  but  they  have  been  proved  by  boreholes 
to  continue    a   little    farther  east   beneath   the    overlying   strata, 

a  Henderson,  "  Petrograpkical  and  Geological  Investigations  of  Certain  Transvaal 
Norites,  Gabbros,  Pyroxenites,  and  other  South  African  Rocks,"  London,  1898. 


TRANSVAAL. 


445 


cutting  out  against  a  hidden  granite  ridge.  They  are  here  very 
flat,  and  are  apparently  disposed  to  form  an  eastern  side  to  the 
basin. a 

The  dip  of  the  Main  Reef  Series  varies  with  the  position  of  the 
cross-section.  In  most  cases  it  is  more  than  45°,  and  may  reach 
75°,  especially  near  the  outcrop,  but  in  depth  it  shows  a  decided 
tendency  to  flatten,  and  in  the  deeper  mines  the  average  dip  is 
probably  slightly  less  than  30°.     The  typical  "  banket  "  is  com- 


& .  & 


^  P 


^ 


Scale   of  Feet 

O  IOO        ZOO       300        400        500 


Fig.  147.     Section  showing  Faulting  of  Main  Reef  (Hatch). 

posed  of  fairly  well  rounded  pebbles  and  small  boulders  of  quartz 
and  quartzite  of  an  average  diameter  of  perhaps  1  to  2  inches, 
together  with  more  angular  and  elongated  fragments  of  slate  and 
chert.  Becker6  has  concluded  from  the  general  shape  and  dis* 
position  of  the  pebbles  that  they  were  deposited  on  marine  beaches, 
and  are  not  river-laid  conglomerates.  The  pebbles  are  embedded 
in  a  siliceous  cement  made  up  of  quartz  grains  that  are  themselves 
cemented  by  siliceous  impregnations,  making  a  mass  so  compacted 
that  fracturing  takes  place  often  with  greater  ease  across  than 
around  the  pebbles. 


°  Hatch,  Trans.  Geol.  Soc.  S.A.,  VII,  1905,  p.  58. 

6  18th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  V,  1897-  p.  160. 


446  AFRICA. 

The  gold  occurs  in  the  siliceous  cement  in  exceedingly  fine, 
irregular,  angular  particles  rarely  visible  to  the  naked  eye.  It  is 
often  associated  with,  and  is  found  resting  on,  crystals  of  pyrite. 
In  many  cases  rounded  particles  of  pyrite  may  be  bounded  by  gold 
particles.  The  rounded  grains  and  small  masses  of  pyrite  are  of 
interest,  since  they  simulate  rounded  water-worn  fragments,  and 
have,  indeed,  on  that  account,  given  rise  to  the  theory  of  a  placer 
origin  for  the  pyrite  as  well  as  for  the  gold  of  the  banket.  No 
original  gold  grains,  or,  to  be  precise,  only  a  few  exceedingly  minute 
particles,  have  been  found  within  the  pebbles  of  the  conglomerate, 
though  numerous  instances  are  recorded  of  secondary  auriferous 
deposition  along  fracture  planes  within  the  pebbles. 

Pew  questions  relating  to  the  deposition  of  gold  have,  of  late 
years,  been  more  keenly  discussed  than  the  origin  of  the  gold  of  the 
Witwatersrand  conglomerate.  Various  theories  have  from  time  to 
time  been  advanced  to  account  for  its  widespread  presence  through- 
out the  cement  of  the  conglomerate  in  such  relatively  large  quan- 
tities. Of  these,  two  only  have  survived  and  alone  demand  con- 
sideration in  this  place.  The  first  is  the  hypothesis  of  placer 
origin,  which  assumes  that  the  gold  is  contemporaneous  in  deposition 
with  the  conglomerate,  and  that  it  has  its  representatives  in  modern 
auriferous  "  leads  "  and  gravels.  The  second  hypothesis  assumes 
that  the  gold  is  subsequent  in  deposition  to  the  conglomerate,  and 
that  it  was  introduced  by  percolating  siliceous,  and  possibly  also 
sulphide-bearing,  waters  ;  and  that  in  actual  mode  of  deposition 
it  differs  little  from  ordinary  fissure  vein  filling.  The  arguments 
for  the  placer  hypothesis  were  most  clearly  and  succinctly  set  forth 
by  Becker"  in  1897,  but  they  had  previously  been  advocated  by 
many  writers.  Of  late  years  they  have  been  resuscitated,  with 
certain  modifications,  by  Gregory, h  who,  in  order  to  account  for  the 
extreme  fineness  of  the  gold,  assumes  that  the  original  placer 
gold  has  been  dissolved  and  re-deposited  in  situ.  On  the  other  hand, 
the  impregnation  hypothesis  is  strongly  supported  by  the  majority 
of  those  geologists  who  have  had  the  inestimable  advantage  of 
having  been  brought  daily  into  contact  with  the  numerous  problems 
of  economic  geology  afforded  by  these  conglomerates.  The  case  for 
the  impregnation  hypothesis  is  outlined  by  Hatch  and  Corstorphine,c 
who  summarise  the  main  arguments  in  support  as  follows  :  — 

(1)  The  gold  is  practically  confined  to  the  matrix  of  the  con- 
glomerate occurring  there  in  association  with  other  minerals 
of  secondary  origin  ;   the  rare  cases  in  which  gold  occurs  in 

a  Loc.  cit.  sup. 

/(  Adv.  Sheets,  Trans.  Inst.  Min.  and  Met.,  1907. 

c  Loc.  cit.,  p.  14G. 


TRANSVAAL.  447 

the  pebbles  are  obviously  instances  of  infiltrations  along 
cracks,  a  fact  which  in  itself  lends  support  to  the  im- 
pregnation theory. 

(2)  It  occurs  in  crystalline  particles  often  surrounding  or  lying 

in  close  association  with  pyrite  crystals  or  marcasite 
concretions,  which  are  of  secondary  origin. 

(3)  It  is  uniformly  distributed  to  a  remarkable  degree. 

(4)  It  is  restricted  to  certain  definite  beds. 

While  there  is  therefore  much  to  be  said  on  both  sides,  the 
general  evidence  at  present  available  is  certainly  in  favour  of  the 
infiltration  hypothesis.  The  subject  has  been  dealt  with  as  fully 
as  possible  in  an  earlier  section  of  this  volume,  whither  the 
student  is  now  referred  for  further  details. 

Heidelberg  and  Klerksdorp. — The  Heidelberg  and  Klerks- 
dorp  goldfields  of  the  "  outside  "  districts  require  no  detailed  men- 
tion. The  gold  of  the  former  is  derived  almost  entirely  from  the 
Nigel  Reef  Series,  which,  as  has  already  been  seen,  is  the  extension 
in  the  southern  limb  of  the  Main  Reef  Series,  from  which  it  indeed 
differs  in  no  material  respect.  The  Klerksdorp  field,  on  the  other 
hand,  lies  on  the  northern  side,  or,  rather,  the  north-western  side 
of  the  syncline,  for  the  axis  of  folding  curves  here  southward.  Its 
mines  have  never  been  very  successful  ;  of  them  the  Buffelsdoorn 
has  been  the  most  productive.  The  reefs  are  greatly  disturbed  by 
diabase  dykes.  The  chief  auriferous  areas  are  those  of  Wolverand, 
Boscherand,  and  Buffelsdoorn.  The  pay-reef  of  the  last  has  been 
3  to  4  feet  wide.  In  this  case,  however,  gold  also  occurs  in  the  over- 
lying quartzite  in  streaks  associated  with  carbonaceous  and  pyritous 
seams.  The  Black  Reef  Series  has  been  extensively  worked  at 
Klerksdorp.  The  outcrop  of  banket  occurring  at  Venterskroon, 
between  Heidelberg  and  Klerksdorp,  is  auriferous,  but  is  extremely 
low  in  grade. 

Bloemhof. — In  the  extreme  south-west  of  the  colony  at  Bloem- 
hof  gold-quartz  has  been  found  in  the  banded  ironstone-schists  of 
rocks  that  are  probably  a  part  of  the  Swaziland  System.  The 
prospect  of  successful  mining  in  these  veins,  particularly  on 
Goudplatts  Farm,  was  favourably  regarded  in  1906.rt 

Pietershurg. — Of  similar  character  are  the  veins  of  the 
Pietersburg  district,  lying  towards  the  north  of  the  colony,  in  the 
area  formerly  known  as  the  Marabastad  goldfield.  These  have  been 
spasmodically  worked  for  many  years,  but  have  never  yielded 
any   mines   of   economic    importance.     The   veins   are   small   and 

a  Rep.  Transvaal  Mines  Dept.,  1906,  p.  54. 


448  AFRICA. 

erratic,  and  may  be  worked  only  by  individual  miners,  or  by  small 
companies.  The  country  is  the  Mount  Mare  schist  or  phyllite,  with 
which  is  well  developed  the  banded  hsematite-magnetite-quartz 
rock — the  "calico  rock"  of  the  miners — so  characteristic  of  the 
Swaziland  schists,  as,  indeed,  of  most  auriferous  Archaean  schistose 
areas.  A  huge  mass  of  auriferous  conglomerate  is  being  mined 
at  Haenertsburg,  east  of  Pietersburg. 

Zoutspansberg. — In  the  far  north  of  the  colony,  north  of 
the  Olifants  River,  is  the  Zoutspansberg  district,  including  the 
Murchison  and  Klein  Letaba  goldfields.  In  the  former  the  auriferous 
quartz  veins  occur  in  hornblende-  and  chlorite-schists.  Occasionally 
the  country  itself  is  impregnated  with  auriferous  pyrite.  Asso- 
ciated in  the  quartz  with  the  gold  are  stibnite  and  chalcopyrite. 
The  gold  content  of  the  veins  diminishes  notably  in  depth.  The 
Klein  Letaba  field  is  30  miles  further  north,  but  its  veins  are  in 
Swaziland  schists  similar  to  those  of  the  Murchison  Range.  The 
veins  are  parallel  to  the  foliation.  They  are  of  little  present  im- 
portance." 

Barberton.—  The  Barberton  (De  Kaap)  goldfields  are  by  far 
the  most  important  of  those  occurring  in  the  Swaziland  schists 
within  the  Transvaal.  They  lie  in  the  neighbourhood  of  Barberton 
in  the  east  of  the  Transvaal.  The  rocks  of  the  district  are  highly 
tilted  chloritic-schists,  sericite-schists,  argillites,  and  the  characteris- 
tic banded  ha?matite-magnetite-quartz  rock  that  stands  out  in  bold 
relief,  and  forms  the  serrated  mountain  ridges.  Representatives 
of  original  sedimentary  and  also  of  igneous  rocks  are  present.  The 
former  are  black  and  greenish  indurated  shales,  with  thin  beds  of 
pale  grey  quartzites.  Near  the  top  of  this  series  is  the  above- 
mentioned  banded  ferruginous  rock,  known  to  the  miners  of  Bar- 
berton as  "  bacon  rock."  The  igneous  rocks  are  mainly  sheared 
diabase,  obviously  intrusive  into  the  older  sedimentary  series.  The 
general  dip  of  the  foliation  is  northwards,  in  which  direction  the  schists 
give  place  to  a  granite  or  to  a  diorite.  Veins  appear  to  have  been 
formed  for  the  most  part  along  shear-zones.  At  the  Mount  Morgan 
mine,  12  miles  south-west  of  Barberton,  the  auriferous  zone  is  made 
up  of  small  stringers  of  grey  quartz  lying  in  a  sheared  belt  in  the 
softer  shales,  near  the  laminated  "  bacon  rock."  Pyritous  impreg- 
nation of  the  country  is  common,  but  occurs  seldom  in  the  quartzites 
and  frequently  in  the  black  shales. b 


a  Steuart,  Trans.  Inst.  M.E.,  1900,  XVII,  p.  338  ;    Bordeaux,  Ann.  des  Mines,  XIV, 
1898,  p.  95  ;   Merinsky,  Min.  Jour.,  1905,  p.  629. 

"  Kynaston,  Rep.  Geol.  Surv.  Transvaal,  1905,  p.  61. 


TRANSVAAL. 


449 


The  Sheba,  north-east  of  Barberton,  has  always  been  the  most 
prominent  of  the  Barberton  mines.  Its  vein-zone  has  an  average 
width  of  120  feet,  and  is  continuous  along  the  strike  for  a  great  dis- 
tance. The  pay-ore,  however,  is  restricted  to  shoots.  The  main 
Sheba  shoot  is  300  feet  long,  and  has  been  worked  for  1,200  feet  on 


Fig.  148.     Enrichment  near  Contact  of  Fracture  and  Chert 
Vein,  Zwartkopje  Mine,  Barberton    ( Weldon). 

its  pitch.  Mineralisation  in  the  case  of  the  Sheba  zone  appears 
to  have  taken  place  along  and  beneath  the  footwall  contact  of  a 
quartzite  bed  with  an  underlying  slate,  the  latter  having  been 
silicified    and   impregnated  for  some   depth  below  the   quartzite. 

El 


450  AFRICA. 

This  selective  silicification  was  possibly  due  to  the  relative  per- 
meability of  the  two  beds,  but  much  more  probably  arose  from  the 
greater  tendency  of  the  less  siliceous  stratum  to  undergo  metaso- 
matic  replacement  by  siliceous  waters.  Recent  workings,  as  shown 
in  the  accompanying  section,  have  been  carried  on  in  the 
neighbourhood  of  fractures  from  whence  impregnation  has 
proceeded. 

On  Moodie's  Range,  south-west  of  Barberton,  well-defined 
fissure  veins  occur  in  chloritic  and  sericitic  schists,  intruded  by 
dioritic  or  diabasic  dykes.  The  principal  veins  are  the  Ivy  and  the 
Pioneer,  both  occurring  along  fault-planes.  The  gold  is  found  in 
well-defined  shoots  in  massive  white  quartz. a 

An  outlying  auriferous  area  of  no  present  economic  value  is  the 
Komati  Goldfield  at  Steynsdorp,  south  of  Barberton.  The  veins 
of  this  field  are  also  in  the  Swaziland  schists.  They  are  small,  and 
have  given  rich  outcrop  yields  that  have  not  continued  in  depth. 
An  auriferous  quartz  vein  occurs  in  the  quartzites  of  the  Black 
Reef  Series  (the  conglomerates  of  which  are  also  at  times  slightly 
auriferous)  at  Kromdraai,  ten  miles  north  of  Krugersdorp.^ 

The  gold  yield  of  the  Pretoria  district  proper  for  1907,  viz., 
266  ounces,  was  derived  from  a  small  gold-quartz  vein  in  the 
Pretoria  quartzites,  30  miles  west  of  the  capital. 

Malmani. — Auriferous  deposits  in  the  great  Dolomite  Forma- 
tion that  underlies  the  Pretoria  Series,  occur  both  in  the  west  and 
in  the  east  of  the  colony.  The  locus  of  the  former  occurrence  is 
Malmani,  20  miles  north-east  of  Mafeking.  Its  gold-quartz  veins 
strike  with  the  formation,  but  dip  vertically.  The  veins  are  filled 
either  with  quartz  or  with  a  brecciated  dolomite  cemented  by 
quartz.  Tremolite  frequently  occurs  as  a  gangue  mineral.  The 
numerous  carbonates  and  oxides  found  indicate  the  presence  of 
blende,  galena,  chalcopyrite,  and  pyrite  in  depth,  but  the  veins, 
owing  to  the  great  quantities  of  water  met  with,  have  not  been 
worked  to  greater  depths  than  100  to  150  feet/ 

Lydenburg. — The  Lydenburg  (Pilgrim's  Rest)  goldfields  lie 
on  the  High  Veldt  in  the  east  of  the  Transvaal  in  or  near  the  great 
more  or  less  meridional  escarpment  of  the  northern  Drakensberg, 
here  2,000  feet  in  height.  They  are  among  the  oldest  goldfields 
in  the  Transvaal,   their  placer  deposits  having  been    discovered 


a  Bordeaux,  Ann.  des  Mines,  XI,  1897,  p.  296;    Krause,  Zeit.  fur  prakt.  Geol., 
1897,  p.  22. 

6D6rffel,  Trans.   Geol.  Soc.   S.A.,  VI.   1904,  p.   101. 

c  Hatch,  Trans.  Geol.  Soc.  S.A.,  VII,  1905,  p.  3. 


to 


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TRANSVAAL. 


451 


as  early  as  1868,  or,  according  to  another  authority,  in  1870.  It  is 
estimated  that  gold  to  the  value  of  nearly  half-a-million  pounds 
sterling  was  obtained  from  the  alluvial  in  the  earlier  years  of  the 
field.  The  placer  deposits  are  now  almost  exhausted,  but  the  ore- 
bodies  from  whence  the  alluvial  gold  had  been  derived,  furnish  from 
year  to  year  a  fairly  regular  yield  of  gold. 

The  Swaziland  schists  and  granites  lie  along  the  foot  of  the  great 
escarpment,  some  12  miles  east  of  Pilgrim's  Rest.  They  are  overlain 
unconformably  by  the  beds  of  the  Transvaal  System,  as  shown  in 
the  subjoined  table,  in  which  the  uppermost  beds  are  the  youngest : — a 


Megaliesberg  Quartzites 

Shales  with  intrusive  igneous  sheets 

Daspoort  Quartzite  Series 

Shales  with  intrusive  igneous  sheets 

Timeball  Hill  Quartzite  Series .  . 

Shales  with  intrusive  rocks   .  . 

Dolomitic  Limestone  and  Chert 

Thin  band  of  Quartzite 

Dolomitic  Limestone  and  Chert 

Shaly  Sandstones 

Quartzites  and  Sandstones     .  . 

Shaly  Sandstones 

Quartzites  and  Sandstones     .  . 

Older  Granite 


Pretoria 
Series. 


Dolomite 
Series. 

Black 

Reef 

Series. 


r  Transvaal  System. 


/ 


Swaziland  System. 


Diabasic  igneous  rocks  are  abundant,  and  occur  both  as  vertical 
dykes  traversing  the  nearly  horizontal  members  of  the  Transvaal 
System,  and  also  as  sills  or  sheets  intercalated  in  the  strata.  It  is 
notable  that  elsewhere  in  the  colony  diabasic  intrusions  are  rare  in 
the  Dolomite  Series. b  In  addition  to  the  diabase,  diorite  andgabbro 
also  occur.  Auriferous  horizons  are  found  both  in  the  Black  Reef 
and  in  the  Dolomite  Series.  Those  of  the  former,  though  rich  near 
the  outcrop,  do  not  continue  to  carry  gold  when  driven  on,  and  are 
of  no  present  economic  importance.  In  the  Dolomite  Series,  however, 
there  are  several  horizons  at  which  rich  ore-bodies  have  been  developed. 
These  reefs  are  practically  horizontal,  their  dip,  when  they  possess 
any,  being  to  the  west  at  5°  to  7°.  They  appear  to  be  siliceous 
replacements  of  interbedded  dolomitic  limestones,  and  as  such  are 
analogous  to  those  described  elsewhere  in  this  volume  from  Rico, 
Colorado,  and  from  Mercur,  Utah. 

The  two  principal  reefs  near  Pilgrim's  Rest  are  the  Upper 
Dolomite,  or  Theta  Reef,  and  the  Lower  Dolomite,  or  Beta  Reef. 
The  former  is  on  an  horizon  100  feet  below  the  base  of  the  Pretoria 
Series  ;  the  latter  is  300  feet  below  the  Theta  Reef.  About  20  feet 
above  the  Theta  Reef  is  a  sheet  of  diabase  from  20   to   60  feet  in 


a  Hall,  Rep.  Geol.  Surv.  Transvaal,  1906,  p.  75. 
6Thord-Gray,   Trans.    Geol.    Soc.   S.A.,   VIII,    1906,   p.    67. 


452 


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Plate   XXIII. 


'^fe  .*>:.,;■■;■   ", 


2    ** 


Theta   Reef,  Clewer  Mine,  Pilgrim's  Rest. 
(Transvaal  Geological   Survey.) 

(Thickness  of  reef:  from  feet  of  figures  to  hammer-head  ;    Dolomite  and  Chert 

series  overlying.) 


TRANSVAAL.  453 

thickness,  which  overlies  almost  directly  a  thin  quartz  seam  known 
as  the  "'  indicator."  The  same  relation  of  auriferous  horizon  to 
diabase  sheet  is  observable  in  the  case  of  the  Beta  Reef,  where  the 
diabase  sill  is  only  some  10  feet  overhead  and  the  intervening  space 
is  occupied  by  black  earthy  manganese  ores  underlain  by  chert. 
The  already  mentioned  veins  in  the  Black  Reef  Series  are  likewise 
associated  with  diabase  sills. 

The  Theta  Reef  varies  in  thickness  from  an  inch  or  two  to  12 
to  15  feet.  Where  thickest  it  has  often  been  richest.  Since  it  is 
nearly  horizontal,  it  has  been  worked  on  a  longwall  system,  similar 
to  that  employed  in  blocking  out  flat  coal  seams.  In  places  the 
Theta  Reef  was  very  rich,  assaying  more  than  50  ounces  gold  per  ton. 
The  length  of  the  outcrop  of  the  Theta  Reef  along  its  strike  is  at  least 
20  miles,  while  those  of  the  various  reefs  in  the  Dolomite  Series  taken 
together  are  estimated  by  Thord-Gray  to  reach  90  miles.  The  pay- 
ore  is  whitish-yellow  to  rusty-brown  quartz.  As  is  evidenced  by 
the  honeycombed  and  cellular  character  of  the  quartz  pyrite  was 
formerly  present  in  some  quantity.  The  vein  occasionally  becomes 
earthy  in  character,  a  feature  considered  to  be  indicative  of  high 
values.  The  principal  mines  working  on  these  reefs  are  the 
Clewer,  Peach  Tree,  Theta,  and  Jubilee  on  the  Theta  Reef  ;  and 
the  Beta,  Chi,  and  Psi  on  the  Beta  Reef.  The  Clewer  mine  has 
been  the  most  productive. 

Twenty  miles  south  of  Pilgrim's  Rest  is  the  Glynn's  Lydenburg 
mine,  situated  on  the  Sabie  river.  The  geological  features  are  here 
similar  to  those  at  Pilgrim's  Rest.  Two  auriferous  horizons  are 
known  in  the  Dolomite  Series,  of  which  the  upper  reef,  150  feet 
above  the  Kantoor  sandstone,  is  the  more  important.  It  is  about 
12  inches  thick  and  consists  of  a  series  of  quartz  layers  separated 
by  partings  of  impure  brown  limonite.  Visible  gold  is  rare.  One  of 
the  most  characteristic  features  in  connection  with  the  ore-body  is 
the  presence  of  a  chert  band  18  inches  below  the  footwall  of  the  reef, 
the  intervening  rock  being  composed  mainly  of  brown  earthy 
limonite.  The  average  assay  value  of  a  portion  of  the  reef  was 
38  dwts.  gold  over  a  thickness  of  15  inches. 

Somewhat  similar  auriferous  occurrences  are  those  of  Barrett's 
Berlyn  and  Coetzestroom.  The  denudation  of  these  and  similar 
ore-bodies  furnished  the  placer  gold  of  Mac-Mac,  Kaapsche  Hop,  and 
Spitzkop.  At  the  Duivel's  Kantoor  they  furnished  particles  and 
large  masses  of  highly  crystalline  gold,  the  latter  varying  in  weight 
from  1  dwt.  to  50  ounces.  The  gold  was  associated  with  quartz 
and  with  pseudomorphs  of  limonite  after  pyrite.  The  gold  itself 
also  formed  encrusting  pseudomorphs  after  pyrite." 

a  Louis,  "  Ore  Deposits,"  London,  1896,  p.  737. 


454  AFRICA. 

A  little  placer  gold  has  been  obtained  in  the  Kaap,  Queen's, 
and  Crocodile  rivers,  and  a  dredge  was  working  in  1907  below  the 
junction  of  the  Queen's  and  the  North  Kaap  rivers. 

At  Vryheid  a  little  alluvial  gold  has  been  obtained.  It  results 
from  the  degradation  of  "  banket "  reefs  of  the  Witwatersrand  type.™ 

Swaziland. — The  Swaziland  Protectorate  has  produced  a  con- 
siderable amount  of  gold,  mainly  from  Forbes  Reef,  east-north-east 
of  Steynsdorp,  and  from  the  MacLachlan  and  Pigg's  Peak  mines, 
south-west  of  Barberton,  and  across  the  boundary  from  the 
Transvaal.  The  first-named  is  a  low-grade  open-quarry  mine  in 
slates  traversed  by  auriferous  quartz  veins.  Its  tenor  is  only  3 
to  4  dwts.  per  ton.  To  1896  it  had,  nevertheless,  produced 
36,000  ounces.  The  Pigg's  Peak  occurrence,  lying  south-east  of 
Barberton,  is  in  an  impregnated  quartzitic  rock,  and  at  times  yields 
rich  chimneys  and  pockets.  In  1890,  60  tons  yielded  3,000  ounces, 
but  the  general  tenor  is  certainly  less  than  half  an  ounce.  The 
MacLachlan  Reef  lies  in  schists  veined  with  quartz. h 

During  1906-1907  the  gold  yield  of  Swaziland  was  2,166  ounces. 


NATAL. 

Gold-mining  is  of  little  present  importance  in  Natal.  Small 
gold-quartz  veins  have  from  time  to  time  been  found,  and  have  given 
pockets  at  the  surface  that  have  raised  hopes  of  permanence  in  depth 
— hopes  that  have  never  been  realised. 

Natal  is  divided  for  administration  purposes  into  four  mining 
districts.  In  the  Northern  district  gold  is  found  along  the  Pongola 
river.  The  Pongola  goldfield,  east  of  Paulpietersburg,  as  well  as 
the  small  goldfield  on  the  Mona  tributary  of  the  Black  Umfulosi, 
is  in  a  conglomerate  or  "banket"  formation,  very  similar  to  that 
of  Witwatersrand.  Similar  gold  occurrences  are  noted  from  the 
Insuzi  Valley,  and  from  the  neighbourhood  of  Melmoth  to  the 
east.c  They  were  widely  prospected  about  1895,  but  without 
result.  At  the  Nondweni  goldfield  on  the  White  Umfulosi,  and 
also  near  Melmoth,  gold-quartz  is  found  in  Archaean  schists. 

In  the  Eastern  district,  "  banket  "  reefs  occur  in  the  Nkandhla 
district  between  the  White  Umfulosi  and  the  Tugela  rivers.  Gold- 
quartz  veins  are  found  in  the  crystalline  schists  that  flank  the 
granites  in  the  neighbourhood  of  Nkandhla.  The  principal  auriferous 


a  Denny,  Trans.  Aust.  Inst.  M.E.,  III.,  1896,  p.  88. 

b  Bordeaux,  Ann.  des.  Mines,  XI,  1897,  p.  299. 

c  Hedges,  Rep.  Mines  Dept.  Natal.  1903,  p.  41  ;  Anderson.  2nd  Rep.  Natal  Geol. 
Surv.,  1904,  p.  134. 


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NATAL.  455 

areas  in  the  foregoing  districts  are  Upper  Insuzi,  Lower  Insuzi, 
Vungwini,  Melmoth,  and  Eshowe.  At  Signal  Hill,  close  to  Eshowe, 
wire-gold  has  been  found  in  the  schists. 

In  the  South-western  district,  at  Chaka's  Kraal,  reefs  occur  in 
Palaeozoic  sandstones."  These  veins  were  rich  at  the  surface,  but 
gave  out  in  depth.  Near  Chaka's  Kraal  a  slightly  auriferous  con- 
glomerate has  been  found,  which  did  not  yield  anything  of  promise 
on  further  prospecting.  The  veins  of  the  Umzinto  goldfields 
traverse  schists  and  gneisses  of  the  Swaziland  Series.  The  quartz 
was  pyritous,  but  carried  free  gold  near  the  surface.  The  veins 
were  extremely  irregular  in  extension  and  content.  A  crushing 
made  in  1892  yielded  about  29  ounces  from  60  tons  quartz.  The 
field  is  now  abandoned.  The  small  Dumisa  goldfield  in  the  south 
was  in  1907  the  only  gold-producing  field.  In  that  year  it  yielded 
about  800  ounces. 

Natal  in  1904  produced  no  gold.  In  1905  its  yield  was  only 
108  ounces,  and  in  1906  some  73  ounces. 


GERMAN    SOUTH-WEST    AFRICA. 

Gold  is  known  in  trifling  quantities  from  many  widely  separated 
water-channels  in  German  South-west  Africa.  Its  principal 
occurrences  are,  however,  in  veins  associated  with  sulphides.  It 
has  been  reported  from  the  Lower  Kuisib  (near  Walfisch  Bay), 
associated  with  bismuth  and  wolfram.6  Voit,c  however,  failed  to 
find  bismuth  or  wolfram  in  the  so-called  wolfram-bismuth  veins  of 
Usis.  Gold  is  widely  distributed  with  copper  sulphide  in  the 
amphibolitic  members  of  the  metamorphic  schists  and  gneisses 
(Namaqualand  schists),  which  are  the  dominant  rocks  of  the 
country.  These  auriferous  occurrences  are  situated  at  Hussab, 
on  the  right  bank  of  the  lower  Swakop  ;  at  the  Pot  mine,  further 
up  the  Swakop  ;  and  in  the  neighbourhood  of  Otyikango  (Barmen), 
far  up  the  Swakop  near  Windhoek.  Kuntz^  found  near  Rehoboth, 
south  of  Windhoek,  samples  of  copper-ore  giving  62  per  cent, 
copper  and  11  dwts.  gold  per  ton.  The  amount  of  ore  available 
was  trifling.  In  other  auriferous  veins,  the  gold-content  is  much 
less,  being  generally  about  2  dwts.  per  ton.  The  free  gold  found  at 
the  outcrops  of  the  veins  is  itself  due  to  decomposition  of  the  pyrites, 
and  to  secondary  surface  enrichment,  since  even  the  low  tenors  noted 
decrease  materially  with  increase  of  depth. 


"Anderson,   1st  Ann.   Rep.  Natal  Geol.  Surv.,   1901,  p.  92. 
b  Macco,  Zeit.  fiir  prakt.  Geol.,  XI,  1903,  p.  30. 
c  Trans.  Geol.  Soc.  S.A.,  VII,  1905,  p.  88. 
d  Trans.   Geol.  Soc.   S.A.,  VII,   1905.   p.   74. 


456  AFRICA. 


CAPE    COLONY. 


Traces  of  gold  occur  in  several  places  within  the  limits  of  Cape 
Colony.  An  interesting  occurrence  of  gold  is  from  near  Craddock, 
where  it  is  associated  with  prehnite  in  nests  in  volcanic  rocks. a 
Auriferous  veins  have  also  been  reported  from  this  neighbourhood. 

Two  well-known  occurrences  of  more  than  mineralogical  im- 
portance are,  however,  those  of  the  Millwood  goldfield,  Knysna 
district,  and  the  Prince  Albert  goldfield  further  north  across  the 
Olifants  River  and  the  Zwarte  Bergen.  The  former  lies  in  the 
Outeniqua  Mountains,  very  near  the  south  coast  of  the  colony.  Its 
gold-quartz  veins  traverse  both  the  Table  Mountain  sandstones 
and  the  conformably  overlying  slates. h  In  the  latter,  the  veins  are 
massive  and  continuous,  containing  pyrite  and  chalcopyrite.  They 
are  parallel  to  the  strike  of  the  beds,  and  dip  in  the  same  direction, 
but  at  a  slightly  greater  angle.  In  the  sandstone  the  veins  are  much 
more  variable  in  size  and  extension.  The  quartz  of  the  Table 
Mountain  sandstone  contains  gold,  pyrite,  blende,  galena,  and  some- 
times carbonate  of  iron.  The  mineral  content  of  these  veins  would 
appear  to  have  been  derived  from  a  bed  of  auriferous  conglomerate 
that  occurs  near  the  top  of  the  Table  Mountain  series  in  the  imme- 
diate vicinity.  Assays  of  this  conglomerate  have  given  as  much  as 
2  dwts.  per  ton.  It  is,  however,  exceedingly  hard  and  indurated. 
It  dips  under  the  Bokkeveld  slates  reappearing  on  the  other  side  of 
the  syncline.c  From  the  proclamation  of  the  fields  in  1887  to  March, 
1905,  3,370  ounces  had  been  registered  as  coming  from  the  placer 
deposits  derived  from  the  above-described  veins.  Schwartz  con- 
cludes with  some  justice,  that  the  nuggets  have  grown  in  situ,  and 
have  not  been  derived  as  such  from  the  reefs.  Alluvial  gold  occurs  in 
the  Poverty  Flats,  an  old  river  gravel,  and  also  in  both  the  rivers 
draining  the  Millwood  area,  viz.,  the  Gowkamma  (Homtini)  and 
the  Knysna. 

The  Prince  Albert  goldfield  is  entirely  a  placer  field.  The  first 
nugget  was  picked  up  there  in  1871.  It  weighed  2|  ounces,  and  was 
found  among  the  earth  that  had  been  thrown  out  by  an  aardvaark 
digging  a  hole.  In  1891  another  nugget  of  7  dwts.  was  found,  and 
the  area  was  then  proclaimed  a  goldfield.  The  yield  was,  however, 
very  small,  only  504  ounces  having  been  obtained  to  the  end 
of  the  year  1891.  The  gold  area  is  itself  on  the  Karroo  formation,  one 
that,  so  far  as  is  known,    carries  no  gold-veins.     It  is,  therefore, 

a  Louis,  Jour.  Min.  Soc,  X,  1893,  p.  245. 

6  Schwartz,  Trans.  Phil.  Soc.    S.A.,  XV,  1904,  p.  43  ;   Id.,  Geol.  Mag.,    Dec,   V,  II, 
1905,  p.  369  ;    Sawyer,  Parliamentary  Rep.,  Cape  Colony,  G.  45,  1893. 

c  Schwartz,  Geol.   Mag.   cit.   sup.,  p.   375. 


CAPE     COLONY.  457 

considered  probable  that  the  gold  has  been  originally  derived  from 
the  Table  Mountain  sandstone  of  the  Zwarte  Bergen  to  the  south, 
from,  indeed,  such  auriferous  conglomerates  as  have  been  described 
as  occurring  in  the  Knysna  area.a 

Rogers  b  records  the  finding  of  a  solitary  nugget  of  gold  in  the 
Witteberg  (Cape)  beds  at  Kragga  Poort,  near  Constable. 

Cape  Colony  produced  98  ounces  gold  in  1905,  and  291  ounces  in 
1906. 


a  Schwartz,  Trans.  Phil.  Soc.  S.A.,  XV,  1904,  p.  56. 
""Geology  of  Cape  Colony,"  London,  1905,  p.  145. 


458 


NORTH   AMERICA. 


BRITISH  NORTH  AMERICA.— NEWFOUNDLAND. 

Several  auriferous  localities  are  marked  on  the  large-scale  map 
of  Newfoundland,  issued  by  the  Geological  Survey  Department  of 
that  islands  The  Rose  Blanche  gold-quartz  veins  are  on  the  south 
coast,  30  miles  east  of  Cape  Ray.  They  are  of  great  size,  but  are  low- 
grade.  The  country  of  the  veins  is  of  Laurentian  age,  and  granites 
are  intrusive  in  the  neighbourhood.  Twenty  miles  further  east, 
and  still  near  the  coast,  are  the  bornite  deposits  of  Cinq  Cerf ,  which, 
near  the  surface,  contained  free  gold  in  very  coarse  flakes.  The 
deposit  is  not  now  worked. 

The  gold  yield  of  Newfoundland  is  at  present  confined  to  that 
recovered  as  a  by-product  from  the  important  copper-ores  of  Tilt 
Cove,  Baie  Verte,  York  Harbour,  &c,  containing  about  1-5  dwts. 
gold  per  ton.  On  this  basis  the  total  annual  yield  of  Newfoundland 
is  estimated  at  between  6,000  and  7,000  ounces  fine  gold.&  The 
rocks  of  the  district  form  a  complex  of  metamorphosed  Archaean 
serpentines,  diorites,  and  dolerites,  through  which  granite  is  intrusive. 
Veins  in  similar  rocks  were  worked  during  1906  for  their  gold  content 
at  Goldenville  on  Ming's  Bight,  between  White  Bay  and  Notre 
Dame  Bay,  in  the  north  of  the  island.  No  crushings  have  as 
yet  been  made  from  Goldenville,  but  tests  show  a  value  of  44s.  6d. 
($10.68)  per  ton.  At  Sopp's  Arm,  near  the  head  of  White  Bay, 
auriferous  veins  occur  near  the  junction  of  Silurian  and  Cambro- 
Silurian  rocks.  Through  the  latter,  basic  igneous  rocks  are  intrusive. 
The  veins  have  been  worked  on  a  small  scale,  but  were  abandoned 
in  1905,  when  their  tenor  had  fallen  to  3  dwts.  per  ton. 


DOMINION  OF  CANADA. 

The  history  of  gold  in  Canada  is  almost  entirely  confined  to  the 
second  half  of  the  nineteenth  century.  Though  the  gold  of  the 
Chaudiere  region  in  Quebec  was  known  as  far  back  as  1823,  it  was 
only  with  the  alluvial  discoveries  of  the  Cariboo  district  in  British 
Columbia  in  1857,  and  the  opening  of  the  gold-quartz  mines  of  Nova 
Scotia  in  1860,  that  Canada  may  be  said  to  have  entered  the  ranks 

"  Howley,  Toronto,  1907  ;  Scale,  1  inch  =   G-9  miles. 

&  Howley,  Min.  Statist.  Newfoundland,  St.  Johns,   1905,  p.  .18. 


CANADA. 


459 


of  gold-producing  countries.  Broadly  speaking,  the  placer  and  the 
vein  deposits  of  Canada  are  well  separated.  Of  the  former  only- 
three  are  of  importance,  and  these  all  lie  in  the  far  west,  or  the  far 
north-west,  of  the  Dominion,  and  on  the  Pacific  slope  of  the  con- 
tinent. All  three,  Klondyke,  Atlin,  and  Cariboo,  present  the  same 
general  features.  The  richer  gravels  are  Tertiary.  The  deposits 
of  the  latter  two  have  been  profoundly  affected  by  glacial  agencies, 
sometimes  suffering  erosion  from  the  ice-sheet,  sometimes  being 
buried  deep  below  glacial  debris.  The  Canadian  vein-deposits 
lie  also  in  three  main  regions  ;  in  southern  British  Columbia,  where 
they  owe  their  origin  to  the  Upper  Mesozoic  and  Lower  Tertiary 
vulcanicity  that  has,  further  south,  given  so  many  rich  gold,  silver, 
and  copper  fields  to  the  Western  United  States  ;  in  Ontario,  where 
they  may  be  said  to  mark  the  northern  limit  of  the  great  Appalachian 
metalliferous  belt  ;  and  in  Nova  Scotia,  where  they  present  a 
remarkable  vein  type,  paralleled  only  on  the  Bendigo  goldfield  of 
Australia.  The  western  vein-deposits  have  also  been  markedly 
affected  during  the  glacial  epoch.  If  ever  they  possessed  zones  of 
surface  enrichment,  and  that  such  was  the  case  is  at  least  doubtful, 
these  have  disappeared  before  the  great  ice-plane.  The  outstanding 
feature  of  Canadian  ore-bodies — a  feature  that  must  be  due  largely 
also  to  post-glacial  climatic  conditions — is  therefore  their  lack  of 
secondarily  enriched  oxidation  zones. 

The  gold-yield  of  Canada  from  the  year  1895,  when  the  Yukon 
fields  were  discovered,  is  shown  below. a 

GOLD  PRODUCTION  OF  CANADA. 


Year. 

Fine  Ounces. 

Value,  Dollars. 

Value,  Sterling. 

1895 

100,806 

$2,083,674 

£427,153 

1896 

133,274 

2,754,774 

564,729 

1897 

291,582 

6,027,016 

1,235,538 

1898 

666,445 

13,775,420 

2,823,961 

1899 

1,028,620 

21.261,584 

4,358,625 

1900 

1,350.176 

27.908.153 

5.721,171 

1901 

1.167,320 

24,128.503 

4,946,343 

1902 

1,032,253 

21,336.667 

4,374,017 

1903 

911.639 

18,843,590 

3,862,936 

1904 

796.445 

16.462,517 

3,374,816 

1905 

700,863 

14.486.833 

2,969,801 

1906 

581.709 

12,023.932 

2,464.906 

1907 

401.000* 
9.162,132 

8,264,765 

1,704.276 

$189,357,428 

£38,828,272 

*  Estimated. 


a  Ann.  Rep.  Geol.  Surv.  Canada,  1904,  p.  8;   Min.  Industry,  1906,  p.  886. 


460 


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O 

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461 


NOVA  SCOTIA. 

The  auriferous  rocks  of  Nova  Scotia  are  confined  to  a  broad 
belt  lying  along  the  south  or  Atlantic  coast,  not  only  of  the 
mainland,  but  also  of  Cape  Breton.  In  the  latter  division, 
however,  they  reach  as  far  north  as  Whycocomagh,  north  of 
Bras  d'Or  Lake,  and  are,  moreover,  in  strata  of  greater  age  (pre- 
Cambrian)  than  those  of  the  mainland.  The  earliest  recorded 
discovery  of  gold  in  Nova  Scotia  occurred  in  1860,  and  appears  to 
have  been  another  of  the  direct  results  of  the  world-wide  pros- 
pecting engendered  by  the  great  gold  discoveries  in  California  in 
1849,  and  in  Australia  in  1852.  The  gold-quartz  veins  first  worked 
were  those  of  Tangier,  on  the  coast  some  40  miles  east  of  Halifax. 

The  auriferous  zone  of  the  mainland  extends  from  Cape  Canso 
in  the  east  to  Bear  Cove  and  Cape  St.  Mary  on  the  west,  a  distance 
of  280  miles.  Its  greatest  width  across  the  strike  of  its  stratified 
rocks  is  75  miles,  along  a  line  south-east  from  the  head  of  St.  Mary's 
Bay,  in  the  extreme  west  of  the  peninsula.  The  average  width  of 
the  auriferous  zone  is  much  less,  and  may  be  taken  at  30  miles. 
Of  the  total  area,  quite  one-half,  or  some  3,000  to  3,500  square 
miles,  is  composed  of  granite,  which  is  practically  non-auriferous. 
The  remainder  of  the  region  is  occupied  by  a  single  series  of  sedimen- 
tary strata  referred  by  most  authorities  to  the  Lower  Cambrian, 
and,  indeed,  resembling  closely  the  Lower  Cambrian  bed-rock  of 
the  auriferous  alluvial  gravels  of  the  Chaudiere  in  Quebec. 

The  granite  is  younger  than,  and  was  intruded  into  the  sedimen- 
taries  towards  the  close  of  the  Silurian  (Oriskany).a  From  the 
highest  to  the  lowest  the  various  members  of  the  series  appear  to  be 
conformable.  Their  total  thickness  is  more  than  15,000  feet.  The 
series  has  been  named  by  Woodman  the  Meguma  Series.  Together 
with  other  geologists,  he  divides  the  beds  into  two  formations — 
an  upper,  about  4,000  feet  in  thickness,  made  up  almost  entirely  of 
dark-coloured  soft  slates,  and  termed  the  Halifax  formation,  and  a 
lower,  or  Goldenville  formation,  11,000  feet  thick,  composed 
mainly  of  quartzites,  but  containing  numerous  beds  of  slate  and  a 
few  conglomerates.  This  nomenclature  has  apparently  been  accepted 
by  Faribault,0  to  whom  the  greater  part  of  the  detailed  geological 
work  that  has  been  carried  on  in  Nova  Scotia  is  to  be  ascribed. 
The  Halifax  or  upper  formation  is  not  notably  auriferous.  All  the 
gold-quartz  veins  hitherto  worked  have  been  in  the  Goldenville 

a  Faribault,  Jour.  Canad.  Min.  Inst.,  II,  1899,  pp.  119,  162  ;    Id..  Mining  Soc.  Nova 
Scotia,  Halifax,  1900. 

b  Amer.  Geol.,  XXXIII,  1904,  p.  365. 

c  Loc.  cit.  sup.,  p.  369. 


462 


NORTH    AMERICA. 


formation,  and  more  especially  in  a  zone  about  5,000  feet  in  thickness, 
and  from  2,800  to  8,000  feet  below  the  base  of  the  Halifax  formation.0 
The  whole  Meguma  Series  has  been  thrown  into  a  series  of 
somewhat  sharp,  more  or  less  parallel,  folds  by  pressure  along  a 
meridional  or  a  north-west — south-east  line.  The  distance  between 
the  anticlinal  axes  varies  considerably,  but  an  average  distance 
appears  to  be  about  three  miles,  since  eleven  anticlines  occur,  for 
example,    in  a  distance  of  35  miles  between  Sheet  Harbour    and 


•   -'«^f     '.  '••'  -•••.  "'.    /   A/      v  .' /    —A  \ \i  \         ",  '>, 

'^-irftM^^^  M  I  I    fly  ygft  V  v-77 


Fig.   151.     Diagrammatic  Sectiok  across  Auriferous  Rocks  of  Nova  Scotia  (Faribault). 

Caledonia.  The  dips  of  the  strata  are  generally  from  75°  to  90°, 
and  are  rarely  under  45°.  The  anticlinal  axes  are  characterised  by 
the  occurrence  of  structural  elliptical  domes  of  varying  extent,  from 
which  the  strata  pitch  both  ways  on  the  strike.  These  domes  occur 
along  the  anticlinal  axes  at  distances  varying  from  10  to  25  miles, 
and  on  them  nearly  all  the  auriferous  districts  are  situated.  Of 
21  such  domes  mapped  by  Faribault  in  the  district  east  of  Halifax, 
no  less  than  1 4  have  been  worked  for  gold,  while  six  show  auriferous 
quartz,  and  the  remaining  dome  has  not  yet  been  proved. 

As  the  sedimentary  beds  were  being  folded,  a  considerable 
amount  of  slipping  and  sliding  took  place,  especially  at  the  contact 
between  beds  of  different  composition,  as  between  quartzite  (locally 
termed  "  whin  ")  and  slate.  A  section  across  an  anticlinal  axis 
will  therefore  show  the  various  beds  disposed  in  a  vertical  series  of 
super-imposed  parabolic  curves  with  intervening  spaces.  It  is  filling 
these  original  spaces  and  along  their  steeper  lateral  continuations 
that  the  Nova  Scotian  quartz  veins  have  been  developed.  Normally 
they  occur  between  slickensided  planes  of  contact  of  slate  and 
quartzite,  but  they  are  also  found  entirely  within  slate  beds  and, 
much  more  rarely,  entirely  within  beds  of  quartzite.  The  quartz 
veins  have  often  an  extension  in  strike  of  many  thousands  of  feet, 


0  Gilpin,  "  Minerals  of  Nova  Scotia,  "  Halifax,  1901,  p.  20. 


NOVA     SCOTIA. 


463 


while  they  have  been  worked  to  vertical  depths  of  700  feet.  They 
are  often  numerous  on  both  sides  of  an  anticlinal  axis.  At  Golden- 
ville  no  less  than  55  veins  are  known  to  the  north  of  the  axis  within  a 
width  of  1,300  feet,  while  50  occur  on  the  south  side  within  a  belt 
500  feet  wide.  The  Nova  Scotian  gold-quartz  veins,  are  therefore 
entirely  similar  in  form  to  the  more  famous  "  saddle  reefs  "  of  Ben- 
digo.  In  the  Salmon  river  district,  a  thick  vein  was  worked  on  the 
crest  of  the  anticline.  On  being  followed  down,  it  split  a  few  feet 
from  the  surface  into  two  "  legs,"  both  of  which  thinned  in  depth. 
Owing  probably  to  the  great  denudation  to  which  the  country  has 
been  subjected,  and  to  the  great  number  of  parallel  veins  exposed 


Fig.  152.     Roll  in  Nigger  Vein,  Tangier  (Packard). 

at  the  surface,  no  serious  attempt  has  as  yet  been  made  to  explore 
the  "  centre  country  "  after  the  Australian  fashion,  viz.,  by  sinking 
shafts  on  or  near  the  anticlinal  axis. 

Ordinarily,  the  veins  are  contact-bedded  veins,  but  cross  veins 
or  droppers  from  the  bedded  veins  (locally  termed  "'  angulars  ") 
are  met  with.  These  are,  as  a  rule,  parallel  with  the  strike,  but  cut 
across  the  dip  of  the  strata.  The  average  thickness  of  the  richer 
veins,  both  bedded  and  cross,  is  from  1  to  2  feet  only,  but  a  thickness 
of  15  feet  may  be  attained. 


464 


NORTH     AMERICA. 


By  far  the  most  remarkable  phenomenon  displayed  by  a  Nova 
Scotian  gold-quartz  vein  is  a  peculiar  crenulation  or  corrugation  of 
its  whole  width.  The  corrugation  varies  from  broad  open  folds  to 
close  overturned  ones,  and  the  degree  of  crumpling  may  be  said 
to  vary  inversely  as  the  thickness  of  the  vein.  The  cross  veins  are 
also  crenulated,  but  not  so  frequently  as  bedded  veins.  Corrugation 
is  also  less  frequent  in  veins  in  thin  bedded  quartzite  than  in  slate. 
It  never  occurs  in  thick  bedded  quartzites.  Where  the  corrugations 
are  well  marked  and  large,  the  terms  "  barrel  quartz  "  or  "  rolls  " 
are  used."  The  corrugations  then  present  the  appearance  of  a 
number  of  barrels  or  logs  of  wood  laid  side  by  side.  The  corru- 
gations are  normally  horizontal,  and  lie  with  their  length  parallel  to 


Fig.  153.     Crenulated  Quartz  Vein,  Moose  River  District,  Nova  Scotia. 

the  axis  of  the  anticline.  They  are,  however,  inclined  somewhat  to 
the  horizon  when  on  the  pitch  of  a  dome.  The  lamination  of  the 
adjacent  slates  follow  very  closely  the  corrugations  of  the  quartz 
vein.  Woodman  ^  maintains  that  the  phenomenon  is  certainly  not 
due  to  sliding  or  to  metasomatic  replacement,  and  believes  it  to 
arise  from  the  sinuous  course  of  the  fissures  in  which  the  quartz  has 
been  deposited.  Faribault,  on  the  other  hand,  supposes  the  corru- 
gations and  foldings  of  the  quartz  veins  to  be  due  to  the  differential 


°  Packard,  Min.  Sci.  Press,  Oct.  5,  1907. 

b  Proc.  Trans.  Nova  Scotia  Inst.  Sci.,  XI,  1903,  p.  67. 


NOVA     SCOTIA.  465 

movement  of  thick  beds  of  quartzite,  thus  crumpling,  curving, 
and  buckling  the  intervening  softer  slate  beds  with  their  contained 
quartz  veins. 

It  seems  at  least  to  be  certain  from  the  distortion  and  shearing 
of  the  pyrite  of  the  slates  that  mineralisation  was  complete  before 
general  metamorphism,  which  is  entirely  dynamic,  took  place. 
The  granites  of  the  region  took  no  part  in  the  formation  and 
mineralisation  of  the  quartz  veins,  which  were  formed  before  the 
igneous  intrusion. 

The  vein  matrix  is  always  quartz.  Pyrite,  chalcopyrite,  galena, 
and  blende  are  fairly  common  in  veins,  while  pyrite  and  arseno- 
pyrite  also  occur  in  the  country,  especially  in  the  slates.  Gold 
occurs  both  in  the  sedimentary  rocks  and  in  veins.  In  the  former 
it  is  found  rarely  in  the  "  whin  "  or  quartzite,  more  often  as  thin 
plates  in  slate.  In  veins  it  is  of  economic  importance  only  when  it 
occurs  in  "  shoots,"  or  "  pay-streaks,"  or  pockets.  Often  the  gold 
is  richer  in  the  "  rolls  "  or  swellings,  in  which  case  the  pay-streaks 
are  also  horizontal  or  slightly  inclined,  and  parallel  to  the  anticlinal 
axis.     The  pay-streaks  vary  in  width  from  20  to  60  feet.. 

Stibnite  and  native  antimony  veins  were  discovered  in  1880 
at  West  Gore,  Hants  County,  north-east  of  Halifax.  It  was  only 
after  the  stibnite  had  been  worked  and  exported  for  some  years 
that  its  auriferous  character  was  discovered. a  Most  of  the  gold 
is  free,  even  in  ore  assaying  10  ounces  per  ton.  The  veins  are  being 
worked  by  the  Dominion  Antimony  Company,  which  in  1905  shipped 
to  England  527  tons,  and  in  1906  782|  tons  antimony  ore,  obtaining 
therefrom  1,233  and  1,032  ounces  fine  gold  respectively. 

The  Cape  Breton  auriferous  occurrences  are  interesting  as 
occurring  in  rocks  older  than  those  of  the  mainland.  At  Middle 
River,  Whycocomagh,  and  Cheticamp  districts,  heavily  mineralised 
zones  occur  in  the  pre-Cambrian  schists.  In  1907  rich  ore  was 
found  in  the  first-named  district  by  the  Great  Bras  d'Or  Mining 
Company,  and  considerable  hopes  are  entertained  of  successful 
mining  in  these  rocks.  As  they  may  be  presumed  to  underlie  the 
rocks  of  the  mainland,  it  may  have  been  from  them  that  the  latter 
derived  by  ascending  solutions  their  metalliferous  content. 

At  Gay's  River  a  Lower  Carboniferous  conglomerate  overlying 
the  auriferous  slates  is  known  to  contain  gold,  and  has,  indeed,  been 
worked  on  a  small  scale.6 


a  Jour.  Min.  Soc.  Nova    Scotia,  VI,  p.  80 ;    Rep.  Dept.  Mines  Nova  Scotia,  1905, 
p.  69;    lb.,  1906,  p.  68. 

h  Becker,  U.S.  Geol.   Surv.,  18th  Ann.  Rep.,   1896-7,  Pt.  V,  p.  178  ;     Poole,  Proc. 
Trans.  Nov.  Scot.  Inst.  Sci.,  XI,  1904,  p.  236. 

Fl 


466 


NORTH    AMERICA. 


Alluvial  gold  exists  in  most  of  the  streams  flowing  over  or  from 
the  auriferous  vein  areas.  These  gravels  have  never  been  of  great 
economic  importance.  The  alluvial  gold  appears  to  have  been 
derived,  not  only  from  the  free  gold  of  the  above-described  veins, 
but  also,  and  particularly  in  the  Cape  Breton  pre-Cambrian  area, 
from  auriferous  pyrite  of  a  grade  too  low  to  warrant  working  under 
existing  circumstances.  A  remarkable  instance  of  wave  concentra- 
tion occurs  at  the  Ovens,  near  Lunenburg,  about  35  miles  west- 
south-west  of  Halifax.  Gold-quartz  veins  are  there  exposed  in 
cliffs  of  soft  easily-eroded  slates.  The  gold  derived  therefrom 
is  concentrated  by  wave-action  in  rifts  in  the  slate  shelves  formed 
by  denudation.  In  1861-2  no  less  than  2,500  ounces  were  thus 
recovered,  and  small  quantities  have  since  been  obtained  from  time 
to  time. 

The  principal  districts  now  being  worked  are  Mount  Uniacke, 
Renfrew,  Oldham,  Waverley,  and  Montagu,  all  near  Halifax,  to  the 
north  and  to  the  east  ;  Caribou,  Tangier,  Salmon  River,  Sherbrooke, 
Wine  Harbour,  and  Stormont,  towards  the  east  of  the  peninsula  ; 
and  Middle  River,  near  Bras  d'Or  Lake,  Cape  Breton. 

The  following  table  shows  the  gold  production  of  Nova  Scotia 
by  districts  between  the  years  1862-1905  inclusive.0 

NOVA  SCOTIA  GOLD  PRODUCTION,  1862-1905. 


Tons 

Total  Yield. 

Value. 

District. 

Crushed. 

Ounces. 

Sterling. 

v. 

Caribou  and  Moose  River,  from  1869 

179,090 

53,424 

£208,086 

Montagu 

28,939 

41,865 

163,063 

Oldham 

52,394 

56,139 

218,662 

Renfrew 

52,149 

44,991 

175,241 

Sherbrooke  (Goldenville) 

294,846 

152,055 

592,255 

Stormont 

305,795 

86,335 

336,273 

Tangier 

50,542 

23,922 

93,176 

Uniacke,  from  1866 

62,971 

43,438 

169,293 

Waverley 

155,520 

69,981 

272,574 

Brookfield,  from  1887 

92,754 

38,441 

149,729 

Salmon  River,  from  1883  . . 

118,440 

41,700 

162,420 

Whiteburn,  from  1887 

6.831 

9,758 

38,006 

Lake  Catcha,  from  1882     . . 

26,724 

26,352 

102,640 

Rawdon,  from  1887 

12,189 

9,606 

37,416 

Wine  Harbour 

70,205 

33,562 

130,723 

Fifteen  Mile  Stream,  from  1883    . 

36,456 

17,059 

66,444 

Malaga 

20,896 

19,294 

75,148 

Other  districts 

121,908 

66,782 

260,118 

1,688,649 

834,704 

£3,251,167 

a  Ann.  Mines  Rep.  Nova  Scotia,  1906,  "  Economic  Minerals,"  p.  15. 


NOVA    SCOTIA. 


467 


TOTAL  YIELD  OF  GOLD  OF  NOVA  SCOTIA  FROM  1862. 


Years. 

Crude  Ounces.* 

1862-1870   

177,549 

1871-1880 

133.058 

1881-1890 

196,067 

1891-1900 

237,048 

1901 

30,537 

1902   . 

28,279 

1903   . 

25,198 

1904 

14,280 

1905 

15,549 

1906 

14,079 

1907 

15,006 

Total. .  886,650  =  £3,452,500 

*  Average  value  per  crude  ounce,  £3-895  =  $19. 


NEW    BRUNSWICK. 


Alluvial  gold  in  small  quantities  has  been  found  in  several 
streams  in  New  Brunswick,  and  more  particularly  in  the  tribu- 
taries of  the  Tobique  and  the  Little  South-west  Miramichi 
rivers.  The  rocks  of  the  neighbourhood  are  Cambro-Silurian, 
underlain  by  quartzites,  slates,  and  glossy  phyllites  of  probable 
Cambrian  age.rt  No  auriferous  veins  have  as  yet  been  discovered 
in  this  neighbourhood,  but  from  the  resemblance  of  the  rocks  to 
those  of  the  Chaudiere  region  of  Quebec  and  to  those  of  Nova 
Scotia,  together  with  the  existence  of  alluvial  gold,  their  occurrence 
is  considered  probable.  Gold-quartz  veins  are,  however,  known 
further  south  at  St.  Stephen,  near  Woodstock,  where  they  occur 
in  graphitic  slate.  These  veins  are  apparently  of  no  economic 
importance.  At  Lauwigewank  certain  conglomerates,  are  slightly 
auriferous. b 

QUEBEC". 

The  gold-bearing  region  of  south-eastern  Quebec  (Eastern 
Townships)  lies  mainly  along  the  upper  waters  of  the  Chaudiere 
and  its  tributaries.  The  Chaudiere  joins  the  St.  Lawrence  from  the 
south  about  8  miles  above  Quebec.  Though  discovered  only 
some  80  years  ago  this  goldfield  is  the  oldest  in  Canada.  The  first 
gold  appears  to  have  been  obtained  in  1823  or  1824  near  the  mouth 
of  the  Gilbert  river.  Ten  years  later  a  nugget  weighing  2  •  2  ounces 
was  found  some  distance  further  down  the  Chaudiere.  Mining 
operations  were  not,  however,  commenced  until  1847,  but  partly 


a  Bailey,  Ann.  Rep.  Geol.  Surv.  Canada,  X,  N.S.,  1897,  p.  37m. 
b  Ann.  Rep.  Geol.  Surv.  Canada,  1890-1,  p.  146. 


468  NORTH   AMERICA. 

owing  to  inexperience  and  extravagance  and  partly  from  the 
irksome  seigneurial  restrictions  under  which  work  had  to  be  carried 
on,  the  earlier  workings  were  futile  and  only  desultory  attempts  to 
recover  the  placer  gold  were  made  during  the  next  16  years.  In 
1863  very  rich  gravels  wrere  found  on  the  Gilbert  river.  Four  men 
are  reported  to  have  obtained,  by  simple  panning,  72  ounces  of 
gold  in  one  day,  a  yield  equivalent  to  18  ounces  per  cubic  yard. 
A  nugget  found  at  that  time  weighed  10  ounces.  The  richer  gravels 
were  panned  and  the  poorer  treated  in  "  long-toms  "  or  short 
sluices.  One  of  the  latter  returned  12  ounces  in  one  day  and  10 
ounces  another  day.  The  news  of  these  rich  deposits  soon  spread 
and  a  considerable  number  of  men  engaged  in  the  work.  About 
that  time  it  was  officially  recorded  that  gold  to  the  value  of  £29,231 
($142,581)  had  been  obtained.  Two  large  nuggets,  one  of  52-55 
ounces  and  another  of  about  42  ounces  ($821.56  value),  wrere 
included  in  the  foregoing  return.  At  that  time  also,  alluvial  mining 
in  the  frozen  ground  was  practised  in  winter.  Alluvial  washing 
has  since  been  carried  on  intermittently.  In  1900,  and  also  in  1906, 
no  gold  was  produced.  Owing  to  the  nature  of  the  leases  under 
which  the  Chaudiere  alluvials  have  been  worked,  it  is  difficult, 
and  perhaps  now  impossible,  to  obtain  accurate  returns  of  the 
total  gold  produced.  The  Gilbert  valley  alone  is  estimated  to  have 
yielded,  between  1862  and  1894,  more  than  £200,000  ($1,000,000) 
gold.  Messrs.  Lockwood  &  Co.,  from  1868  to  1894,  obtained  from 
the  Chaudiere  3,664  ounces  gold,  while  other  parties  working  on 
Lockwood's  leases  between  1876  and  July  1st,  1880,  recovered 
gold  to  the  value  of  £88,725  ($432,806).  The  Canada  Company, 
from  July  1st,  1880,  to  June,  1887,  obtained  8,926  ounces.  The 
total  value  of  the  gold  recovered  from  the  Eastern  Townships  to 
date  has  been  estimated  at  £400,000  ($2,000,000).a 

From  the  Riviere  du  Loup,  a  right-hand  tributary  of  the 
Chaudiere,  a  considerable  quantity  of  placer  gold  has  been  taken, 
since  1852.  Of  the  attempts  made  on  a  large  scale  on  this  stream, 
some  have  been  for  a  time  successful,  but  all  works  have  eventually 
proved  unprofitable  and  have  been  abandoned.  The  pre-glacial 
gravels  in  this  region  at  times  reach  a  thickness  of  45  feet.  As  in 
the  Gilbert  valley,  the  gold  is  coarse  and  nuggetty,  averaging  865 
fine.  The  Famine  river  gravels  between  the  Gilbert  and  the  Du 
Loup  have  been  worked  for  gold,  as  also  have  those  of  Riviere 
des  Plantes,  Mill  River,  Slate  Creek,  Bras,  Pozer,  Samson,  and 
Gosselin  streams,  all  tributaries  of  the  Chaudiere. 

In  the  main  valley  of  the  Chaudiere  gold  is  found  in  appreciable 
quantity  in  few  places.     The  narrower  and  shallower  reaches,  as. 

a  Lindgren,  Trans.  Am.  Inst.  M.E.,  XXXIII,  1903,  p.  841. 


QUEBEC.  469 

near  the  Devil's  Rapids  and  the  Chaudiere  Falls,  have  given  fair 
returns,  obtained  mainly  by  "  crevicing."  On  the  main  stream 
gold  does  not  occur  below  Bisson,  a  few  miles  below  Beauce  Junction. 
Beyond  the  limits  of  the  Chaudiere  basin  other  auriferous 
localities  lie  to  the  south-west.  These  are  the  Long  Ditton  stream, 
at  the  head  of  the  St.  Francis  river,  and  within  a  few  miles  of  the 
New  Hampshire  boundary  line  ;  the  St.  Francis  river  in  the 
neighbourhood  of  Dudswell  Lake  ;  Lambton  township  on  the  south 
end  of  St.  Francis  Lake  ;  and  the  vicinity  of  Magog  and  Massawippi 
rivers,  both  left-hand  tributaries  of  the  St.  Francis.  These  deposits 
display  the  same  characters  as  those  of  the  Chaudiere. 

The  auriferous  gravels  of  the  Eastern  townships  contain  both 
pre-glacial  and  post-glacial  members.  The  former  are  much  the 
richer,  especially  when  they  lie  in  the  beds  of  the  present  streams. 
High-level  gravels  occur  and  contain  gold,  as  in  the  Gilbert  valley, 
but  in  quantities  too  minute  to  warrant  exploitation.  The  pay-dirt 
in  the  former  case  lies  immediately  on  bed-rock,  and  is  covered  by 
a  considerable  thickness  of  gravel.  Gold  is  not  evenly  distributed 
in  and  over  the  bed-rock,  but  appears  rather  to  occur  in  very  ill- 
defined  "  leads."  Owing  to  the  great  changes  in  the  climate  and 
to  the  oscillations  of  the  surface  of  the  region,  the  pre-glacial  gravels 
have  been  subjected  to  a  great  amount  of  denudation,  both  sub- 
serial  and  glacial.  In  the  valleys  and  lower  grounds  they  are  buried 
beneath  great  accumulations  of  boulder-clay  and  other  detrital 
products  of  the  ice  age.a  In  addition  they  are  often  overlain  by 
post-glacial  fluviatile  deposits,  that,  when  derived  from  auriferous 
gravels,  may,  in  rare  cases,  be  themselves  of  economic  value. 

Beneath,  and  in  the  neighbourhood  of  the  auriferous  gravels 
the  rocks  are  pre-Cambrian  (Huronian)  schists,  and  Cambrian  and 
Cambro-Silurian  slates  and  quartzites.6  In  these,  and  especially 
in  the  first-mentioned,  veins  and  veinlets  of  faintly  auriferous 
quartz  occur,  and  from  them,  the  gold  of  the  alluvials,  coarse 
though  it  be,  has  been  derived.  The  Huronian  schists  are  the 
auriferous  rocks  of  the  Ontario  region,  and  similar  Cambrian  strata 
are,  as  has  already  been  seen,  auriferous  in  Nova  Scotia.  It  is 
important  to  note  that  intrusive  diabases  occur  in  all  those  areas 
where  gold  has  been  observed  in  the  quartz  veins  of  south-eastern 
Quebec,  as  at  Leeds,  Dudswell,  Westbury,  the  Sherbrooke  anti- 
clinal, &c.c  In  1864  quartz  veins  were  worked  at  the  Devil's  Rapids 
and  the  Gilbert  river,  but  proved  unpayable. 

a  Chalmers,  Ann.  Rep.  Geol.  Surv.  Canada,  X,  1897,  p.  70j. 
b  Dresser,  Jour.  Can.  Min.  Inst.,  VIII,  1905,  p.  259. 
c  Ells,  Jour.  Can.  Min.  Inst.,  I,  1896,  p.  109. 


470 


NORTH   AMERICA. 


In  north-eastern  Quebec  gold  was  found  in  1905-6  in  a  large 
quartz  vein  on  Portage  Island,  Chibogomo  district. a  Near  Larder 
Lake  in  western  Quebec,  auriferous  areas  occur  in  the  Keewatin 
(Huronian)  schists,  east  and  north-east  of  Lake  Temiskaming, 
with  geological  features  closely  resembling  those  of  the  Lake  of  the 
Woods  and  Rainy  river  districts  of  Ontario.  So  far,  no  payable 
mines  have  been  developed.  The  gold-quartz  veins,  unlike  those  of 
the  Ontario  districts,  are  independent  of  the  schistosity.^ 

The  following  table  shows  the  official  figures  for  the  gold 
output  of  Quebec  since  1877  inclusive.0  This  gold  is  alluvial  and 
was  wholly  obtained  from  the  Eastern  Townships  placers  :  — 


1877—1880  . . 

£17,864 

1881—1890  . . 

23,424 

1891—1900  . . 

15,552 

1901  .. 

615 

1902  . . 

1,655 

1903  . . 

761 

1904  .  . 

594 

1905  . . 

Nil. 

1906  . . 

Nil. 

1907  . . 

Nil. 

Total 

£60,465 

ONTi 

iRIO. 

The  Archaean  rocks  of  Ontario,  lying  immediately  to  the 
west  and  to  the  north  of  the  Great  Lakes,  contain  numerous 
auriferous  veins,  none  of  which  have  so  far  proved  of  economic 
importance.  The  relations  of  the  various  members  of  the  Archaean 
complex  have  been  worked  out  for  the  Ontario  mining  districts  by 
A.  C.  Lawson,^  who  groups  the  rocks  under  two  great  divisions  — 
the  Huronian  and  the  Laurentian.  The  latter  is  purely  a  peno- 
logical term  and  includes  those  granites,  granite-gneisses,  and 
syenite-gneisses  apparently  younger  than  and  intrusive  into  the 
Huronian  rocks.  The  latter  are  disposed  in  great  mesh-like  bands 
and  have  been  divided  into  an  upper  (Keewatin)  and  a  lower 
(Coutchiching)  series.  The  Coutchiching  rocks  are  not  auriferous, 
and  require  no  further  mention.  The  Keewatin  greenstone- 
schists,  derived  apparently  from  basic  lavas  and  ashes,  are  essentially 
the  auriferous  rocks  of  the  province.  They  are  hornblendic,  chloritic, 
and  sericitic.e      Through  both  the  Laurentian  and  the  Huronian 

a  Obalski,  Jour.  Can.  Min.  Inst.,  IX,  1906,  p.  218. 

6  Brock,  Can.  Min.  Jour.,  Jan.,  1908. 

cAnn.  Rep.  Geol.  Surv.  Canada,  1906. 

dAnn.  Rep.  Geol.  Surv.  Can.,  Ill,  1897-8,  pp.  1-182f. 

e  Coleman,   Rep.    Bur.    Mines,    Ont.,   VI,   p.    114. 


ONTARIO.  471 

rocks  still  younger  granites  are  intrusive.  The  most  promising 
auriferous  veins  occur  at  or  near  the  contact  of  Laurentian  and 
Huronian  rocks,  but  a  few  isolated  veins  are  found  completely 
within  the  former,  and  far  more  within  the  latter.  Gold  is  also 
recorded  as  occurring  (presumably  with  pyrites)  in  felsite  dykes 
and  associated  veins  in  the  Bully  Boy  mine,  Camp  Bay.a  The 
Keewatin  schists  when  pyritous  are  themselves  auriferous.  In  the 
Western  Ontario  districts  the  matrix  of  the  gold  is  quartz.  Free- 
milling  ore  occurs  near  the  outcrops,  but  the  gold  is  generally 
associated  with  sulphides,  and  particularly  with  pyrite,  galena,  stib- 
nite,  chalcopyrite,  and  blende.  The  last-named,  contrary  to  general 
experience  elsewhere,  appears  to  denote  an  increase  in  gold  tenor. b 
The  earliest  important  find  of  gold  in  western  Ontario  was  made 
at  the  Huronian  mine,  Moss  township,  in  1871.  This  vein  is 
interesting  as  containing  fine  specimens  of  sylvanite  (telluride  of 
gold  and  silver).  It  is  associated  with  a  "  dioritic  "  rock.c  The 
Gold  Creek  mine,  Lake  of  the  Woods  district,  has  yielded  hessite 
(silver  telluride).  Its  gold  is  free-milling  and  70  to  90  per 
cent,  may  be  recovered  by  ordinary  amalgamation. 

The  auriferous  districts  of  Ontario  are  :  (a)  Rainy  River  and 
Sturgeon  Lake,  west  of  Lake  Superior  ;  (b)  the  north  shore  of  Lake 
Superior,  east  of  Nipigon  ;  (c)  Michipicoten  ;  (d)  from  Sudbury 
west  to  Ansonia  ;  (e)  Lake  Wahnapitae  ;  (/)  Parry  Sound,  Lake 
Huron  ;  (g)  Peterborough,  Hastings,  Addington,  and  Frontenac 
counties,  eastern  Ontario.  The  more  important  mines  of  western 
Ontario  are  the  Sultana,  Mikado,  Regina,  and  Black  Eagle.  The 
two  first  have  reached  depths  of  600  to  700  feet  and  have  each  pro- 
duced to  1904  more  than  £100,000  ($500,000)  gold.  The  Sultana  mine 
lies  on  the  north  shore  of  the  Lake  of  the  Woods,  seven  miles  south 
of  Rat  Portage.  It  was  first  worked  in  1882.  The  ore-bodies  may 
be  briefly  described  as  lenticular  masses  of  quartz  of  varying  size, 
interbedded  in  the  Keewatin  schists  at  or  near  the  contact  of  the 
schists  with  granitoid  gneiss.  Lenses  lying  near  the  contact  are, 
as  a  rule,  richer  than  those  further  away,  and  are  also  larger.  On 
the  adjoining  Burley  mine  a  shaft  has  been  sunk  in  the  lake  bed, 
the  depth  of  bed-rock  below  water-level  being  about  32  ieet.d  There 
are  no  well-defined  walls  limiting  the  width  of  the  schist  zone  in 
which  the  quartz  lenses  occur.  The  Sultana  ores  average  in  value 
33s.  4d.  (  $8)  per  ton.  Those  of  the  Eldorado  in  a  sheared  granite 
zone  are  somewhat  lower  in  value,  being  worth  a  little  more  than 

a  Brent,  Jour.  Can.  Mm.  Inst.,  VI,   1903,  p.  327. 
b  Merritt,  Trans.  Inst.  M.E.,  X,  1896,  p.  305. 
c  Merritt,   loc.    cit.  sup. 
d  Smith,  Jour.  Can.  Min.  Inst.,  II,  1899,  p.  87. 


472  NORTH   AMERICA. 

£1  ( $5)  per  ton.  Even  the  richer  ores  of  western  Ontario  range 
below  41s.  ($10)  per  ton. 

The  districts  of  Michipicoten,  Wahnapitae,  and  Parry  Sound 
resemble  closely  in  geological  and  mineralogical  features  the  fore- 
going districts  of  the  Rainy  River  region. 

Gold-mining  in  eastern  Ontario  dates  back  to  1865,  when  gold 
was  discovered  in  the  Marmora  district.  Since  then  no  great 
amount  of  work  has  been  done,  except  on  three  or  four  mines,  of 
which  the  two  most  important  are  the  Belmont  and  the  Deloro. 
The  country  of  these  and  other  eastern  Ontario  mines  is  dolomitic 
or  talcose  schist  with  quart  zite.  The  schists  in  the  immediate 
vicinity  of  the  veins  are  often  cut  by  basic  dykes,"  the  whole  being 
intruded  by  granite,  with  which,  according  to  Knight, h  the  ore- 
deposits  are  in  genetic  connection.  The  gangue  is  quartz  and 
dolomite,  principally  the  former,  and  the  gold  is  associated  entirely 
with  mispickel,  generally  occurring  scattered  through  the  mispickel, 
but  occasionally  in  grains  and  scales  on  the  crystal  faces  of  the 
latter.  The  arsenical  pyrites  occurs  to  such  an  extent  that  the 
veins  are  worked  rather  for  their  arsenic  than  for  the  gold.  The 
ore-bodies  are  lenticular  and  follow  the  strike  and  bedding  of  the 
talcose  schist  in  which  they  lie.  The  Belmont  mine,  from  1897  to 
1904,  recovered  16,789-79  ounces  gold  worth  £59,307  ($289,302). 
The  Deloro  mine  in  the  five  years  from  1899  to  1903  treated  35,877 
tons  ore  for  gold  worth  £37,291  ($181,907),  and  arsenic  worth 
£26,440  ($128,975),  or  a  total  value  of  36s.  Id.  ($8'66)  per  ton. 

The  recently  discovered  auriferous  deposits  of  Larder  Lake 
lie  about  34  miles  north  of  Lake  Temiskaming  and  3  J  miles  west 
of  the  Quebec  boundary  line.  They  are  essentially  irregular  quartz- 
stringers  and  veins  in  a  rusty-brown  dolomitic  limestone  belonging 
to  the  Keewatin  series  of  greenstones,  lime-silicate  rocks,  schists, 
dolomites,  cherts,  etc.  At  Abitibi  Lake,  auriferous  veins  are  found 
traversing  diabase.0 

The  only  placer  deposits  yet  known  in  Ontario  are  those  along 
the  Vermilion  and  Wahnapitae  rivers.  On  the  former  river  they 
have  a  length  of  40  miles  with  a  breadth  of  three.  They  are,  on  the 
whole,  much  too  low-grade  to  be  worked  at  present,  but  as  there  are 
many  places  where  the  average  value  is  6d.  to  7id.  (12  to  15  cents) 
per  cubic  yard,  they  may  constitute  a  dredging  asset  for  the  future. d 
The  total  gold  yield  of  Ontario  to  the  end  of   1907  is    officially 

"Wells,  Jour.  Can.  Min.  Inst.,  II,  1897,  p.  127. 

6  lb.,  VII,   1904,  p.   210. 

c  Brock,  16th  Rep.  Bur.  Mines,  Ontario,  1907,  pp.  2C7,  219. 

d  Miller,  Trans.  Amer.  Inst.  M.E.,  XXXIII,  1903,  p.  1078. 


ONTARIO. 


473 


estimated  at   £524,452   ($2,557,002).'     Returns  from    1891    are   as 
follows  :  — 


Years. 

Fine  Ounces. 

Value,  Dollars. 

Value,  Sterling. 

1891-1900 

68,453 

$1,414,988 

£290.072 

1901 

11,845 

244,837 

50,192 

1902 

11,119 

229,828 

47,115 

1903 

10,383 

188,553 

38,638 

1904 

2,285 

40,108 

8,219 

1905 

5,770 

99,157 

20,524 

1906 

3,926 

66,392 

13,605 

1907 

3,200* 

66,399 

13,606 

*  Estimated. 


BRITISH    COLUMBIA. 

Gold  was  reported  from  British  Columbia,  or  Oregon,  as  the 
Northern  Pacific  coast  was  then  termed,  as  early  as  1850.  In  that 
year  gold-quartz  veins  were  found  in  Palaeozoic  rocks  of  indeter- 
minate age,  both  on  Vancouver  and  on  Queen  Charlotte  Islands. 
These  proved  unimportant,  and  no  great  attention  was  paid  to 
the  gold  deposits  of  the  region  until  1857,  when  the  discovery  of 
rich  gravels  on  the  Fraser,  Thompson,  and  Columbia  rivers  pre- 
cipitated so  great  a  "  rush  "  from  California  that  the  value  of 
property  in  San  Francisco  was  depreciated  by  nearly  100  per  cent. 
The  rush  was  short-lived,  but  so  many  of  the  hardier  miners  were 
left  behind  that  it  became  necessary  to  form  the  district  into  a 
Crown  Colony.  In  1858,  the  first  year  of  real  production,  the  gold 
output  was  a  little  more  than  £141,000.  In  1868  the  annual  yield 
had  risen  to  more  than  £800,000,  nearly  all  of  which  was  from  the 
Fraser  river  and  its  tributaries,  and  more  especially  from  Williams 
and  Lightning  Creek,  Cariboo  district.-  This  district,  after  half  a 
century  of  work,  still  remains  the  most  important  placer  region  in 
British  Columbia.  In  1872  the  rich  deposits  of  the  Cassiar  district, 
at  the  head-waters  of  the  Dease  river,  were  discovered.  They  have 
since  yielded  more  than  a  million  pounds  sterling  in  alluvial  gold. 
With  the  rush  to  Granite  Creek,  Similkameen,  there  occurred 
the  last  of  the  notable  placer  discoveries  of  British  Columbia.  Few 
of  these  placer  deposits  now  offer  huge  fortunes  or  even  indeed  a 
mere  livelihood  to  individual  miners  unassisted  by  machinery.  All 
are  being  worked  by  companies  possessing  sufficient  capital  for  the 
purchase  and  erection  of  expensive  hydraulic  plant,  steam  shovels, 
or  dredges.  In  most  cases  water  to  command  the  gravels  is 
brought  from  great  distances,  often  as  great  as  30  miles. 


474 


NORTH    AMERICA. 


The  auriferous  streams  of  the  Cariboo  district  lie  for  the  most 
part  within  a  radius  of  20  miles  from  Barkerville.  The  area  forms 
a  portion  of  the  watershed  of  the  Fraser,  being  drained  by  its 
tributaries,  the  Quesnelle,  Cottonwood,  and  Willow  rivers.  The 
alluvials  have  been  in  the  past  exceedingly  rich,  quite  as  much  so 
as  the  better-known  gravels  of  the  Yjikon.  Williams  Creek,  Cariboo 
district,  is  reported  to  have  yielded  upwards  of  £5,000,000  from 
a  length  of  2|  miles  of  stream  bed.ra  Lightning  Creek  has  been 
quite  as  rich.  The  bed-rocks  of  the  region  are  the  crystalline  Cariboo 
schists  of  Lower  Palaeozoic  age.6  The  schists  contain  low-grade 
pyritous  gold-quartz  veins  with  a  little  galena.  The  sulphides 
themselves  occasionally  carry  high  values  in  gold,  but  in  no  vein 
yet  discovered  has  gold  been  found  comparable  in  size  with  the  coarse 
nuggets  of  the  gravels.  In  one  vein  alone,  viz.,  Perkins  Ledge  on 
Burns  Mount,  has  free-milling  gold-quartz  been  seen.  The  Cariboo 
schists,  especially  along  vein  fissures,  are  often  graphitic. 


V 

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Fig.  154.    Section  through  Lightning  Creek,  Cariboo  (Atkin). 

Much  of  the  gold  of  Cariboo  has  been  derived  from  "  benches," 
as  the  remnants  of  ancient  river  terraces  left  high  up  on  the  valley 
sides  are  termed.  The  present  drainage  system  differs  considerably 
from  that  of  pre-glacial  times.  The  older  gravels  and  those  of  the 
valley  bottoms  are  pre-glacial  and  upper  Tertiary.  The  gold  of 
the  richer  streams — Williams,  Lightning,  Lowhee,  Grouse,  &c. — 
is  exceedingly  coarse.  At  places  on  Lightning  Creek  no  gold  particles 
weighing  less  than  10  grains  were  found.  The  largest  nugget  from 
Cariboo  was  taken  from  Butcher  Bench  on  Lightning  Creek  and 

"  Brewer,  Mines  and  Minerals,  July,  1904. 

6  Atkin,  Q.J.G.S.,  LX,  1904,    p.  389;   Id.,  Geol.  Mag.,  II,  1905,   p.  104;    Id.,  loc. 
cit.,  Ill,  1906,  p.  514. 


Plate  XXV. 


Williams  Creek,  Cariboo. 


Hydraulic  Sluicing,  Cunningham  Creek,  Cariboo. 


BRITISH    COLUMBIA.  475 

weighed  about  40  ounces.  The  gold  nuggets  in  the  rich  shallow 
creek-deposits  vary  greatly  in  appearance  in  different  creeks,  and 
even  in  different  parts  of  the  same  stream.  Nuggets  from  the  higher 
reaches  are  generally  large  and  angular,  but  become  smaller  and 
smoother  as  they  descend  the  streams.  The  alluvial  gold  is  sup- 
posed by  Atkin  to  have  been  derived  from  pre-glacial  surface 
secondary  enrichments  at  vein  outcrops.  Quartz  boulders  con- 
taining both  gold  and  pyrite  have  been  found  in  the  wash. 

The  Cariboo  gravels  are  now  wholly  worked  by  large  companies, 
the  Cariboo  Gold  Mining  Company  (formerly  Cariboo  Consolidated 
Company)  probably  operating  on  a  larger  scale  than  any  other 
alluvial  mine  in  the  world.  Its  fluming  and  races  are  more  than 
33  miles  long  and  deliver  5,000  miner's  inches  (7,500  cubic  feet 
per  minute)  of  water  under  a  head  of  400  feet.  The  gravels  treated 
vary  in  value  from  lOd.  to  3s.  lOd.  per  cubic  yard.  This  company 
from  June  1st,  1894,  to  June  22nd,  1904,  recovered  gold  to  the 
value  of  £252,957  ($1,233,936).  The  new  company  is  increasing 
the  water  supply,  as  lack  of  water  has  always  been  a  drawback 
on  this  as  on  other  British  Columbian  placer  fields.  The  deposits 
still  to  be  treated  vary  in  depth  from  400  to  600  feet,  and  it  is 
estimated  that  there  are  yet  available  500,000,000  cubic  yards  of 
gravel.  The  value  of  the  pay -gravel  treated  on  Lightning  Creek  in 
1905  and  1906  appeared  to  vary  between  9s.  3d.  ( $2.22)  and  16s.  6d. 
($3.96)  per  cubic  yard,  but  notwithstanding  these  high  values, 
and  the  generally  high  tenor  of  the  average  gravel  treated  (5  to  6 
grains  per  cubic  yard),  none  of  the  larger  companies  have  paid 
dividends.  A  considerable  portion  of  the  gravel  is  cemented  and 
requires  crushing  before  treatment. 

In  recent  years  several  attempts  have  been  made  to  recover 
the  gold  of  the  "  bars  "  of  the  Fraser  river  by  dredging.  ;'  Dipper," 
clam-shell,  and  suction  dredges  have  all  been  tried  and  have  all 
failed.  Only  moderate  success  has  as  yet  been  attained  with  bucket 
dredges,  their  breakdown  being  attributable  in  most  cases  to  faulty 
design.  High  water  in  the  Fraser  river  occurs  in  June,  low  water  in 
March.  The  current  is  swift  and  in  flood  time  may  attain  15  knots 
per  hour.  The  breaking  away  of  ice  barriers  constitutes  a  serious 
menace  to  dredges.  Very  little  silt  is  found  in  the  river  bed,  which 
is  tightly  packed  with  boulders.  Strong  machinery  is  therefore 
required  to  break  through  to  the  gravel  beneath.  Since  the  stream 
is  very  deep,  dredging  is  practicable  only  on  the  beaches  and 
"  bars."  Behind  the  latter,  dredging  may  be  carried  on  nearly  all  the 
year  round.  The  general  tenor  of  the  gravel  to  be  dredged  is 
estimated  at   5  grains  gold  per  cubic  yard.a 

a  Stringer,  Mm.  Jour.,  March  16,  1907- 


476  NORTH     AMERICA. 

The  Atlin  division  of  the  Cassiar  district  is  in  the  extreme 
north  of  British  Columbia,  and  its  auriferous  streams  flow  into 
Atlin  Lake  from  the  east.  The  earliest  recorded  discovery  was 
made  on  Pine  Creek  early  in  1898  by  McLaren  and  Miller.  Old 
and  rotted  sluice  boxes  have  been  found  in  the  neighbourhood, 
and  it  is  commonly  believed  that  the  deposits  were  known  prior  to 
that  year.  The  bed-rocks  of  the  gold-bearing  gravels  are  the  "  Gold 
Series  "  of  Gwillim.a  They  are  Palaeozoic  slates,  actinolite-  and 
biotite-schists,  and  magnesian  rocks  (dunite,  peridotite,  magnesite, 
serpentine),  together  with  younger  greenstones  (andesitic).  In 
Pine  Creek  valley  are  numerous  diabasic  dykes  and  some  small 
areas  of  diorite  which  may  be  related  to  the  greenstone.  The 
schists  occur  only  near  the  granite  contact.  Well-defined  pyritous 
quartz  veins  cross  the  slates  of  the  Gold  Series.  While  their  tenor 
in  gold  is  low,  it  is  probably  from  them  and  from  the  auriferous 
pyrites  of  the  biotite-slates  that  the  gold  of  the  streams  has  been 
derived.  An  interesting  occurrence  of  gold  in  the  pyritous  biotite- 
slates  is  reported  from  Wright  Creek,  falling  into  Surprise  Lake. 
Here  the  stream  flows  over  heavily  mineralised  slates  and  gold  is 
found  deep  down  within  the  bed-rock.  It  is  not  clear,  however, 
whether  the  gold  is  alluvial  and  has  sunk  into  crevices,  or  whether 
it  is  derived  from  the  decomposition  of  the  pyrites. b  The  latter  is, 
however,  probably  the  case.  A  similar  area  of  auriferous  pyritous- 
rock  crosses  Pine  Creek,  near  Willow.  Gwillimc  concludes  that  the 
placer  gold  is  derived  from  the  country  rather  than  from  the  veins. 
The  auriferous  alluvial  belt  lies  to  the  east  of  Atlin  Lake,  and 
covers  an  area  of  150  square  miles.  The  gravels  are  pre-glacial, 
glacial,  and  post-glacial.  The  first  are  the  richest,  though  local 
concentrations  may  occur  in  the  last. 

The  old  gravels  of  Atlin  are  in  a  state  of  advanced  decomposition, 
appearing  as  shining  pebbles  in  a  paste  of  yellowish  mud.  Most 
of  the  gold  lies  on  bed-rock  or  within  8  feet  above  it.  The  grains 
are  for  the  most  part  coarse,  and  of  the  size  and  shape  of  flax  seed. 
The  largest  nuggets  yet  found  have  been  83  ounces  (with  some 
quartz),  36i  ounces,  and  28|  ounces  respectively.  The  principal 
creeks  now  being  worked  are  Pine,  Spruce,  Willow,  Birch,  Boulder, 
and  McKee.  Steam  shovels  are  used  to  handle  the  gravels.  That 
on  Pine  Creek,  with  If  yard  dipper,  is  capable  of  moving  3,000 
cubic  yards  in  24  hours.  Working  night  and  day  from  August  15th 
to  October  25th,  1906  (71  days),  with  36  men,  this  plant  recovered 
more  than  £5,000  ( $25,000)  gold.  Steam  shovels  are  also  employed 
on  Spruce  Creek,  the  principal  tributary  of  Pine  Creek.    On  McKee 

?  Ann.  Rep.  Geol.  Surv.  Canada,  XII,  1899,  p.  16b. 

"  Loc.  cit.,  p.  43b. 

cJour.   Can.   Min.   Inst.,  V,   1902,  p.   30. 


BRITISH     COLUMBIA.  477 

Creek  the  bed-rock  surface,  also  to  be  worked  by  steam  shovel 
(5  cubic  yards  dipper),  varies  in  value  from  12s.  6d.  ($3)  to  50s. 
($12)  per  square  yard,  an  average  being  perhaps  18s.  9d.  ($4-50). 
All  the  gravel,  whether  moved  by  steam-shovel,  or  otherwise,  is 
sluiced.  Two  dredges  have  been  erected,  but  both  have  failed 
completely  owing  to  adverse  local  conditions. 

Other  mining  divisions  of  British  Columbia  of  less  importance, 
in  which  placer  gold  is  being  recovered,  are  the  Liard,  Stikine, 
and  Skeena,  south  and  south-west  of  Atlin,  and  with  geological 
conditions  similar  to  those  of  Atlin  ;  the  Lilloet  division,  along 
the  benches  of  the  Fraser  river  and  in  Bridge  river  and  Cayuse 
Creek  ;  and  the  Fort  Steele  division  of  East  Kootenay.  In  the 
last-named  the  first  alluvial  discoveries  were  on  Wild  Horse  Creek, 
joining  the  Kootenay  at  Fort  Steele.  This  stream  is  reported  to 
have  yielded  for  two  years  1  to  1 J  ounces  of  gold  per  man  per  day. 
It  was  worked  out  by  the  end  of  1866.  The  yield  of  placer  gold  in 
British  Columbia  for  1907  was  £169,740  ($828,000),  while  the  total 
value  of  the  placer  yield  from  1852  to  1907  inclusive  has  been 
£14,257,566  ($69,549,103). 

The  important  gold  lodes  of  the  province  are  all  situated  in 
the  south  and  the  south-east,  generally  only  a  few  miles  north  of 
the  international  boundary.  Of  these,  the  best  known  are  those  of 
Rossland,  five  miles  north  of  the  boundary,  in  the  West  Kootenay 
district.  The  town  and  mines  are  on  Red  Mountain  at  the  head 
of  Trail  Creek,  and  are  at  an  average  altitude  of  3,140  feet  above 
sea-level.  The  lodes  were  found  in  the  summer  of  1890,  all  the 
principal  mines  of  the  present  time  being  staked  on  the  same  day. 
One,  and  as  it  eventually  proved,  the  richest,  was  given  away  for 
the  price  of  the  recording  fees  ($12.50).  The  field  suffered  for 
several  years  from  lack  of  transport  facilities,  but  in  1896  it  was 
connected  by  railway  with  the  outside  world.  Mining  and  milling 
costs  have  of  late  years  been  considerably  reduced  by  the  construc- 
tion of  another  railway,  giving  cheap  fuel,  and  by  the  introduction 
of  electric  power.  From  1894  to  1905  inclusive  2,212,271  tons 
(long)  have  been  smelted  for  a  yield  of  £6,837,065  ($33,351,536) 
or  £3-625  ( $17.68)  per  ton.  Of  this  value  a  considerable  proportion 
is  derived  from  the  copper  and  silver  content  of  the  ore.  The  fol- 
lowing table a  of  typical  assays  shows  the  average  proportion 
in   metals  of  the  ore  now  being  treated  : — 


Gold. 

Silver. 

Copper. 

Ounces  per  ton. 

Ounces  per  ton. 

Per  cent. 

•441 

•5 

1-15 

•  5 

•  3 

•  9 

•  4 

•  54 

•7 

1-18 

2-318 

3-62 

a  Brock,  Rep.  Geol.  Surv.  Canada,  No.  939,  1906,  p.  18. 


478  NORTH     AMERICA. 

The  basement  rocks  of  the  Rossland  area  are  Lower  Carboni- 
ferous sedimentaries  (clays,  limestones,  and  quartzites)  inter- 
stratified  with  tuffs  and  lava  flows.  Through  these  have  been 
intruded  a  succession  of  igneous  rocks.  The  oldest  were  augite- 
porphyrite  agglomerates  and  lavas.  They  were  followed  by 
monzonite,  which  in  its  turn  was  intruded  by  apophyses  of 
granodiorite.  The  intrusions  range  in  age  from  Upper  Mesozoic 
to  Lower  Tertiary.  The  eruptions  were  continued  through  the 
Tertiary  period,  furnishing  andesites  at  the  surface  and,  at  depth 
in  the  mines,  mica-lamprophyre  dykes  of  differing  and  uncertain 
age.  Some,  indeed,  cut  and  fault  the  ore-bodies.  The  whole  area 
has  been  subjected  to  comparatively  recent  glaciation. 

The  Rossland  ore-bodies  may  occur  in  any  of  the  country 
rocks,  with  the  exception  of  the  later  dykes.  Augite-porphyrite 
and  the  coarser  grey  granitoid  rocks  (monzonite)  are  the  most 
favourable.  All  the  proven  productive  zones  are  situated  near  or 
between  exposures  of  alkali-syenite  (alaskite).  The  remainder 
of  the  stratified  rock  is  mineralised,  but  too  diffusely  to  be  of 
economic  importance.  The  ore  deposits  occur  in  fissure  veins 
formed  by  fracture,  or  by  fracture  and  replacement,  and  also  in 
zones  of  Assuring  and  shearing,  in  which  the  ore  is  found  in  a  close 
network  of  veinlets.  The  two  foregoing  have  furnished  the  more 
important  ore-bodies,  but  irregular  impregnations  in  the  country 
are  also  met  with  and  are  worked.  The  gangue  is  mainly  country, 
with  occasional  quartz  and  calcite.     The  ores  occur  :  — 

(a)  As  massive  pyrrhotite  and  chalcopyrite  with  pyrite  and 
arsenopyrite.  Free  gold,  though  rarely  visible,  occurs 
in  this  matrix,  as  also  does  galena  and  blende.  Small 
quantities  of  nickel  (-65  per  cent.)  and  cobalt  ('59 
per  cent.)  are  at  times  recognised. 

(6)  As  massive  pyrrhotite  with  very  little  copper  and  gold. 

(c)  As  pyrite,  marcasite,  and  arsenopyrite  veins  with  occasional 

argentiferous  galena  and  blende. 

(d)  As    impregnations    of    arsenopyrite,     pyrrhotite,     pyrite, 

molybdenite,  chalcopyrite,  bismuthinite,  and  native 
gold,  especially  in  the  neighbourhood  of  pegmatitic  or 
aplitic  alkali-syenite  dykes  (Grant,  Jumbo). 

(e)  As  gold-bearing  quartz  veins   (O.K.   and  I.X.L.). 

In  typical  ores  the  highest  value  is  in  gold,  followed  by  copper, 
and  then  by  silver.  The  proportion  of  free  gold  does  not  appear 
to  diminish  in  depth,  nor  does  the  gold  accompany  any  specified 


BRITISH     COLUMBIA.  479 

mineral,  though  in  some  places  an  increase  in  the  amount  of  chalco- 
pyrite  denotes  an  increase  in  gold  tenor.  The  chief  lodes  of 
Rossland  are  the  Le  Roi — Centre  Star,  Main,  South,  and  Josie. 
Sharply  denned  walls  are  lacking,  and  the  width  of  a  lode  is  deter- 
mined often  only  by  economic  considerations.  Within  the  lodes, 
shoots  or  pay-streaks,  often  lenticular  and  of  great  size,  furnish 
much  of  the  ore,  and  are  most  common  when  the  lode  is  intersected 
by  faults  and  dykes. 

The  ore  deposits  were  formed  by  aqueous,  mineral-laden 
solutions  of  high  temperature.  According  to  Brock,  no  secondary 
sulphide  enrichment  of  importance  has  taken  place.  This  view  is 
not,  however,  supported  by  MacDonald,a  who  regards  the  shoots 
as  zones  of  secondary  enrichment.  The  total  costs  of  the  mining 
and  smelting  of  Rossland  ores  lies  between  31s.  6d.  ($7.56)  and  41s. 
8d.  ($10.00)  per  ton.  To  the  end  of  1903  the  Rossland  mines  had 
paid  £487,285  ($2,377,500)  in  dividends. 

The  Boundary  district  lies  to  the  west  of  Rossland,  and  derives 
its  name  from  its  proximity  to  the  international  frontier.  Its  wealth 
lies  in  its  large  low-grade  copper  sulphide  deposits,  rather  than  in 
gold,  but  gold-quartz  veins  of  no  great  size  are  found  in  the  neigh- 
bourhood of  the  copper  lodes.  The  country  is  limestone,  horn- 
blende-schist, and  tuff,  the  two  last  being  calcareous.  All  are 
intruded  by  alkali-syenite  (pulaskite)  dykes.  The  sulphide  lodes 
are  usually  confined  within  well-defined  walls  and  contain  chalco- 
pyrite,  pyrite,  arsenopyrite,  galena,  and  blende.  Tetrahedrite 
and  rich  silver-sulphides  also  occur. b  There  is  a  complete  absence 
of  oxidation  at  the  outcrop  of  these  lodes — a  general  characteristic  of 
British  Columbia  ore,  and  largely  due  to  the  recent  glacial  erosion  of 
the  surface.  About  one-third  only  of  the  value  of  the  product 
of  the  Boundary  mines  is  derived  from  gold.  The  annual  output 
of  the  district  is  large,  and  has  steadily,  grown  from  390,000  tons 
in  1901  to  1,160,000  tons  in  1906.  The  ores  are  entirely  self-fluxing 
and  require  neither  double  smelting  nor  addition  of  foreign  fluxes 
or  metals.  The  principal  mines  are  the  Granby,  the  British  Columbia 
Copper  Company,  and  the  Dominion  Copper  Company.  The  first- 
named  furnishes  the  great  bulk  of  the  ore  sent  to  the  smelters  from 
the  Boundary  district,  and  is  indeed  the  largest,  in  point  of  tonnage 
treated,  of  metal  mines  within  the  Dominion.  It  rivals  the  famous 
Ducktown  (Tennessee)  copper  mines  in  this  respect,  and  also  in 
lowness  of  costs.     Its  ores  contain  from  5s.  to  6s.  worth  of   gold 

a  Eng.  Mm.  Jour.,  Aug.  8,  1903. 

6  Brock,  Ann.  Rep.  Geol.  Surv.  Canada,  XV,  1902,  p.  92a. 


ISO 


NORTH     AMERICA. 


and  silver  and  27  to  30  pounds  copper  per  ton.      Returns  from 
the  Granby  mines  for  the  last  two  years  available  are :  — a 


1905. 

L906. 

Tons  smelted 

590,120 

832,346 

Copper  sold  (lbs.).  . 

14,237,622 

19,939,004 

Gold,  fine  ounces 

42,884 

50,020 

Silver,  fine  ounces 

212,180 

316,947 

Net  profit  per  ton 

6s.  8d. 

10s.  Id. 

In  November,  1907,  the  mine  was  closed  down  for  some 
months  owing  to  the  then  low  price  of  copper  (£63  per  ton). 

Other  vein-gold  districts  in  British  Columbia  are  Nelson 
(including  the  Ymir  and  Athabasca  mines),  Coast  (with  Vancouver 
Island)  and  Revelstoke.  These  present  no  characteristics  warranting 
special  mention.  The  output  of  vein  gold  for  the  province  during 
1907  was  £831,316  ($4,055,200),  of  which  95  per  cent,  was  a  smelter 
product,  only  two  stamp  batteries  (at  Ymir,  Nelson,  and  at  Yale) 
being  in  operation.  The  total  yield  of  vein  gold  in  British  Columbia 
to  the  end  of  1907  has  been  £9,239,534  ($45,070,897). 

The  producing  gold  districts  of  British  Columbia  in  1906  were 
the  following  : — & 


District. 

Division. 

Value  of 

Alluvial 

Gold. 

Value  of 
Vein  Gold. 

Total 
Value. 

Cariboo 

Cariboo 

£72,939 

£72,939 

Quesnel 

8,118 

.... 

8,118 

Oniineca 

2,050 

.... 

2,050 

Cassiar 

Atlin          

93,275 

.... 

93,275 

Liard,  Stikine,  Skeena  . . 

9,020 

£8 

9,028 

East  Kootenay 

.Fort  Steele" 

2,132 

.... 

2,132 

Windermere  Golden 

■  •  •  . 

42 

42 

West  Kootenay 

Nelson 

205 

49,480 

49,685 

Ainsworth. . 

.... 

80 

80 

Slocan 

.... 

292 

292 

Trail  Creek 

.... 

446,431 

446,431 

Revelstoke,  Trout  Lake 

and  Larder 

820 

8,678 

9,498 

Lilloet 

Lilloet 

3,444 

720 

4,164 

Yale 

Boundary 
Similkameen,  Nicola,  and 

676 

398,842 

399,518 

Vernon 

512 

25 

537 

Yale,       Ashcroft,       and 

Kamloops 

1,025 

911 

1,936 

Coast 

Nanaimo,  Alberni,  Clayo- 
quot,  Quatsino,   New 
Westminster,      and 

Victoria 

205 

43,772 

43,977 

£194,421 

£949,281 

£1,143,702 

"  Rickard,  Forbes,  Min.  Sci.  Press,  April  20,  1907. 
b  Ann.  Rep.  Bur.  Mines,  British  Columbia,  1906. 


481 


YUKON. 


Gold  has  been  known  from  the  Yukon  river  since  1869.  The 
alluvial  deposits  earliest  worked  in  this  region  were  far  up  the 
Yukon  on  the  Big  Salmon,  Lewes,  Pelly,  and  Stewart  rivers,  about 
200  miles  north  and  north-east  of  Atlin  Lake.  The  first-named 
was  actively  worked  in  1881  ;   the  last,  and  up  to  then  the  richest, 


Fig.  155.     Sketch  Map  showing  Geology  in  the  Vicinity  of  Klondike  (McDonnell). 

Older  Rocks  :  Na.  Nasina  series.     M.  Moosehide  group.     K .  Klondike  series. 

Younger  Rocks  :  G.  Granite.     Sp.  Serpentine.     D.  Diabase.     L.  Lower  Tertiary  (Kenai  series). 

from  1885  to  1886.  In  the  latter  year  the  placers  of  the  Forty  mile 
region,  the  greater  part  of  which  afterwards  proved  to  be  in  Alaskan 
territory,  were  discovered,  and  soon  after,  those  of  the  Sixtymile 
river,  the  last  being  entirely  within  Canadian  jurisdiction.  This  last 
stream  furnished  most  of  the  gold  of  the  Yukon  until  1897,  when  the 

Gl 


482  NORTH     AMERICA. 

surpassing  richness  of  the  streams  in  the  neighbourhood  of  the 
Klondike  river  became  generally  known,  and  set  in  motion  the  most 
extraordinary  rush  of  recent  years — one  that,  as  usual,  meant 
fortunes  for  the  few  and  desperate  privation  for  the  many.  Nothing 
like  it  had  happened  since  the  great  Australian  rushes  of  the 
'fifties.  Its  occurrence  is,  however,  of  too  recent  date  to  warrant 
a  description  in  this  place. 

The  Klondike  goldfields  lie  immediately  to  the  south  of  the 
64th  parallel  of  north  latitude,  and  50  miles  east  of  the 
international  boundary.  The  auriferous  area  is  about  800 
square  miles  in  extent.  It  lies  between  the  Klondike  river 
on  the  north  and  the  Indian  river  on  the  south  and  is 
bounded  on  the  west  by  the  Yukon  itself,  and  largely  on  the 
east  by  Dominion  Creek,  a  tributary  of  Indian  river.  It  is  thus 
an  almost  complete  physiographic  unit.  Its  maximum  elevation 
is  the  Dome,  4,250  feet  above  sea-level,  and  3,060  feet  above  Dawson, 
the  chief  town  of  the  Yukon,  situated  on  that  river  at  the  mouth  of 
the  Klondike  tributary.  All  the  streams  in  this  area  are  auriferous, 
but  only  a  few  are  sufficiently  rich  to  warrant  exploitation  under 
existing  circumstances.  The  existence  of  gold  in  the  region 
appears  to  have  been  known  in  1894,  but  the  extraordinary 
richness  of  some  of  the  valleys  was  not  suspected  until  two  years 
later,  when  Carmack,  returning  from  visiting  a  brother  prospector 
on  Goldbottom  Creek,  made  his  famous  discovery  on  Bonanza  Creek. 

The  oldest  and  most  important  rocks  in  the  district  are 
metamorphic  schists,  partly  of  sedimentary  and  partly  of  igneous 
origin.  Their  age  Is  uncertain  and  they  are  possibly  Cambrian  or 
pre-Cambrian.a  They  have  been  divided  by  McConnell&  into  the 
Nasina  and  Klondike  series,  and  with  them  is  grouped  the  Moose- 
hide  diabase,  exposed  only  in  the  immediate  neighbourhood  of 
Dawson.  The  Nasina  series  are  ancient  sedimentary  rocks — sands 
and  sandy  clays — now  altered  to  quartzites  and  quartz-mica- 
schists,  associated  in  places  with  bands  of  green  chlorite-  and 
actinolite-schist,  the  latter  probably  representing  original,  more 
or  less  basic  igneous  intrusions.  The  rocks  of  the  Nasina  series 
occur  both  to  the  south  and  to  the  north  of  the  main  auriferous 
area,  and  are  probably  the  oldest  in  the  district.  The  Klondike 
series  of  originally  widely-differing  igneous  rocks — quartz-porphyries, 
granite-porphyries,  and  basic  porphyritic  rocks0 — now  converted 
into  light-coloured  sericite-  and  green  chlorite-schists,  are  important 
as  being  the  country  of  the  gold  veins  from  whence  the  alluvial 

a  Tyrrell,  Econ.  Geol.,  II,  1907,  p.  345. 

6  Ann.  Rep.  Geol.  Surv.  Canada,  XIV,  1901,  p.  12b. 

c  Barlow,  lb.,  p.  19b. 


YUKON.  483 

gold  has  been  derived.  They  occupy  the  greater  portion  of  the 
auriferous  area  outlined  above,  lying  across  it  as  a  north-west  to 
south-east  belt  with  an  average  width  of  some  16  miles.  South-east 
of  the  Dome  the  belt  is  bounded  on  the  north  by  Flat  Creek,  and 
on  the  south  by  Indian  river.  The  series  is  intruded  by  numerous 
dykes  and  stocks  of  quartz-porphyry,  rhyolite,  and  andesite,  so 
much  younger  that  they  are  still  unaltered  by  dynamo-metamor- 
phism.  Schists  similar  to  these  occur  in  other  auriferous  districts 
in  the  Yukon  province,  as  in  the  Fortymile  district,  on  Henderson 
Creek,  and  in  the  Stewart  Valley.  Their  general  age  is  believed  by 
McConnell  to  be  that  of  the  Pelly  gneisses  (Archaean),  and  the 
sericite-schists  of  the  Klondike  themselves  indeed  show  a  gradual 
transition  to  augen-gneisses  along  a  section  from  Eldorado  Creek 
to  Indian  river.  The  relation  of  the  Moosehide  diabase  to  the  rocks  of 
the  Klondike  series  is  uncertain,  but  as  the  diabase  seems  to  have 
undergone  less  metamorphism  than  the  latter,  it  may  merely 
represent  a  later  manifestation  of  the  same  volcanic  activity. 

Unaltered  Tertiary  sediments  of  no  great  importance  occur 
in  the  area.  The  more  recent  massive  and  intrusive  igneous  rocks 
are  granites  ;  andesite  dykes,  stocks,  and  remnants  of  flows  ; 
diabase  stocks  and  dykes  ;  and  quartz-porphyries  shading  into 
rhyolites.  The  foregoing  is  the  apparent  order  of  succession,  the 
granite  being  the  oldest  rock.  The  andesites  are  of  Lower  Tertiary 
age,  and  on  the  left  bank  of  the  Yukon  are  traversed  by  a  broad 
diabase  dyke.  Most  of  the  foregoing  are  seen  intrusive  through 
the  schists. 

The  auriferous  gravels  of  the  Klondike  may  be  classified  in 

-descending  order  in  general  altitude  as  follows  : — 

I        . .  .  .  . .      Klondike  River  Gravels. 

(a)    High-level  Gravels  . .  J 

I  "  White  Channel  "       f  Yellow  Gravels. 
Gravels  \  White  Gravels. 

(&)    Gravels  at  inter- 
mediate levels  . .        . .  . .    •     . .         Terrace  Gravels. 

iGulch  Gravels, 
(c)     Low-level  Gravels  . .  . .  . .  -I  Creek  Gravels. 

(River  Gravels. 

The  high-level  gravels  lie  at  elevations  of  1 50  to  300  feet  above 
the  present  valley  bottoms  and  are  the  remnants  of  a  Pliocene 
valley  gravel  deposited  before  the  whole  country  received  the 
comparatively  recent  uplift  (500  to  700  feet)  that  by  increasing 
the  grade  of  its  streams  enabled  them  to  deepen  their  valleys. 
These  high-level  gravels  may  be  separated  into  ancient  local  creek 
gravels  and  the  ancient  river  gravels  of  the  Klondike  stream.  The 
latter  overlie  the  former  and  have  a  thickness  of  150  to  175  feet, 
but,  since  their  material  has  been  brought  from  outside  the  auriferous 


484  NORTH     AMERICA. 

area,  are  of  little  economic  importance.  The  high-level  creek  gravels, 
on  the  other  hand,  have  a  considerable  value,  and  have  furnished 
much  of  the  Klondike  gold.  They  are  subdivided  into  upper  and 
lower  members,  the  former  being  rusty  yellow  gravels  restricted 
in  area,  the  latter,  white  and  more  widely  distributed.  The  white 
gravels  are  composed  of  rounded  quartz  pebbles,  with  rounded, 
sub-angular,  or  wedge-shaped  boulders  of  quartz,  often  2  or  3  feet 
in  diameter,  all  packed  in  a  matrix  of  angular  grains  of  quartz 
and  sericite.  Pebbles  of  sericite-schist  are  common.  These  gravels 
are  locally  known  as  "  white  channel  "  gravels.  No  fossil  remains 
have  been  found  in  them.  They  vary  in  thickness  from  a  few  feet 
to  150  feet,  and  in  width  from  100  feet  to  |-mile  or  more.  The 
"  white  channel  "  gravels  have,  as  has  been  stated,  furnished  much 
of  the  gold  of  the  Klondike,  not  only  to  direct  mining,  but  also  by 
degradation  to  the  lower-lying  valley  deposits.  Their  course  in  the 
richer  valleys  is  easily  traced  by  the  horizontal  white  band  of 
tailings  sweeping  round  the  hill  slopes.  They  are  regarded  as 
stream  deposits  by  McConnell.  In  character  they  certainly 
resemble  closely  the  auriferous  river  gravels  now  being  deposited 
in  New  Zealand  by  the  snow-fed  rivers,  Clutha  and  Kawarau.  These 
streams  have  remarkably  even  gradient  and  a  fairly  swift  current, 
while  their  debris  is  derived  from  the  degradation  of  a  somewhat 
easily  disintegrated  mica-schist  area. 

The  terrace  gravels  lying  on  the  valley  slopes  below  the  "  white 
channel  "  are  also  remnants  of  former  valley  bottoms  through  which 
the  streams  have  cut  during  a  rapid  deepening  of  their  beds.  They 
are  irregular  in  extent,  seldom  exceeding  a  few  yards  in  width 
and  a  few  hundred  yards  in  length.  They  occur  at  various  altitudes 
and  may  be  considered  to  mark  periods  of  temporary  cessation 
of  uplift. 

The  low-level  gravels  occupy  the  bottom  of  the  existing  valleys. 
Their  material,  together  with  their  gold,  has  been  derived  from 
the  decomposed  schists  on  the  valley  slopes,  from  the  high-level 
gravels,  and  from  the  terrace  gravels.  They  lie  on  decomposed 
schist  bed-rock,  and  are  covered  by  black  frozen  "muck"  (silt, 
vegetable  matter,  and  ice,  the  last  often  forming  75  per  cent,  of  the 
mass)  of  a  thickness  of  2  to  30  feet.  The  Gulch  gravels  occupy  the 
upper  portions  of  the  main  creek  valleys  and  of  the  small  tributary 
valleys.  Owing,  of  course,  to  the  shorter  distance  they  have 
travelled,  their  boulders  and  pebbles  are  larger  and  more  angular 
than  those  of  the  creek  gravels.  The  only  river  gravels  yet  proven 
to  contain  gold  in  remunerative  quantities  are  those  bordering 
the  Klondike  river  below  the  mouth  of  Hunker  Valley. 

The  principal  auriferous  streams  all  flow  from  and  over  the 
sericite-schists  of  the  Klondike  series.     The  richest  is  undoubtedlv 


YUKON. 


485 


Bonanza  Creek,  with  its  main  tributary,  Eldorado  Creek,  Along 
these  two  streams  the  valley  bottom  gravels  are  the  most  productive. 
These  are  followed  in  economic  importance  by  the  white  channel 
gravels,  and  then  at  a  long  interval  by  the  terrace  gravels.  Some 
of  the  earlier  claims  (which  were  limited  in  length  of  channel  to 
500  feet)  were  exceedingly  rich.  A  claim  on  Bonanza  Creek  only 
80  feet  in  length  yielded  over  £60,000  ($300,000)  gold,  another 
(No.  17)  of  full  length,  on  Eldorado  Creek,  had  yielded  up  to  the 
end  of  1902  no  less  than  £300,000  ($1,500,000).  The  Eldorado  has, 
indeed,  proved  the  richest  creek  in  the  Klondike  district,  and  is 


«.  Mack, 
b.  Stream  gravels. 
C.   Terrace  gravels, 
d.    White  gravels.} 


Scale.— 400  tVet  to  I  inch. 


orartl 


a.  Muck. 

b.  Stream  firax'rls. 

c.  Terrace  gravels. 

d.  While  Channel  gravels, 
r  High  level  river  gravels. 
f.    Klondike  schists. 


Figs.  156  and  157.    Ideal,  sections  across  "Bonanza  Valley  (McConntll). 


possibly  the  richest  ever  discovered.  To  1902  a  total  value  of 
£5,000,000  ( $25,000,000)  had  been  recovered  from  it,  and  more  has 
since  been  obtained.  It  is  estimated  that  only  5  per  cent,  of  the 
total  bulk  (250,000,000  cubic  yards)  of  the  gravels  on  Bonanza  Creek 
has  been  or  may  be  worked  by  drifting,  the  remainder  being  left 
to  be  treated  by  hydraulic  methods  or  by  dredges.  The  side  gulches 
of  the  main  streams  are  also  productive.  The  gold,  especially  of 
Eldorado,  is  coarse  and  rough,  with  numerous  nuggets  which  nearly 
always  contain  grains  and  fragments  of  quartz.  The  nuggets  are 
often  partially  crystallized,  the  common  form  being  bulky  octahedral 


486  NORTH     AMERICA. 

crystals.  The  average  value  of  the  gold  is  68s.  4d.  ($16.40)  per 
ounce  on  Bonanza  Creek,  and  less — 65s.  ($15.60) — on  Eldorado 
Creek. 

Hunker  Creek  resembles  Bonanza  Creek  in  its  general 
characters.  Its  principal  tributaries  are  Goldbottom  and  Last 
Chance  creeks.  The  latter  is  famous  for  the  great  quantity  of 
crystallized  gold  obtained  in  its  upper  course.  Its  gold  is  compara- 
tively low-grade,  being  worth  only  60s.  5d.  to  62s.  6d.  ($14.50  to 
$15.00)  per  ounce.  Other  auriferous  valleys  on  the  north  side  of 
the  region  are  Bear  Creek  and  Allgold  Creek.  The  former  flows 
directly  into  the  Klondike  river,  the  latter  falling  first  into  Plat 
Creek. 

On  the  south  side,  Dominion  Creek  is  the  most  important  of  those 
joining  the  Indian  river.  Like  most  of  the  other  streams,  its  gold 
high  up  its  valley  is  coarse,  rough,  and  nuggetty,  becoming  small, 
smooth,  and  waterworn  as  it  descends  the  stream.  Other  streams 
of  minor  importance  are  Gold  Run,  Sulphur,  Quartz,  and  Eureka 
creeks.  The  gold  from  the  last  is  very  coarse,  nuggets  varying  in 
weight  from  1|  to  3|  ounces  being  recorded.  The  largest  nugget  yet 
found  in  the  Klondike  district  weighed  85  ounces. a 

McConnell&  concludes  that  the  greater  part  of  the  Klondike 
gold  is  detrital  in  character  and  is  entirely  local  in  origin.  Numerous 
lenticular  auriferous  quartz-veins  seam  the  sericite-schists,  and  while 
the  great  majority  of  these  are  too  small  and  too  low-grade  to  be 
worked,  nevertheless  a  short  lens  of  quartz  found  at  the  head  of 
Victoria  Gulch  was  studded  at  one  end  with  numerous  grains  and 
small  nuggets  of  gold,  some  of  the  latter  being  well  crystallized 
and  very  like  those  found  in  the  gravels.  The  gold  was  only  at  or 
near  the  surface  of  the  vein,  little  being  in  the  interior  of  the  quartz. 
A  boulder  found  on  Bonanza  Creek  and  weighing  60  ounces  yielded 
no  less  than  20  ounces  gold.  A  small  quartz  vein  in  the  Victoria 
Gulch  mine  that  showed  no  visible  gold  yet  assayed  2,625  ounces 
gold  and  3,267  ounces  silver  per  ton!c  The  silicified  country  rock, 
mostly  sericitic  schists,  adjoining  the  auriferous  vein  was  also  found 
to  be  auriferous.  There  is  thus  ample  evidence  of  the  occurrence 
of  gold  in  the  local  veins.  Yet  not  all  of  the  alluvial  gold  is  detrital. 
In  Miller  Creek  a  boulder  was  found  whose  upper  surface  was  covered 
with  thin  specks  and  scales  of  crystallized  gold,  dendritically 
arranged.  The  boulder  itself  was  well  rounded,  while  the  gold- 
crystal  edges  were  sharp  and  unworn.  Similar  gold  has  been  obtained 
from  Eldorado  and  other  creeks. 

"  .Min.  Jour.,  Nov.,  1907. 

"  Loc.  cit.  sup.,  p.  61b. 

c  McConnell,  loc.  cit.,  p.  64b. 


YUKON.  487 

The  quartz  veins  are  often  pegmatitic  in  character,  inasmuch 
as  they  contain  occasional  felspar  crystals.  Such  veins  when 
followed  along  their  strike  have  been  seen  to  gradually  change  to  a 
normal  pegmatite,  as  described  by  Spurr  a  for  the  Fortymile  district 
in  Alaska.  In  other  quartz  veins  pyrite  and  magnetite  are  present 
with  rarer  chalcopyrite,  galena,  and  gold.  Pyrite  is  also  very 
common  in  the  alluvial  gravels.  The  Tertiary  sedimentaries  north 
of  Indian  river  have  attracted  considerable  attention  from  pros- 
pectors by  reason  of  their  contained  auriferous  conglomerates. 
These,  where  tested,  appeared  to  have  an  average  value  of  only 
9s.  4d.  ($2.24)  per  ton,  and  are,  of  course,  unworkable. 

Nearly  all  the  alluvial  gold  of  the  Klondike  accessible  to  the 
individual  miner  has  now  been  exhausted,  and  small  parties  of  men 
with  small  claims  have  been  superseded  by  large  and  wealthy 
companies  possessing  extensive  areas.  The  costly  primitive  methods 
of  sinking  and  drifting  with  subsequent  hand-sluicing  have  almost 
completely  been  abandoned.  In  their  place  an  extensive  use  is 
being  made  of  machinery.  The  gravels  are  moved  by  steam  scrapers, 
steam  shovels,  self -dumping  buckets  ("  Dawson  carriers  "),  and 
dredges.  The  latter  are  proving  successful,  their  chief  obstacle 
being  frozen  gravel.  By  an  extensive  use  of  "  steam  points  ' 
ahead  of  the  dredge,  this  difficulty  is  largely  overcome.  Lack  of 
.  water,  due  mainly  to  the  physiographic  isolation  of  the  auriferous 
area,  has  prevented  the  treatment  of  the  gravels,  and  especially 
of  those  of  the  White  Channel,  by  hydraulic  sluicing.  A  large 
amount  of  capital  is  now  being  expended  in  conserving  water, 
and  in  the  construction  of  long  water-races  both  to  command  the 
gravels  and  for  the  generation  of  electric  power.  It  is  therefore 
probable  that,  though  the  phenomenal  returns  of  the  past  may 
never  again  be  approached,  the  Klondike  region  will  produce  large 
quantities  of  gold  for  many  years  to  come.  To  reach  the  field 
the  arduous  and  dangerous  journey  of  the  late  'nineties  has  no 
longer  to  be  faced.  White  Horse,  below  the  notorious  rapids  of  the 
same  name  on  the  Lewes  river,  is  reached  after  a  railway  journey 
of  1 2  hours  from  Skaguay  at  the  head  of  Lynn  Canal.  From  White 
Horse  the  journey  to  Dawson  is  made  in  two  days  by  river  steamers. 
The  neighbourhood  of  Dawson  is  well  roaded,  and  working  costs 
are  thus  greatly  reduced. 

An  interesting  vein  occurrence  is  reported  from  the  Gold 
Reef  mine  near  Taku  Arm  to  the  west  of  Atlin  Lake,  South  Yukon. 
Dykes  of  greenish  porphyry  or  porphyrite  occur  near  the  eastern 
edge  of  a  narrow  band  (^-mile  wide)  of   schists.     In  this  disturbed 

"  18th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  3,  1898,  p.  87. 


488 


NORTH     AMERICA. 


area  are  situated  auriferous  veins  carrying  tellurides  of  gold  and 
silver  (sylvanite  and  hessite)." 

GOLD  PRODUCTION  OF  YUKON  TERRITORY. 


Year. 

Fine 
Ounces. 

Dollars. 

Sterling. 

Year. 

Fine 
Ounces. 

Dollars. 

Sterling. 

1885-6 

4,838 

SIOO.OOO 

£20,563 

1897 

120,948 

S2,500,000 

£513,929 

1887 

3,387 

70,000 

14,394 

1898 

483,793 

10,000,000 

2,<>56,120 

1888 

1,935 

40,000 

8,223 

1899 

774,069 

16,000,000 

3,289,793 

1889 

8,466 

175,000 

35,980 

1  1900 

1,077,649 

22,275,000 

4,580,008 

1890 

8,466 

175,000 

35,980 

1901 

870,827 

18,000,000 

3,701,014 

1891 

1,935 

40,000 

8,223 

1902 

701,500 

14,500,000 

2,981,375 

1892 

4,233 

87,500 

17,990 

1903 

592,646 

12,250,000 

2,518,745 

1893 

8,515 

176,000 

36,188 

1904 

507,983 

10,500,000 

2,158,927 

1894 

6,047 

125,000 

25,699 

1905 

402,864 

7,000,000 

1,435,000 

1895 

12,095 

250,000 

51,403 

1906 

270,882 

|  5,994,600 

1,228,893 

1896 

14,514 

300,000 

61,684 

1907 

3,15  ,000 

645,750 

$123,708,100 

£25,425,881 

UNITED    STATES    OF   AMERICA. 

The  United  States  had  been  for  long  the  greatest  gold-producing 
country  of  the  world.  It  now,  however,  occupies  second  position, 
being  surpassed  in  yield  by  the  enormously  rich  Witwatersrand 
field  of  the  Transvaal.  For  a  few  years  its  position  was  challenged 
by  Australasia,  whose  gold  output  was  then  being  augmented 
by  the  rich  mines  of  Kalgoorlie,  but  owing  to  the  decline  of  the 
Western  Australian  fields  and  the  discovery  of  the  rich  propylitic 
veins  of  Nevada,  the  United  States  has  of  late  easily  outdistanced 
its  southern  rival. 

Gold-mining  in  the  United  States  may  be  said  to  have  com- 
menced only  with  the  fourth  decade  of  the  nineteenth  century,  and 
its  enormous  gold  yield  of  £639,263,726  ($3,118,798,216)  is  therefore 
the  produce  of  only  some  77  years  of  mining  and  washing.  From 
1830  to  1850  the  veins  and  gravels  of  the  Southern  Appalachian 
States  supplied  much  of  the  gold  required  for  coinage,  but  Marshall's 
discovery  in  California  in  1849  speedily  shifted  the  centre  of  North 
American  gold-production  to  the  west  of  the  Rocky  Mountains, 
where  new  discoveries,  often  of  apparently  fabulous  richness,  have 
from  time  to  time  supplied  the  place  of  those  exhausted  and 
abandoned. 


a  Cairnes,  Jour.  Can.  Min.  Inst.,  Toronto,  1907 ;  quoted  Can.  Min.  Jour.,  April  15, 
1907,  p.  211. 


YUKON.  489 

As  pointed,  out  by  Lindgren  a  the  auriferous  vein  deposits  of  the 
United  States  may  be  grouped  in  three  divisions,  each  division  forming 
a  more  or  less  meridional  band.  These  divisions  are  well  separated, 
both  geologically  and  geographically.  The  Appalachian  belt  is  the 
oldest.  It  lies  between  the  Atlantic  coast  and  the  higher  ranges 
of  the  Appalachian  Chain,  and  may  be  said  to  extend  from  the  province 
of  Quebec  in  the  north  to  the  State  of  Alabama  in  the  south.  To 
be  associated  in  age  with  the  deposits  of  the  Appalachian  belt  are 
the  minor  occurrences  in  the  Lake  of  the  Woods  region  in  Minnesota, 
and  also  some  of  those  of  the  Black  Hills,  South  Dakota,  and  of  the 
State  of  Wyoming.  The  auriferous  veins  of  this  age  lie  mainly  in 
schists,  and  show  often  two  periods  of  auriferous  deposition.  Their 
placers,  especially  in  Georgia  and  in  the  Carolinas,  have  been  fairly 
productive.  The  general  age  of  these  beds  is  pre-Cambrian  or 
Algonkian. 

Next  in  age  but  separated  by  the  Palaeozoic  and  Mesozoic 
eras  in  time  and  by  the  width  of  North  America  in  position,  comes 
the  great  Pacific  belt  of  Cretaceous  veins,  extending  from  Alaska  to 
Lower  California.  The  time-gap  is  not  partially  bridged  in  the  United 
States,  as  it  is  in  Australia  and  to  a  minor  degree  in  Western  Europe, 
by  Permo-Carboniferous  or  later  auriferous  deposits,  probably  owing 
to  the  general  absence  of  volcanic  activity  in  North  America  during 
Palaeozoic  and  Mesozoic  times.  The  Pacific,  or  Sierra  Nevada 
belt  of  veins  lies  on  the  western  flanks  of  the  Sierra  Nevada  range 
and  shows  in  general  an  association  with  the  great  granodioritic 
and  dioritic  intrusions  that  form  the  core  of  the  Pacific  littoral 
uplift.  Veins  in  this  belt  are  normally  fissures  filled  with  quartz. 
Their  denudation,  though  they  are  themselves  often  low  in  grade, 
has  furnished  the  extremely  rich  Pliocene  and  recent  placers  of 
California. 

The  third  belt,  and  at  the  present  time  the  most  productive 
by  reason  of  its  bonanzas,  is  that  in  the  later  Tertiary  propylitic 
deposits  of  Nevada,  Utah,  Colorado,  and  New  Mexico.  It  has  a 
great  development  to  the  south  in  Mexico  and  reaches  as  far  north 
as  the  Owyhee  range,  in  Southern  Idaho.  Deposits,  generally 
containing  auriferous  veins,  of  the  same  nature  are  sporadic  along 
the  Cordilleran  uplift  in  Oregon  and  Washington,  and  after  a  great 
interval  on  Unga  Island,  in  the  Aleutian  Group,  Alaska.  The  later 
Tertiary  propylitic  deposits  are  characterised  by  a  general  prepon- 
derance of  silver  in  their  bullion,  and  by  the  presence  of  great  bonanzas 
(e.g.,  Cripple  Creek  and  Comstock).  The  placers  from  these  veins 
are  of  little  importance  owing  to  a  variety  of  causes,  of  which  the 

a  Trans.  Anier.  Inst.  M.E.,  XXXIII,  1903,  p.  790. 


490 


NORTH     AMERICA. 


small  degree  of  denudation  the  veins  have  suffered,  the  comparative 
aridity  of  the  Rocky  Mountain  region,  and  the  fineness  of  the  gold 
and  its  association  with  sulphides  and  tellurides  tending  to 
continuous  secondary  enrichment  of  the  outcrop  of  the  zone-vein, 
are  the  chief.  The  propylitic  vein  outcrops  indeed  represent 
the  original  upper  portions  of  the  fissures,  while  the  veins  of  the 
Pacific  and  Appalachian  belts  are  but  the  roots  of  original  veins 
that  have  been  denuded  to  depths  of  many  thousands  of  feet. 

The  general  direction  of  the  three  belts  is  due  to  the  axes  of 
regional  folding  and  of  mountain  building  being  more  or  less  meri- 
dional. In  the  case  of  the  Appalachian  uplift,  simple  erosion,  aided 
perhaps  by  faulting,  has  brought  the  Archaean  rocks  to  the  surface. 
Folding  along  the  Cordilleran  uplift  has  resulted  in  the  formation 
of  meridional  planes  of  crustal  weakness  along  which  igneous  magmas 
have  intruded  and  have  welled  forth  to  the  surface. 

The  total  gold  yield  of  the  United  States  cannot  be  stated  with 
any  degree  of  accuracy  owing  to  the  fact  that  only  since  1877  have 
statistics  been  systematically  collected.  Previous  yields  have  been 
estimated  by  various  authorities  with  widely  varying  results. 
In  the  following  compilation,  for  the  gold  yields  prior  to  1901,  the 
estimates  of  Lindgrena  have  been  followed,  and  for  those  sub- 
sequent to  1901,  the  figures  published  by  the  Geological  Survey & 
and  by  the  Director  of  the  United  States  Mint.c 


TOTAL  GOLD  YIELD  OF  UNITED  STATES, 

1792-1907. 

State. 

Value,  Dollars. 

Value,  Sterling. 

Alaska 

$121,348,200 

£24,896,880 

Appalachian  States 

49,020,906 

10,049,286 

Arizona 

66,226,931 

13,576,519 

California    . . 

1,503,447,536 

308,206,642 

Colorado 

424,066,234 

86,833,576 

Idaho 

122,736,655 

25,161,014 

Montana 

234.861,321 

48,146,569 

Nevada 

294,842,056 

60,442,619 

New  Mexico 

20,254,318 

4,152,134 

Oregon 

64,628,974 

13,248,937 

South  Dakota 

135,476,392 

27,762,659 

Utah 

57,185,608 

11,723,047 

Washington 

23,593,599 

4,836,806 

Wyoming    .  . 

1,107,486 

227,038 

Total  United  States     . . 

$3,118,798,216* 

£639,263,726* 

*  Including  estimated  figures  for  1907. 


a  Trans.  Amer,  Inst.  M.E.,  XXXIII,  1903,  p.  808. 
&Min.  Res.,  U.S.  Geol.  Surv.,   1901-1906. 
c Prelim.  Rep.,  Jan.,  1908. 


491 


ALASKA. 


The  earliest  discovery  of  gold  in  Alaska  appears  to  have  been 
made  by  the  Russian  engineer,  Doroshin,  as  long  ago  as  1849. 
Doroshin  was  unsuccessful  in  his  attempt  to  obtain  payable  results 
from  the  auriferous  alluvial  deposits  of  the  shores  of  Cook  Inlet,  and 
no  further  search  for  gold  was  made  for  many  years.  Mining  was 
indeed  actively  discouraged  by  the  Russian  fur-trading  companies, 
then  holding  possession  of  the  Alaskan  coast.  In  1866  Alaska  was 
sold  to  the  United  States  for  a  little  less  than  a  million  and  a  half 
sterling  ($7,200,000),  but  the  change  of  ownership  was  not  pro- 
ductive of  any  immediate  result.  In  1879  gold-quartz  veins  were 
found  near  Sitka,  and  gold-placers  in  the  Juneau  region  in  1880. 
The  working  of  the  latter  led  to  the  discovery  of  the  famous 
Alaska-Treadwell  lodes,  and  with  this  gold-mining  in  Alaska 
may  be  said  to  have  commenced. 

The  first  discovered  of  the  rich  gold-placers  of  the  Yukon  valley 
within  Alaskan  territory  was  the  Fortymile  (so  called  from  a  stream 
40  miles  below  old  Fort  Reliance).  The  field  was  worked  with  some 
vigour  from  1886,  the  year  of  its  discovery,  until  1897,  when  the 
reports  of  the  gold  of  Klondike  drew  most  of  its  miners  across  the 
international  boundary.  The  geological  conditions  prevailing  on 
the  Fortymile  stream a  are  very  similar  to  those  of  the  Klondike 
and  need  no  further  description  here.  Unlike  the  Klondike, 
however,  the  Fortymile  region  is  still  being  worked  by  small  parties 
and  by  individual  miners.  Near  Eagle,  25  miles  below  the  boundary, 
is  a  small  placer  area  of  no  great  present  importance.  Circle  City, 
175  miles  further  down  the  Yukon,  is  the  centre  of  the  Birch  Creek 
region,  for  long  and  perhaps  still  the  most  important  of  the  placer 
districts  of  the  interior  Yukon.  It  was  discovered  in  1893,  and  its 
annual  yield  in  1904  was  estimated  at  from  £30,000  to  £35,000 
($150,000  to   $175,000). 

The  town  of  Rampart  is  575  miles  below  the  boundary  and  is 
the  river  port  for  the  Rampart  auriferous  region.  The  creeks  of 
this  district  all  lie  within  30  miles  of  the  Yukon  river,  but  the  most 
southerly  flow  south  into  the  Tanana,  its  chief  Alaskan  tributary. 
On  the  northern  or  Yukon  slope  the  richer  creeks  are  the  Minook 
and  the  Troublesome.  These,  for  the  most  part,  flow  in  narrow 
valleys,  with  well-developed  "benches,"  or  old  high-level  gravels, 
on  the  valley  sides.  From  the  benches  much  of  the  gold  has  been 
obtained.  On  the  southern  slope  the  valleys,  especially  in  their 
lower  courses,  are  broader  and  more  open.  Baker  Creek  is  the 
best  known.     The  oldest  rocks  of  the  Rampart  region  are  garnet i- 

"Spurr,  18th  Ann.  Rep.  U.S.  Geo!.  Surv.,  Pt.  Ill,  1898,  p.  155. 


492  NORTH     AMERICA. 

ferous  quartz-mica-schists  with  calcareous  members,  but  the  greater 
part  of  the  bed-rock  of  the  country  is  formed  by  the  constantly 
associated  shales,  cherts,  conglomerates,  limestones,  tuffs,  and 
diabases  of  Devonian  age  that  have  collectively  been  termed  the 
Rampart  series. a  Granitic,  monzonitic,  and  diabasic  intrusions 
and  masses  are  numerous.  Both  gravels  and  "  muck  "  (peaty 
overburden)  are,  on  the  whole,  of  much  less  thickness  than  at 
Klondike.  An  interesting  occurrence  of  silver  nuggets  from  Ruby 
Creek  and  Slate  Creek  is  recorded. h  One  from  the  latter  stream 
weighed  8  ounces. 

A  hundred  miles  east  of  Rampart  lies  the  Fairbanks  region, 
one  of  the  latest  discovered  and  most  active  of  interior  Alaskan 
fields.  Its  yield  in  1904  was  some  £100,000  ($400,000).  The  chief 
producing  creeks  in  1903  were  Pedro,  Clery,  and  Fairbanks.  There 
are  here  no  high-level  gravels,  but  the  conditions  are  otherwise 
similar  to  the  majority  of  Yukon  districts. 

The  placer  districts  high  up  the  Koyukuk,  a  northern  tributary 
of  the  Yukon,  and  more  than  50  miles  within  the  Arctic  Circle,  are 
the  most  northerly  goldfields  in  the  world.  The  principal  mining 
centres  are  Bettles,  Peavy,  and  Cold  Foot.  Little  is  known  about 
this  region,  since  it  is,  naturally,  difficult  of  access.  The  placers 
of  the  Kobuk  river,  which  flows  into  Behring  Straits,  are  also 
well  within  the  Arctic  Circle. 

Seward  Peninsula. — By  far  the  richest  placers  of  Alaska,  are, 
however,  those  of  the  Seward  Peninsula.  They  occur  along  many 
streams  from  Kotzebue  Sound  on  the  north  to  Golofnin  Sound  on 
the  south,  and  in  streams  to  the  west  of  a  line  joining  these  Sounds. 
The  Nome  placers  are  the  best  known  and  at  the  present  time  the 
most  productive.  The  first  discovery  in  the  immediate  neighbour- 
hood of  Nome  was  made  on  Anvil  Creek  in  1898,  and  was  followed 
in  the  succeeding  year  by  that  of  the  Nome  beaches.  The  latter, 
for  three  miles  east  and  west  of  Nome,  have  yielded  a  rich  harvest 
and  have  been  worked  over  by  hand  twice  and  three  times.  They 
are  now  to  be  dredged.  At  Nome,  coastal  uplift  has  pro- 
duced three  main  lines  of  beach  gravel.  The  first  and  lowest  is 
the  present  beach,  the  second  is  37  feet  higher  and  three- 
quarters  of  a  mile  inland,  while  the  third  is  79  feet  above  sea-level 
and  five  miles  from  the  present  shore. c  The  present  beach 
is  made  up  of  sand,  fine  and  coarse  shingle,  angular  and  sub- 
angular  gravel,  and  a  few  large  boulders.     The  last  were  probably 

a  Spurr,  loc.  cit.  sup. 

6  Prindle  and  Hess,  Bull.  U.S.  Geol.  Surv.,  Xo.  259,  1905,  p.  11-1. 

c  Hutckins,  Eng.  Min.  Jour.,  Nov.  23,  1907. 


ALASKA.  493 

brought  to  their  present  position  by  floating  ice,  since  they  are 
generally  found  on  or  near  the  surface.  Strata  of  clay  sometimes  occur 
forming  "false  bottoms."  The  gold  occurs  irregularly  through  the 
deposit,  but  none  is  found  in  the  overlying  "tundra  "  or  muck — vege- 
table soil,  sand,  moss,  grass,  and  ice.  At  Nome  both  gravel  and 
overlying  "tundra"  are  generally  frozen,  though  unfrozen  areas,  due 
perhaps  to  springs  and  often  indicated  by  willows,  are  met  with.  As  a 
rule  the  beds  of  the  large  streams  are  not  frozen. a  Only  the  richest 
of  the  frozen  ground  may  be  worked.  Numerous  dredges  have  been 
placed  in  commission  in  Alaska,  but  the  majority  have  failed  owing 
to  weak  or  faulty  construction.  One  of  first-class  design,  placed 
on  the  Solomon  river  (east  of  Nome)  has  proved  successful.  Its 
working  costs  running  full  time  and  treating  3,000  cubic  yards 
per  day  are  estimated  at  6  grains  ($0.20)  per  cubic  yard.  The 
conditions  for  hydraulic  sluicing  methods  being  generally  favourable 
in  the  Seward  Peninsula,  considerable  use  is  made  of  giants  or 
monitors.  In  1904  it  was  estimated  that  there  were  no  less  than  275 
miles  of  water-races  constructed  or  under  construction.  During  that 
year  the  peninsula  produced  about  £900,000  ( $4,500,000)  gold.  Some 
of  the  low-lying  gravels  have  been  very  rich.  In  October,  1904, 
a  single  rocker  working  near  the  head  of  Little  Creek  recovered  in 
7  hours  200  pounds  weight  of  gold  ! & 

Other  important  placer  regions  in  the  Seward  Peninsula  are 
Solomon  river,  Bluff  district,  Casadepaga  river,  Council  district, 
Kongarok  river,  and  Fairhaven  district. 

In  southern  and  south-eastern  Alaska  placer  deposits  are 
not  of  great  importance.  Those  of  Turnagain  Arm,  Cook  Inlet,  are 
worked  by  hydraulic  methods.  They  were  the  first  discovered  in 
Alaska  and  are  interesting  as  yielding  nuggets  of  native  silver. 
As  might  be  expected,  the  bullion  is  low-grade,  ranging  from  62s.  6d. 
to  66s.  8d.  ($15  to  $16)  per  ounce.  The  gold  nuggets  from  this 
region  are  flat  and  smooth  with  occasional  glacial  striae.0  Near 
Cape  Yagtag,  400  miles  north-west  of  Sitka,  are  small  beach  placers 
that  have  been  worked  intermittently  and  yield  from  £2,000  to 
£3,000  ($10,000  to  $15,000)  per  annum.  The  best  returns  are 
always  after  the  heavy  winter  storms.  The  sands  are  garnetiferous 
and  the  gold  is  very  fine.^  Further  south-east,  placers  of  economic 
interest  are  those  of  Porcupine  Creek  near  Dyea,  Skaguay  district, 
and  of  Gold  Creek,  Juneau.     Owing  to  the  comparatively  recent 

a  Schrader  and  Brooks,  Rep.  U.S.  Geol.  Surv.,  Washington,  1900 
6  Brooks,  Bull.  U.S.  Geol.  Surv.,  No.  259,  1905,  p.  20. 
cMoffitt,Ib.,  p.  98. 
d  Martin,  lb.,  p.  89. 


494  NORTH     AMERICA. 

intense  glaciation  of  this  region  the  south-eastern  placers  are  of  no 
great  extent  and  the  majority  are  now  exhausted. 

Up  to  the  present,  valuable  quartz  veins  are  unknown  on  the 
northern  Alaskan  mainland.  On  the  Seward  Peninsula  a  quartz 
mine  has  been  opened  up  on  the  Big  Hurrah  tributary  of  the  Solomon 
river,  to  the  east  of  Nome.  Spurra  records  recent  propylitic 
mineralisation  from  the  Tordrillo  mountains  and  from  the  Skwentna 
and  Kuskokwim  rivers,  where  the  gold  deposits  are  apparently 
connected  with  Eocene  dykes,  generally  acidic  in  character. 

Aleutian  Islands. — The  islands  of  the  Aleutian  Chain  furnish 
two  gold-quartz  mines  in  andesites.  The  better  known  is 
the  Apollo  Consolidated  on  Unga  Island,  one  of  the 
Shumagin  group.  The  mine  lies  on  the  south  side  of  the 
island,  and  has,  since  1891,  yielded  between  £400,000  and 
£600,000  ($2,000,000  and  $3,000,000). h  The  lode  is  essentially 
a  zone  of  closely  reticulated  veins  in  a  large  mass  of  Tertiary 
andesite  or  dacite.  The  gangue  is  quartz  with  subordinate  amounts 
of  calcite  and  orthoclase.  Much  of  the  gold  is  free,  and  associated 
minerals  are  galena,  pyrite,  blende,  chalcopyrite,  and  native  copper. 
Minor  parallel  ore-bodies  occur  and  are  worked  on  either  side  of 
the  main  body.  Ore-shoots  occur  where  two  diagonal  sets  of  fractures 
intersect.  The  ore  varies  considerably  in  value,  averaging  perhaps 
33s.  4d.  ( $8.00)  per  ton.  A  small  beach  placer,  the  gold  of  which 
is  derived  from  similar  andesites,  is  worked  on  the  neighbouring 
Popoff  Island.  The  dark-grey  Tertiary  andesites  of  Unalaska 
Island,  where  volcanic  activity  is  still  persistent,  also  carry  low- 
grade  pyritous  lodes.    Workings  on  these  have  not  proved  profitable. 

South-Eastern  Alaska.  — The  auriferous  veins  of  south- 
eastern Alaska  occur  along  a  belt  extending  from  Berners 
Bay  in  the  north  to  Ketchikan  in  the  south.  The  outcrops 
of  the  various  geological  formations  along  this  belt  are 
disposed  in  bands  parallel  to  the  general  strike  of  the  strata 
and  to  the  north-west  trend  of  the  coast.  The  axial  rocks  of  the 
great  Coast  range  are  intrusive  diorites  and  granodiorites, 
which  are  themselves  occasionally  intruded  by  later  basic  rocks. 
There  are  also  contained  within  the  diorites  bands  of  metamorphic 
rocks  similar  to  and  probably  of  the  same  age  as  those  on  the  outer 
flanks  of  the  range.  The  diorites  are  of  various  types,  ranging  from 
hornblende-  and   mica-diorite  to  quartz-diorite   and  granodiorite. 

°20th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  7,  1900,  p.  259. 

h  Becker,  18th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  Ill,  1898,  p.  83  ;    Martin,  Bull.  U.S. 
Geol.  Surv.,  No.  259,  1905,  p.  100. 


ALASKA.  495 

The  albite-diorite  of  Becker a  probably  represents  an  extreme  phase 
of  differentiation  in  the  main  underlying  diorite-magma.  True 
granite  is  associated  with  the  diorite  in  the  north  of  the  belt  near 
Skaguay. 

Eastward  and  seaward  of  the  dioritic  mass  is  a  series  of  crystal- 
line schists  derived  from  sedimentary  rocks.  This  series,  along  a 
section  line  from  the  sea  across  Douglas  Island  to  the  main  range, 
is  about  three  miles  wide,  giving  an  apparent  thickness  of  strata  of 
about  15,000  feet.  Its  rocks  are  mainly  mica-,  hornblende-,  and 
garnet-schists,  such  as  might  result  from  the  metamorphism  of 
felspathic  and  calcareous  sandstones.  Associated  with  the  schists 
are  limestones  and  quartzites.  The  next  series  to  the  eastward  is 
composed  of  interbedded  slates  and  greenstones.  It  has  been 
divided  by  Spencer b  into  three  principal  lithological  groups,  with 
the  outermost  and  most  westerly  of  which  we  are  chiefly  concerned. 
It  is  this  group — made  up  of  alternating  bands  of  greenstone, 
greenstone-breccias,  and  black  calcareous  and  carbonaceous  slate  — 
that  forms  the  auriferous  horizon  of  the  Treadwell  deposits.  The 
whole  series  near  Douglas  Island  has  a  width  of  outcrop  of  some 
seven  miles.  It  is  considerably  metamorphosed,  the  black  slates  often 
becoming  graphitic.  By  Spencer  the  stratified  rocks  of  the  series 
are  referred  to  the  Carboniferous  period. 

While  the  lode-deposits  of  south-eastern  Alaska  follow,  as 
a  rule,  fairly  well-defined  geological  horizons,  they  nevertheless 
vary  greatly  in  character.  At  Berners  Bay,  Sitka,  and  Snettisham, 
the  auriferous  lodes  are  large  quartz  veins  of  only  moderate  grade. 
At  Sheep  Creek  and  Funter  Bay,  rich  gold-quartz  stringers  occur 
in  slates  and  schists.  In  the  Silver  Bow  basin,  behind  Juneau, 
gold-quartz  veins  follow  wide  basic  dykes.  In  many  places  quartz 
veins  are  not  developed,  and  the  lodes  are  then  heavily  mineralised 
belts  of  slate  and  schist.  In  the  Treadwell  district,  as  will  be  seen 
more  fully  in  later  pages,  the  lodes  are  shattered  albite-diorite  dykes. 

The  ore  for  which  the  lodes  of  the  Ketchikan  area,  in  the 
extreme  south  of  the  Alaskan  coastal  region,  are  worked,  is  mainly 
chalcopyrite,  containing  from  1|  to  2  dwts.  ($1.50  to  $2.00)  gold 
per  ton.  Gold-quartz  veins  also  occur  and  are  being  actively 
prospected.  In  the  Dolomi  area,  Johnson  Inlet,  36  miles  west  of 
Ketchikan,  numerous  gold-quartz  veins  occur  in  limestone  and  in 
calcareous  schists.  Similar  deposits  in  limestone  have  been  found 
on  Dall  Island.  At  the  Golden  Fleece  mine,  Dolomi,  the  dolomitic 
limestone  in  the  neighbourhood  of  the  auriferous  quartz  vein  is 
traversed  by  diabase  dykes.     At  the  Valparaiso  mine  in  the  same 

a  18th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  Ill,  1898,  p.  64,  et  seq. 
b  Spencer,  A.  C,  loc.  cit.  inf. 


496  NORTH     AMERICA. 

district  a  quartz-calcite  vein,  6  to  8  feet  wide,  in  crystalline  limestone 
is  worked.  With  the  free  gold  of  the  Valparaiso  vein  are  associated 
both  tetrahedrite  and  pyrite.° 

Spencer6  calls  attention  to  the  marked  resemblance  of  the 
Juneau  gold-belt  of  south-eastern  Alaska  to  the  Californian  gold 
belt:  "The  rocks  of  both  regions  are  in  part  of  identical  character,  and 
some  of  them  correspond  in  age  and  in  the  nature  of  their  metamor- 
phism.  There  is  also  a  marked  similarity  in  the  occurrence  of  the 
gold  veins  and  in  the  general  effects  of  mineralisation  ;  and  some 
of  the  broader  facts  suggest  that  the  dates  of  vein  and  ore-deposition 
correspond  closely,  though  more  definite  proof  of  this  is  required." 
The  Coast  Range  diorites  are  compared  with  those  of  the  Sierra 
Nevada  in  California  ;  the  Carboniferous  slates  of  Alaska  with  the 
Calaveras  formation  of  California  ;  and  the  greenstones  with  the 
amphibolites  in  the  vicinity  of  the  Mother  Lode. 

The  famous  Alaska-Treadwell  mines  are  situated  on  the  shore 
of  Gastineau  Channel,  which  separates  Douglas  Island  from  the 
mainland.  Juneau,  about  three  miles  north-east  of  the  mines  and 
across  Gastineau  Channel,  is  the  chief  township  of  the  district.  The 
Treadwell  deposits  were  first  worked  as  placer  diggings  about  the 
year  1881.  The  placers  were  rich,  but  small  and  shallow.  In  the 
same  year  a  small  mill  of  five  stamps  was  erected.  The  ore  even  then 
was  low-grade,  being  worth  only  from  32s.  to  40s.  ($8.00  to  $10.00) 
per  ton.  There  is  thus  evidence  of  the  absence  from  the  Treadwell 
lodes  of  notable  secondary  surface-enrichment.  The  extent  and 
tenor  of  the  ore-bodies  was  soon  recognised.  A  mill  of  120 
stamps  was  put  in  operation  in  1885  and  the  stamping  power  has 
gradually  been  increased  until  in  1906  there  were  no  less  than  880 
stamps  engaged  in  crushing  the  ore  of  the  four  Douglas  Island  mines, 
that,  under  one  management,  constitute  the  Treadwell  group.  These 
mines  have,  from  1882  to  1905  inclusive,  produced  £5,087,485 
($24,817,000)  gold.  Yet  the  ore  crushed  has  always  been  of 
exceedingly  low  grade,  that  mined  during  1903-4  being  valued 
at  only  a  little  more  than  $2.00  per  ton.  The  working  costs  in 
1907  were  5s.  6d.  ($1.33)  per  ton. 

It  has  already  been  said  that  the  Treadwell  ore-bodies  are 
shattered  albite-diorite  dykes  in  a  country  of  alternating 
carbonaceous  and  calcareous  slates  interbedded  with  greenstones. 
The  dykes  lie  in  a  zone  that  extends  for  three  miles  along  the  strike 
of  the  enclosing  rocks  and  possess  a  width  of  some  3,000  feet. 
The  hanging-wall  of  the  zone   is  sharply  defined  by  a  band  of 

a  Brooks,  Prof.  Paper,  U.S.  Geol.  Surv.,  No.  1,  1902,  p.  79. 
h  Trans.  Amer.  Inst.  M.E.,  XXXV,  1905,  p.  479. 


ALASKA. 


497 


greenstone  300  feet  thick,  dipping  with  the  country  to  the  north- 
east, and  therefore  towards  Gastineau  Channel.  The  strike 
of  the  greenstone  is  slightly  oblique  to  the  shore,  and 
towards  the  south-east  the  greenstone  outcrop  disappears 
beneath  the  channel  waters.  The  greenstone,  according  to  Spencer, 
is  almost  certainly  interbedded  with  the  slates,  and  is  not 
intrusive  into  them.  To  the  north-west  it  appears  as  a  fine- 
grained diabase  but,  near  its  point  of  disappearance  beneath 
Gastineau  Channel,  it  becomes  coarser  and  more  granular,  with 
coarsely  crystallized  hornblende  and  some  pyrite.  The  albite- 
diorites  are  much  younger  than  and  are  intrusive  through  the 
greenstone.  While  the  diorite  dykes  far  away  from  the  hanging- 
wall  greenstone  have  been  heavily  mineralised,  it  is  only  when  they 


TT?r^::^yr-^:::-r: 


Diorite     Black  Slate     Schist       Greenstone 


Figs.   158  axd  159.     Geological  Plan  and  Section  of  Neighbourhood  of  Juneau,  Alaska 

(Spencer). 

lie  immediately  under  the  hanging- wall  that  they  become  sufficiently 
valuable  to  be  worked.  The  original  albite-diorite  of  the  lodes 
is  now  much  altered.  The  primary  felspars  were  albite-oligoclase 
with  microperthite.  Secondary  felspars  are  pure  albite.  Few 
traces  of  original  ferro-magnesian  silicates  remain.      Thin   basaltic 


HI 


4<»S 


NORTH     AMERICA. 


dykes  are  the  youngest  rocks  of  the  district.      These  are  believed 
to  have  no  genetic  connection  with  the  ore-deposits. 

The  lodes  vary  in  width  from  a  few  inches  to  200  feet. 
The  ore  consists  essentially  of  albite-diorite  rock  impregnated 
with  pyrite  and  other  sulphides,  and  reticulated  with  pyritous 
quartz  and  calcite  veinlets.  The  sulphides  present  are  pyrite, 
stibnite,  and  pyrrhotite,  with  rarer  chalcopyrite,  galena,  blende, 
and  molybdenite.  Magnetite  occurs  in  some  quantity.  Arsenic, 
realgar,  and  orpiment  have  been  detected.  The  presence  of  molyb- 
denite is  said  to  indicate  higher-grade  ore.  From  60  to  75  per  cent,  of 
the  gold  is  free  milling.  The  concentrates,  constituting  2  per  cent, 
of  the  ore  crushed,  are  worth  from  £6  to  £10  ($30  to  $50)  per  ton. 
Gold  is  very  rarely  visible.  The  ore-dykes  have  already  been 
mined  to  depths  of  more  than  1,000  feet. 

The  sulphide-filling  of  the  cross  veinlets  within  the  dykes 
appears  to  be  due  to  metasomatic  replacement,  the  original  horn- 
blende and  mica  having  completely  disappeared  and  the  secondary 
albite  being  largely  replaced  by  sulphides.  Further  evidence  of 
metasomatic  replacement  may  be  derived  from  the  fact  that  the 
ore-filling  of  the  cross  veinlets  does  not  pass  beyond  the  foot  and 
hanging-walls  of  the  diorite  dykes,  though  the  fissures  themselves 
may  be  traced  into  the  adjoining  slates. 

The  following  table  shows  the  annual  value  of  the  gold  pro- 
duction of  Alaska  since  the  year  1880  :  —  a 


Year. 

Value,  Dollars. 

Value,  Sterling. 

Year. 

Value,  Dollars. 

Value,  Sterling. 

1880 

$  20,000 

£4,100 

1894 

S  1,282,000 

£  262,810 

1881 

40,000 

8,200 

1895 

2,328,000 

477,342 

1882 

150,000 

30,750 

1896 

2,861,000 

586,505 

1883 

301,000 

61,705 

1897 

2,439,500 

499,995 

1884 

201,000 

41,205 

1898 

2,517,000 

515,985 

1885 

300,000 

61,500 

1899 

5,602,000 

1,148,410 

1886 

446,000 

91,430 

1900 

8,166,000 

1,674,030 

1887 

675,000 

138,375 

1901 

6,932,700 

1,421,203 

1888 

850,000 

174,250 

1902 

8,283,400 

1,698,097 

1889 

900,000 

184,500 

1903 

8,683,600 

1,780,138 

1890 

762,000 

156,210 

1904 

9,160,000 

1,877,800 

1891 

900,000 

184,500 

1905 

15,630,000 

3,204,150 

1892 

1,080,000 

221,400 

1906 

21,800,000 

4,469,000 

1893 

1,038,000 

212,790 

1907 

18,000,000| 

3,690,000f 

Tota 

1 

§121,348,200 

£24,896,880 

t  Estimated. 


a  Brooks,  Rep.  Min.  Res.  Alaska,  1907,  Bull.  No.  314,  U.S.  Geol.  Surv.,  p.  21. 


499 

WASHINGTON. 

Two  main  auriferous  belts  are  found  in  this  State  :  a  central 
belt  extending  along  the  trend  of  the  Cascade  Mountains,  and  an 
eastern  belt,  the  southern  continuation  in  Ferry  and  Stevens  counties 
of  the  already  described  regions  of  Rossland  and  Slocan  in  British 
Columbia.  In  the  former  region  the  Cascade  Mountains,  which 
reach  their  highest  altitude  in  Mount  Tacoma  or  Rainier  (14,530 
feet),  are  made  up  of  Palaeozoic  and  Mesozoic  sedimentary  rocks, 
intruded  and  often  covered  by  granodiorite  and  diorite  of  Mesozoic 
and  Tertiary  age.  The  geological  features  are  therefore  closely  akin 
to  those  of  the  Coast  range  in  British  Columbia  in  the  north,  and 
to  those  of  the  Sierra  Nevada  in  California  in  the  south.  On  the 
Cascade  belt  the  principal  mining  field  is  at  Monte  Cristo,  40  miles 
west  of  Everett  and  of  Puget  Sound.  The  rocks  of  Monte  Cristo 
are  entirely  Tertiary. a  The  oldest  are  arkoses  and  conglomerates 
derived  from  neighbouring  Mesozoic  granodiorites.  These  are 
overlain  by  andesite,  tonalite  (ranging  to  dacite),  rhyolite,  and  basalt, 
of  Miocene  age,  through  which  is  intruded  late  Pliocene  pyroxene- 
hornblende-andesite.  The  period  of  ore-deposition  is  apparently 
Pleistocene.  The  minerals  associated  with  the  silver-gold  of  the 
veins  are  pyrite,  pyrrhotite,  arsenopyrite,  blende,  galena,  and 
chalcopyrite,  with  rare  chalcocite,  bornite,  molybdenite,  and 
stibnite.  Metallic  arsenic  has  been  found  in  the  neighbourhood. 
The  average  content  per  ton  of  the  Monte  Cristo  ores  is  0  •  6  ounce 
gold  and  7  ounces  silver  per  ton.  The  gangue  is  quartz  with 
occasional  calcite.  The  veins  are,  on  the  whole,  characterised  by 
a  remarkable  persistency  and  regularity  in  extension.  The  milling 
ore,  however,  occurs  in  irregular  pay-shoots. 

In  the  Mount  Baker  district  further  north  and  near  the  inter- 
national boundary  the  veins  are  also  associated  with  late  igneous 
rocks.  They  are  copper-gold  lodes  and  carry  undetermined  gold 
tellurides.& 

South  of  Monte  Cristo  lie  the  Peshastin  and  Sauk  districts, 
best  known  for  their  alluvial  gold.  The  country  of  the  gold-quartz 
veins  of  the  former  is  altered  Mesozoic  peridotite  or  serpentine, 
and  of  the  latter,  the  Sauk  (Eocene)  sandstones  and  shales.  In  many 
cases  a  diabase  dyke  intrusive  through  the  sedimentary  rocks 
forms  one  wall  of  the  quartz  vein.  In  other  cases  the  quartz  veins 
lie  wholly  within  the  diabase  dykes.  In  a  specimen  from  the  Gold 
Leaf  mine  in  this  district  perfect  octahedral  crystals  of  gold  lie 
on  the  ends  of  the  quartz  crystals.0    From  the  foregoing  illustration 

aSpurr,  22nd  Ann.  Rep.  U.S.  Geol.  Surv.,  1901,  Pt.  II,  p.  788. 
"  Landes,  Rep.  Wash.  Geol.  Surv.,  Olympia,  1902,  p.  40. 
c  Smith,  G.  O.,  Bull.  U.S.  Geol.  Surv.,  No.  213,  1903,  p.  80. 


500 


NORTH    AMERICA. 


of  vein  occurrences  in  the  Cascade  Mountains  it  will  be  clear  that 
while  the  geological  relations  of  the  enclosing  rocks  are  similar 
to  those  of  the  Sierra  Nevada  in  California,  the  gold-quartz  veins 
are  themselves  much  younger  than  those  of  California,  and  are, 
indeed,  probably  no  older  than  late  Tertiary. 

The  mines  of  Stevens  and  Ferry  counties  in  the  north-eastern 
corner  of  the  State  present  considerable  resemblances  to  those  of  the 
Rossland  district.  The  oldest  rocks  of  the  Republic  district  in 
Ferry  county  are  granite,  gneiss,  crystalline  schist,  and  limestone. 
Through  these,  granites  have  been  intruded.  In  early  Tertiary 
times  there  occurred  extensive  porphyritic  andesite  flows,  in  which 
the  principal  veins  of  the  district  were  formed.  The  gangue  is 
clean  quartz  without  sulphides,  and  the  gold  is  ordinarily  so  fine 
that  it  cannot,  even  in  rich  specimens,  be  detected  with  a  lens. 
Nevertheless,  the  values  of  different  portions  of  the  same  veins 
may  vary  considerably.  In  Stevens  county,  the  Pierre  Lake  is 
the  principal  district.  Its  rocks  are  also  gneisses  and  crystalline 
schists. 

Nearly  all  the  terraces  and  bars  of  the  upper  Columbia  river 
in  Washington  State  carry  fine  gold.  Most  of  the  richer  spots  have 
been  discovered  and  worked  by  Chinese,  but  it  is  considered  that 
there  may  yet  remain  limited  areas  sufficiently  rich  to  warrant 
the  use  of  dredges." 

Beach-placer  mining  has  been  intermittently  conducted  since 
1864  on  the  Pacific  Coast  on  beaches  lying  from  10  to  25  miles  south 
of  Cape  Flattery.  The  yield  has  never  been  large  and  is  estimated 
at  a  total  of  £3,000  ($15,000). b  The  gold  is  concentrated  by  wave- 
action  from  cliffs  and  terraces  of  Pleistocene  sands  and  gravels. 
Small  quantities  of  platinum  and  iridosmine  occur  with  the  gold. 

The  total  yield  of  Washington  State  since  the  discovery  of 
gold  to   1900  inclusive  is  estimated  at  £4,387,000   ($21,400,000). 

The  yield  for  recent  years  is  : — 


Year. 

Value,  Dollars. 

Value,  Sterling. 

1901 

$580,500 

£119,002 

1902 

272,200 

55,801 

1903 

279,900 

57,380 

1904 

314,463 

64,465 

1905 

370,000 

75,850 

1906 

221,648 

45,438 

1907 

154.888 

31,870 

Grand  Total  to 
end  of  1907. 

$23,593,599 

£4,836,806 

"  Collier,  Bull.  U.S.  Geol.  Surv.,  No.  315,  1907,  p.  70. 
6  Arnold,  lb.,  No.  260,  1905,  p.  155. 


501 


OREGON. 


Two  distinct  and  well-separated  auriferous  areas  are  found 
in  the  State  of  Oregon,  one  in  the  Blue  Mountains  in  the  north-east, 
the  other  in  the  south-west,  where  it  forms  the  northern  prolongation 
of  the  auriferous  belt  of  California.  The  first  is  the  more  important. 
It  covers  a  considerable  area,  extending  the  length  of  the  Blue 
Mountains,  with  a  width  westward  from  the  Snake  river  of  some 
130  miles.  Its  placers  were  known  first  in  1862.  For  several  years, 
and  especially  in  the  neighbourhood  of  Auburn,  they  yielded 
handsome  profits,  notwithstanding  the  fact  that  the  early  miners 
had  each  to  recover  at  least  $8.00  gold  per  diem  to  cover  bare  living 
expenses.  By  1870  the  richest  placers  were  exhausted  and  a 
gradual  decline  in  placer-mining  has  continued  to  the  present  day. 
In  1885  a  railroad  was  constructed  through  the  region,  and  the  active 
development  of  the  gold-quartz  veins  dates  from  that  year. 

The  Blue  Mountains  may  be  regarded  as  the  western  portion 
of  the  great  central  mountain  mass  of  Idaho.  They  are  made  up 
of  cores  of  Palaeozoic  rocks  partly  surrounded  by  later  Tertiary 
lavas — rhyolites,  andesites,  and  basalts. a  The  oldest  rocks  are 
siliceous  argillites  of  possibly  Carboniferous  age.  Overlying  them 
come  Triassic  shales  and  limestones.  In  many  places  the  sedimentary 
rocks  are  disrupted  and  folded  by  intrusive  masses  of  granite, 
granodiorite,  diorite,  gabbro,  and  serpentine.  The  area  is  considered 
by  Lindgren  to  resemble  closely  in  its  general  geological  features 
the  auriferous  belt  of  the  Sierra  Nevada  in  California.  The  gold- 
silver  veins  of  the  Blue  Mountains  occur  within  a  belt  100  miles  in 
length  and  30  to  40  miles  in  breadth,  and  from  this  restricted  area 
the  placer-deposits  ramify  through  the  lower  country.  The  principal 
veins  lie  in  Baker  and  Grant  counties.  Their  country  is  either  the 
granodiorite,  an  associated  igneous  rock  (diorite  or  tufaceous 
greenstone),  or  the  argillite.  Most  of  the  larger  and  richer  mines 
are  in  the  latter.  It  would  therefore  appear  that  here,  as  in 
California,  the  enclosing  country  exercises  no  potent  influence  on 
the  richness  or  otherwise  of  the  vein.  But  there  is  nevertheless  a 
genetic  connection  between  the  intrusive  rocks  and  the  gold-quartz 
since  the  veins  are,  speaking  broadly,  grouped  on  one  or  other 
side,  or  on  both  sides,  of  the  contacts  of  the  intrusive  rock  (which 
ranges  from  granite  to  serpentine)  with  the  sedimentary  members 
of  the  complex.  In  age  the  veins  are  probably  Cretaceous.  Their 
gangue  is  quartz  with  occasional  calcite  or  dolomite.  Gold  occurs 
both  free  and  with  sulphides. 

The  placer-deposits  of  north-eastern  Oregon  are  at  the  present 
day  comparatively  unimportant.   The  bars  of  the  Snake  river,  which 

a  Lindgren,  22nd  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  II,  1902,  p.  576. 


502  NORTH    AMERICA. 

forms  the  boundary  between  Oregon  and  Idaho,  carry  fine  gold,  and 
small  gulch  deposits  are  being  worked  in  the  head -waters  of  the 
tributaries  of  the  Grande  Ronde,  Powder,  Burnt,  and  Malheur 
rivers,  all  flowing  east  to  join  the  Snake,  and  in  the  upper  tributaries 
of  the  John  Day  river,  flowing  west  from  the  Blue  Mountains  and 
falling  into  the  Columbia  river.  The  placer-deposits  are  of  widely 
differing  ages.  Early  Miocene,  or  possibly  even  Pliocene,  gravels 
have  been  covered  up  by  the  great  flows  of  later,  mainly  Miocene, 
lavas.  For  the  most  part  these  ancient  auriferous  channels  lie 
below  the  present  drainage  level  of  the  country  and  are  inaccessible. 
Similar  gravels  have,  however,  been  worked  at  Winterville  and 
Parkerville  at  the  head  of  Burnt  river.  Gravels  of  intervolcanic 
(later  Miocene)  age  are  found  as  benches  or  high-level  gravels  at 
Sumpter,  Canyon,  and  elsewhere.  Pleistocene  gravels  occur  as 
low  benches  or  occupy  the  present  drainage  channels.  On  the 
whole  the  gold  is  coarse,  but  exceedingly  fine  gold  is  found  when 
the  distance  from  its  original  source  becomes  considerable.  The 
quality  of  the  placer-gold  varies  from  680  to  990,  the  percentage 
of  silver  naturally  decreasing  with  the  size  of  the  gold  grains. 
The  largest  nugget  found  in  the  area  is  said  to  have  come 
from  McNamee  Gulch,  near  Robinsonville.  It  is  reported  to  have 
been  worth  £2,800  ($14,000),  and  its  weight  was  therefore  at  least 
700  ounces.  Working  costs  show  that  in  this  area  hydraulic  sluicing 
requires  at  least  1£  grains,  and  dredging  at  least  5  to  6  grains  gold 
per  cubic  yard  to  cover  expenses. 

In  south-western  Oregon  gold-quartz  veins  are  found  in  Lane, 
Douglas,  Curry,  Josephine,  and  Jackson  counties.  The  Bohemia 
mining  district  described  by  Diller a  is  apparently  typical  of  these 
occurrences.  The  district  lies  on  the  Calapooya  Mountain,  a 
western  spur  of  the  Cascades.  The  mountain  mass  is  made  up 
of  Eocene  and  Miocene  lavas,  such  as  are  common  through  the 
whole  Cascade  chain,  and,  indeed,  form  its  highest  mountains 
[Rainier  (Tacoma)  and  Shasta].  The  lavas  are  dacite-porphyry, 
andesite,  and  basalt.  They  are  now  considerably  propylitised. 
The  veins  lie  in  narrow,  irregular,  crushed  and  mineralised  zones. 
Pyritous  impregnation  often  extends  6  feet  and  more  on  each  side 
of  the  original  fissure.  The  gangue  is  mainly  quartz  with  kaolinic 
and  sericitic  matter.  The  gold  is  free  or  is  associated  with  pyrite, 
blende,  galena,  and  chalcopyrite. 

Fifty  miles  north  of  the  Bohemia  district  is  the  Blue  River 
goldfield.  Its  rocks  are  more  acid  than  those  of  Bohemia,  rhyolite 
being  abundant.     Andesites  and  basalts,  however,   occur. 

a20th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  Ill,  1900,  p.  11. 


OREGON. 


503 


Most  of  the  placer  gold  of  Oregon  is  obtained  in  Josephine 
county,  and  is  derived  from  veins  similar  to  those  just  described. 
The  largest  alluvial  gold  mine  at  present  working  in  south-eastern 
Oregon  is  the  Greenback,  in  Josephine  county.  Beach  placers, 
arising  from  the  action  of  waves  on  gravel  cliffs,  have  been  worked 
near  Cape  Blanco  and  Port  Orford.    Their  yield  is  small. 

The  total  production  of  gold  of  the  State  of  Oregon  from  the 
year  of  its  discovery  to  1900  is  estimated  at  £11,172,500  ($54,500,000). 
Subsequent  annual  yields  have  been  :  — 


Year. 

Value,  Dollars. 

Value,  Sterling. 

1901 

$1,818,100 

£372,710 

1902 

1,816,700 

372,421 

1903 

1,290,200 

264,491 

1904 

1,412,186 

289,498 

1905 

1,244,900 

255,204 

1906 

1,366,900 

280,216 

1907 

1,179,988* 

241,897 

Grand  Total. 

$64,628,974 

£13,248,937 

*  Estimated. 

CALIFORNIA. 

The  gold  belt  of  California  extends  along  the  western  foothills 
of  the  Sierra  Nevada  and  for  some  distance  beyond  them  to  the 
south.  It  may  be  described  as  commencing  in  Mexico  100  miles 
south  of  the  State  boundary  line  and  passing  up,  by  way  of  San 
Diego,  San  Bernardino,  and  Kern  counties,  to  the  foot  of  the 
Sierra  Nevada,  where  it  develops  breadth  and  richness,  forming, 
along  the  western  flanks  of  the  Sierra  Nevada  to  Tehama 
county,  the  main  central  portion  of  the  gold  belt.  In  Tehama 
county  it  disappears  beneath  the  great  lava  fields  of  Northern 
California.  The  general  width  of  the  belt  is  from  20  to  60  miles  ; 
the  greatest  width  is  attained  in  and'  to  the  north  of  Mariposa 
county.  The  belt  is  probably  continued  by  the  gold  occurrences 
of  the  northern  counties  of  Shasta,  Trinity,  and  Siskiyou,  and 
further  north,  as  has  already  been  indicated,  by  some  of  the  gold 
veins  of  Southern  Oregon. 

A  second  and  very  dissimilar  belt,  orographically  and  geologi- 
cally belonging  to  Nevada  rather  than  to  California,  occurs  on  the 
eastern  flank  of  the  Sierra  Nevada  in  Tertiary  andesitic  regions. 
It  passes  from  south-east  to  north-west  through  San  Bernardino, 
Inyo,  Mono,  and  Alpine  counties. 

The  rock-core  of  the  Sierra  Nevada  and  of  its  geological 
extension  into  Lower  California  is  a  granodiorite  (quartz-mica- 
diorite  containing  a  little  orthoclase)  which  is  intrusive    into  the 


504  NORTH    AMERICA. 

great  complex  termed  the  "  metamorphic  series  "  or  "  auriferous 
slate,"  though  the  latter  is  well  developed  only  in  the  north  of  the 
auriferous  area.  The  metamorphic  series  consists  largely  of  more 
or  less  altered,  highly  compressed  and  folded  sediments  ranging 
in  age  from  early  Palaeozoic  to  late  Jurassic.  Through  these  are 
intruded  igneous  masses  also  of  varying  ages  from  Palaeozoic  to 
Mesozoic,  but  mainly  of  late  Jurassic  or  early  Cretaceous  time. 
In  the  intrusive  rocks  augite-porphyrite,  diabase,  and  serpentine 
all  find  representatives.  The  older  rocks  have  shared  in  the  orogenic 
movements  that  initiated  mountain  building  and  are  therefore 
largely  converted  into  crystalline  schists. a  The  sedimentary  rocks 
occur  mainly  in  the  eastern  or  higher  portion  of  the  metamorphic 
belt,  the  igneous  in  the  western  or  lower  portion.  The  last  intrusions 
through  the  metamorphic  series  are  apparently  apophyses 
from  the  great  granodioritic  central  core. 

The  auriferous  area  is  closely  connected  with  the  metamorphic 
series,  their  respective  boundaries  being  practically  coincident. 
Even  in  the  far  south,  where  the  granodiorite  is  widely  developed, 
the  scattered  gold  deposits  are  usually  found  to  be  connected  with 
small  schistose  areas.  Gold-quartz  veins  are  uncommon  in  the 
granodiorite,  and  when  they  do  occur,  they  are  generally  near 
a  contact  with  the  metamorphic  series.  Within  the  latter,  however, 
they  may  and  do  occur  in  any  given  member  of  the  complex,whether 
metamorphic,  sedimentary,  or  igneous.  While  no  increase  in  the 
number  or  in  richness  of  the  veins  is  noticeable  near  the  main  line 
of  contact  of  the  granodiorite  and  metamorphic  series,  yet,  within 
the  latter,  gold-quartz  veins  are  very  often  found  clustered  along 
the  granodiorite  dyke  contacts.  Lindgren  &  at  first  insisted  that 
the  California  gold-quartz  veins  showed  no  remarkable  dependence 
on  acid  igneous  rocks,  but  in  1903  a  general  genetic  relation  was 
admitted,  although  few,  including  the  great  Mother  Lode,  for 
example,  can  be  shown  to  be  directly  dependent  on  these 
granodioritic  apophyses.  Gold-quartz  veins  are  also  known  to 
occur  in  areas  of  diabase  and  of  augite-porphyrite  far  removed 
from  other  rocks. 

The  period  of  filling  of  the  gold-quartz  veins  of  California  is 
believed  to  be  late  Jurassic  or  early  Cretaceous.  The  filling  itself 
is  probably  due  to  thermal  or  solfataric  action,  consequent  on 
granodioritic  or  magmatically  connected  intrusions.  According 
to  Lindgren  some  deposits  are  perhaps  even  earlier,  since  in  the 
uppermost  member  of  the  series  certain  Jurassic  conglomerates 
carry  gold  believed  to   be  placer  in  origin. c 

£  Lindgren,  Bull.  Geol.  Soc.  Amer.,  VI,  1895,  p.  224. 

b  Loc.  cit.,  p.  225. 

c  Lindgren,  Amer.  Jour.  Sci.,  XLVIII,  1894,  p.  275. 


CALIFORNIA. 


505 


The  normal  gold-quartz  veins  of  California  are  fissure  veins 
that  are  subsequent  in  age  to  the  metamorphism  of  the  slates,  &c. 
Unlike  the  normal  lenticular  bedded  veins  of  schistose  rocks,  the 
typical  gold-quartz  veins  of  California  run  indifferently  across  or 
with  the  strike  or  dip  of  the  slates  and  schists.  In  the  massive 
rocks  (diabase,  granodiorite,  or  gabbro)  no  rule  is  observable. 
The  great  Mother  Lode  itself  is  parallel  with  the  strike  of  the 
enclosing  rocks  but  cuts  across  the  dip. 

The  quartz  veins  have  been  formed  by  simple  filling  of  fractures 
and  fissures,  wall-replacement  having  apparently  played  no  part  in 
their  development.  The  quartz  is  white  and  milky.  Calcite, 
mariposite  (green  chromium-potash-mica),  roscoelite  (vanadium- 
potash-mica),  rhodonite,  and  albite  occasionally  occur  in  thegangue. 
Free  native  gold  is  irregularly  distributed  in  the  matrix,  and  in 
vughs  is  often  crystallized.  Pyrite,  chalcopyrite,  blende,  galena, 
and  arsenopyrite  are  common  associates  of  the  gold,  while  pyrrhotite, 
molybdenite,  tetrahedrite,  cinnabar,  and  various  tellurides  occur 
more  rarely.  It  appears  to  be  the  rule  that  veins  in  granodiorites 
contain  more  sulphides  than  those  in  other  rocks,  and  pyrrhotite 
is  found  only  in  these  rocks.  The  pay-ore  is  ordinarily  contained 
in  shoots  following  an  empirical  law  which  is  nevertheless  of  very 
wide  application,  viz.,  that  the  shoots  pitch  to  the  left  when  the 
observer  is  looking  down  the  dip  of  the  vein.  Rich  pockets  or 
bonanzas  are  often  met  with  at  the  intersection  of  two  veins. 


Quartz.  M; 


Fig.  160.     Section'  across  Mother  Lode  at  Quartz  Mount  (Fairbanks). 


In  addition  to  the  normal  type  of  simple  gold-quartz  vein,  low- 
grade  auriferous  zones  of  pyritous  impregnations  are  found  in 
amphibolitic  schists.  Quartz  veins  passing  through  these  may 
be  strongly  enriched.  These  deposits  are  distinctly  older  than 
the  principal  quartz  veins  and  are  contemporaneous  with  the 
metamorphism  of  the  diabase  to  schists.  Later  impregnations 
of  the  schists  and  massive  rocks  with  auriferous  pyrite  have  also 
been  noted. 


506 


NORTH    AMERICA. 


The  Mother  Lode. — The  most  remarkable  auriferous  lode  in 
California  and,  indeed,  in  some  respects,  in  the  world,  is  the 
famous  Mother  Lode,  that  extends  northward  from  Mount 
Ophir  in  Mariposa  county  to  beyond  Calaveras  county,  a  total 
distance  of  more  than  a  hundred  miles.  Properly  speaking, 
it  is  not  a  true  lode,  but  rather  a  sheared  and  fissured  zone  in 
which  numerous  quartz  veins  and  stringers  are  developed.  Its 
strike,  as  already  noted,  is  north-west  and  south-east,  i.e., 
with  the  country.  In  many  places  it  forms  a  single  lode 
varying  in  width  from  a  few  feet  to  more  than  100  feet.  The 
maximum  width  of  the  formation  is  about  a  mile.  Owing  to  the 
greater  resistance  to  erosion  of  the  quartz  it  often  stands  out  above 


Fig.  161.     Plax  of  Mother  Lode,  kear  Cottlterville  (Storms). 

the  level  of  the  county  as  a  great  white  wall.  When  followed  in 
depth  it  shows  neither  diminution  in  size  nor  decrease  in  value. a 
The  Mother  Lode  is  associated  with  a  narrow  and  almost 
continuous  belt  of  black  slate,  called  the  Mariposa  beds.  The 
contained  veins  occur  either  in  the  slate  or  on  the  contact 
between  it  and  the  greenstone  (diabase)  dykes.  The  regularity 
and  continuity  of  the  lode  are  due  largely  to  the  geological 
structure.  At  Quartz  Mount,  Calaveras  county,  the  lode  is  600 
feet  wide.  Here,  however,  and  for  some  distance  north  and 
south,  there  are  really  two  principal  veins  with  intervening  country. 
In  Amador  and  Eldorado  counties,  the  lode  splits  into  a  series  of 
parallel  veins.     The  Mother  Lode  is  undoubtedly  due  to  major 


c  Fairbanks,  10th  Ann.  Rep.  State.  Min.,  Cal.,  1890,  p.  23  ;  Id.  ib.,  1896,  p.  666. 


CALIFORNIA. 


507 


faulting  developed  along  a  line  parallel  with  the  axis  of  the  Sierras 
during  the  uplift  of  those  mountains.  The  whole  length  of  the 
lode  cannot  be  worked  at  a  profit,  but  the  erosion  of  even  the  poorer 
parts  has  nevertheless  resulted  in  rich  placer-deposits.  Some  zones 
have  been  particularly  rich,  as  at  Grass  Valley  and  Nevada,  and 
in  that  portion  of  the  Mother  Lode  belt  in  Tuolumne  county.  The 
quartz-bodies  forming  the  ore-shoots  occur  in  lenticular  masses 
that  range  from  a  few  inches  to  50  feet  in  thickness,  and  extend 
for  over  1,000  feet  along  the  strike.     The  lenses  are  irregularly 


Fig.  162.     Geological  Map   of  Neighbourhood   of  Grass  Valley  and  Nevada  City, 

California  (Lindgreri). 

1.  Mesozoic  and  Upper  Pala?ozoic  sedimentary  bed?.      2.  Granodiorite. 
3.  Diabase,  porphyrite,  gabbro,  diorite,  serpentine,  and  ampbibolite.     +  Gold-quartz  mines. 


distributed  along  the  fissure  zones.  The  vein  usually  contains 
much  gouge  matter  and  also  much  mariposite.  The  quartz  is 
characteristically  ribboned  and  banded,  a  structure  due  to  black 
slaty  seams  disposed  parallel  to  the  walls.  The  lode  or  the  parallel 
series  of  veins  that  may  represent  it  occurs  either  in  the  Mariposa 
beds  or  on  the  contact  between  it  and  the  diabasic  dykes  ("  green- 
stone "  of  the  miners).  In  its  course  it  passes  through  a  great 
variety  of  rocks,  but  it  nevertheless  varies  but  little  in  size    or 


508 


NORTH   AMERICA. 


richness.  The  movements  that  have  resulted  in  the  formation  of 
clay  and  "  pug  "  in  the  lode  have  at  times  been  immense,  since  the 
gouge  in  places  is  30  feet  in  thickness. 

Grass  Valley. — The  Nevada  City  and  Grass  Valley  regions  in 
Nevada  county  may  be  taken  as  furnishing  fairly  typical  Cali- 
fornian  vein  occurrences.  They  were  first  worked  for  their 
placer  gold,  but  as  early  as  January,  1851,  a  stamp-mill  had 
been  erected.  The  districts  are  estimated  to  have  produced 
to  the  end  of  1896  no  less  than  £23,165,000  ($113,000,000) 
gold,  both  from  quartz  veins  and  from  alluvial  deposits.  The 
quartz  veins  lie  along  the  contact  between  the  foothills, 
composed  of  igneous  rocks,  and  the  middle  slopes  of  the  Sierra 
Nevada,  formed  of  sedimentary  rocks — siliceous  argillite,  slate, 
sandstone,  and  schist — partly  of  Jurassic,  partly  of  Carboniferous 


■Sfr/lchtati/icTtQcfi:*  ^-"v/Si,  ■ 


Fig.   163.     Cross-section-  of  Maryland  Vein  above  1,500ft.  level  (Lindgren). 

age.  The  igneous  rocks  are  granodiorite,  diorite,  gabbro,  and 
diabase,  together  with  porphyrite,  pyroxenite,  and  peridotite. 
Amphibolites  have  been  formed  from  the  four  first-named  rocks, 
and  serpentines  from  the  two  last.  The  igneous  rocks  are  Jura- 
Trias  a  or  later,  and  the  eruptive  sequence  was  apparently  closed 
by  the  early  Cretaceous  granodioritic  intrusions.  Fissures  were 
induced  by  folding  and  by  intrusions,  and  these  are  now  filled  with 
vein  matter.  The  principal  vein-stone  is  quartz  with  native  gold 
and  metallic  sulphides,  all  having  been  deposited  in  open  spaces 
along  fissures.  A  remarkable  analogy  in  the  general  character  of 
vein  formation  may  be  traced  between  Grass  Valley  and  Gympie, 
Queensland,  though  in    the    latter    case  auriferous    deposition    is 


"Lindgren,   17th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  II,   1896,  p.  258. 


Plate  XXVI. 


Stope  above  1,500  feet  level.  Maryland  Vein,  Crass  Valley,  California. 


Cavernous  Quartz  Pseudomorphic  after  Original  Barytes  or  Calcite, 
1)e  Lam  ah  .Mine.  Idaho  {Lindgren). 


CALIFORNIA.  509 

obviously  dependent  on  the  presence  or  absence  of  carbonaceous 
matter.  In  this  respect  it  may  be  noted  that  Prichard  a  attributes 
the  origin  of  auriferous  solutions  to  the  intrusion  of  the  granodioritic 
dykes  and  the  actual  precipitation  of  the  gold  of  the  Mother  Lode 
to  the  carbonaceous  matter  of  the  slates  of  the  Mariposa  Formation. 
From  Trinity  county  in  the  north  of  California,  Hershey6 
describes  pockets  of  gold  occurring  mainly  in  a  dirt  seam  at  the 
contact  plane  between  a  massive  diabase  and  an  overlying  Jurassic 
slate.  The  diabase  is  believed  by  him  to  be  the  matrix  of  the  gold, 
since  portions  of  the  rock  on  assay  have  yielded  tenors  of  $2.00 
to  $3.00  per  ton.  It  would,  however,  seem  more  probable  that  the 
gold  had  been  deposited  along  the  plane  of  contact.  The  gold 
grains  of  the  pockets  are  curiously  rounded,  as  if  water- worn. 
They  moreover  occur  near  quartz  veins  that  pass  down  from  the 
slates  into  the  diabase. 

Bodie. — The  Bodie  camp,  Mono  county,  8,200  feet  above  sea- 
level,  is  typical  of  the  mining  fields  situated  in  andesitic  rocks 
on  the  Nevada  border.  In  1875  it  was  the  scene  of  a  great  but 
disappointing  rush  from  Virginia  City,  then  past  the  zenith 
of  its  glory.  The  Bodie  country  is  a  hornblende-andesite,  probably 
overlying  slates  that  are,  however,  not  exposed  within  some 
miles  of  the  field.  The  mines  have  yielded  several  million  dollars 
in  dividends.  The  gold-bearing  quartz  veins  are  confined  to  a 
single  ridge  or  zone  of  country  about  a  mile  long  and  a  quarter  of  a 
mile  wide.  The  veins  carry  equal  amounts  of  gold  and  silver. 
Almost  without  exception  the  lodes  have  failed  to  carry  pay-ore 
to  greater  depths  than  500  feet,  but  a  great  number  of  veins  occur 
and  some  of  these  have  been  of  large  size.  Most  of  them  show  a 
banded  structure.  Manganese  oxides  occur  largely  as  a  filling  in 
vughs.c  The  bullion  is  675  fine  in  gold,  the  remainder  being  silver. 
The  ores  average  about  33  dwts.  gold  and  63  dwts.  silver  per  ton.^ 
The  veins  have  produced  from  1877  to  1907  about  £2,972,500 
($14,500,000).  They  are  usually  termed  gash  veins,  since  their  ores 
disappear  at  comparatively  shallow  depths. 

A  field  apparently  somewhat  similar  to  Bodie  is  the  newly- 
discovered  Hart  region,  in  San  Bernardino  county. 

Placer  Deposits. — The  general  characters  of  the  placer 
deposits  of  California  have  already  been  indicated.  Among  older 
placers,  Lindgrene  describes  an  auriferous  conglomerate  of  Jurassic 

a  Trans.  Amer.  Inst.  M.E.,  XXXIV,  1904,  p.  454. 

b  Amer.  Geol.,  1899,  XXIV,  p.  40. 

c  McLaughlin,  Min.  Sci.  Press,  June  22,  1907,  p.  795. 

d  8th  Ann.  Rep.  State  Min.  Cal.,  18S8,  p.  382. 

e  Amer.  Jour.  Sci.,  XLVIII,  1894,  p.  275. 


510 


NORTH    AMERICA. 


age,  but  his  evidence  for  the  contemporaneous  deposition  of  gold 
and  pebble  is  not  convincing.  R.  L.  Dunn  also  describes  an  auri- 
ferous conglomerate  lying  at  the  base  of  the  Chico  (Cretaceous)  beds 
on  the  Klamath  river,  Siskiyou  county.  It  has  an  average 
thickness  of  100  feet,  the  pay-gravel  being  the  lowest  stratum. 
It  contains  marine  shells  and  is  a  marine  gravel,  though  Dunn 
at  first  believed  it  to  be  of  fluviatile  origin."  The  actual  amount 
recovered  from  the  Cretaceous  auriferous  conglomerate  was 
about  2s.  6d.  (SO. 60)  per  square  foot  of  bed-rock  over  31,000  square 
feet,  while  the  total  value  contained  was  estimated  at  16s.  8d. 
(14.00)  a  ton,  or  4s.  2d.  ($1)  a  square  foot.    There  seems  to  be  no 


3000 


2000t- 


iwmk 


Fig.  164.    Auriferous  gravel  buried  beneath  lava,  Forest  Hill  Divide,  American  River 

(Browne). 
1.  Bed  rock  (metamorphic  slate).     2.  Auriferous  gravel.     3.  Basaltic  lava  cap. 

reason  to  doubt  Dunn's  determination  of  the  source  of  the  contained 
gold,  though  at  the  same  time  he  gives  no  absolute  details  of  the 
condition  of  the  gold,  &c,  merely  remarking  that  it  is  not  water- 
worn.  In  this  connection  it  must  not  be  forgotten  that  if  pyrite 
may  be  deposited,  as  it  frequently  is  in  alluvial  gravels,  gold  may, 
on  decomposition  of  the  pyrite,  be  left  behind,  and  it  is  to  be 
noted  that  the  Siskiyou  deposit  in  particular,  though  very  red  when 
oxidised,  is  blue  at  depth,  denoting  possibly  an  impregnation  with 
pyrite. 

The  Neocene  (Pliocene  and  Miocene)  auriferous  gravels  of 
California  may  be  divided  into  two  main  groups  :  (a)  an  older  and 
more  important,  composed  chiefly  of  white  quartz  pebbles  and 
light-coloured  clays  and  sands  together  with  interbedded  minor 
flows  of  rhyolite,  and  (b)  later  gravels  interbedded  with  andesitic 


a  12th  Ann.  Rep.  State  Min.  Cal.,  1894,  p.  459. 


CALIFORNIA. 


511 


tuffs  and  containing  numerous  volcanic  rock  pebbles.     From  the 
flora  of  the  former  they  are  considered  to  be  Upper  Miocene  in  age. 

Lindgrena  has  described  fully  the  Neocene  rivers  and  the 
conditions  antecedent  to  their  formation.  The  duration  of  the 
volcanic  period  separating  the  two  gravels  is  estimated  at  one- 
twentieth  of  the  period  of  subsequent  denudation.  The  Sierra 
Nevada  in  Neocene  times  is  considered  to  have  formed  a  mountain 
range  as  well  developed  as  that  of  to-day,  and  moreover  one 
situated  in  the  same  position.  The  slope  of  the  Sierra  Nevada  has, 
however,  been  considerably  increased,  and  greater  cutting  power 


Fig.  165.  Plan  of  Blue  Lead,  near  Mokelumne  Hill  (Storms). 

has  thus  been  given  to  its  streams  since  the  deposition  of  the  older 
gravels,  causing  the  latter  to  be  left  as  high-level  gravels  and 
terraces. 

There  are  thus  developed  in  California  two  systems  of  auri- 
ferous river  gravels,  the  courses  of  which  differ  considerably. 
The  modern  river  system  follows  the  courses  of  existing  streams  ; 
the  ancient  river  system  followed  a  general  direction  almost  at 
right-angles  to  that  of  the  present  streams.  The  older  formed 
gravels  that  are  now  partly  eroded  and  partly  covered  by  later  debris 
or  by  thick  lava  flows,  and  as  a  natural  result  of  stream  erosion  and 
base-levelling  the  remnants  of  the  old  valley  gravels  now  occupy 


a  Amer.  Geol.,  1895,  XV,  p.  371 ;   Bull.  Geol.  Soc.  Amer.,  IV,  1893,  p.  257. 


512 


NORTH   AMERICA. 


CALIFORNIA.  513 

a  much  more  elevated  position  than  the  beds  of  modern  streams. 
The  bed-rock  of  an  ancient  valley  has,  at  North  Bloomfield,  an 
elevation  of  2,650  feet  above  sea-level.  At  Yankerville,  near  Forest 
Hill,  placers  are  worked  at  an  elevation  of  2,000  feet.  The  gravels 
contain  fragments  of  nearly  every  rock  known  in  the  Sierras.  The 
chief  auriferous  streams  of  California  are  the  Sacramento  and  San 
Juan  with  their  numerous  westward-flowing  tributaries  that  fall 
from  the  slopes  of  the  Sierra  Nevada.  In  the  old  gravels  the  upper 
portion  is  often  red,  due  to  the  oxidation  of  the  iron  content  ;  the 
lower  is  blue  and  unoxidised.  The  blue  gravels  are  largely  cemented 
with  iron  pyrites.  They  often  contain  silicified  wood.  The  values 
lie  on  the  old  bed-rock.  The  lava-capped  gravels,  as  in  Victoria, 
are  mined  by  shafts,  drifts,  and  levels.  The  North  Bloomfield  mine, 
near  Nevada  City,  is  believed  to  have  been  one  of  the  largest  of 
individual  placer  mines,  covering  1,535  acres.  The  mine  was 
among  the  many  closed  by  the  operations  of  the  Caminetti  Law 
of  1893.     It  had  produced  £1,230,000  ($6,000,000)  gold. 

Oroville. — At  Oroville,  Butte  county,  a  camp  that  may  be 
considered  fairly  typical  of  Californian  dredging  areas,  profitable 
dredging  operations  are  being  carried  on  along  and  beside  the 
Feather  river  over  an  area  of  some  9  miles  long  by  2  miles  wide. 
The  dredging  ground  appears  to  be  worth  8±d.  to  9 id.  per  cubic 
yard  with  an  average  depth  of  33  feet  and  a  maximum  of  some 
60  feet,  at  which  depth  a  "false  bottom"  is  reached.  The  average 
cost  of  dredging  is  about  3d.  per  cubic  yard.  It  is  said  that 
£16,810,000  ($82,000,000)  alluvial  gold  has  been  obtained  within 
a  radius  of  8  miles  of  Oroville/'  The  deposits  are  obviously  the 
debris  from  an  ancient  river  that  flowed  westward  from  the  Sierra 
Nevada.  The  gravel  is  rarely  cemented,  is  fairly  coarse,  and  contains 
no  very  large  boulders.  The  gold  occurs  in  thin  streaks  through 
the  gravel.  It  is  finely  divided  and  nuggets  are  rare.  On  an  average 
the  bullion  contains  922  parts  fine  gold.  Electric  power  is  used 
and  furnishes  cheap  motive  power.  Oroville  presents  in  every 
respect  most  favourable  conditions  for  dredging,  and  to  this 
somewhat  rare  combination  is  entirely  due  the  success  of  the 
industry,  since  it  is  a  form  of  mining  that  is  peculiarly  sensitive 
to  local  conditions. 

The  first  discovery  of  alluvial  gold  in  California  is  credited 
to  J.  A.  Marshall,  who,  on  January  19th,  1848,  found  numerous 
small  grains  of  gold  in  a  mill-race  at  Coloma,  Eldorado  county. 
The  history  of  the  great  gold  rush  that  followed  in  the  succeeding 
year  has  often  been  told  and  need  not  be  recapitulated  in  this  place. 

aKnox,  Trans.  Inst.  Min.  Met..  XII.  1903,  p.  452. 
Ji 


514 


NORTH  AMERICA. 


Turning  to  the  modern  placer  industry,  the  last  available 
returns  show  that  in  1906  California!!  placers  yielded  £1,512,064 
($7,375,925)  and  deep  quartz-mines  £2,328,089  ($11,356,527)  or 
64 '3  per  cent,  of  the  whole.  Placer  operations  are  carried  on  both 
by  hydraulic  mines  and  by  dredging.  The  former  method  is  largely 
practised  in  the  northern  counties  and  more  especially  in  Siskiyou 
and  Trinity,  where  there  are  no  restrictions  as  to  the  disposal  of 
the  debris.  Gold-sluicing  was  formerly  a  flourishing  industry 
throughout  the  foothills  of  California,  but  owing  to  the  stringent 
restrictions  placed  on  the  escape  of  debris  under  the  Caminetti 
Act  of  1893,  the  industry  has  been  almost  completely  destroyed. 
Trinity  county  is  the  most  productive  in  hydraulicing,  Siskiyou 
county  being  second  in  importance.  Drift-mining  is  not  progressing 
in  California,  but  dredging  is  largely  practised  and  is  highly  profitable. 
Butte  county  is  the  largest  gold  producer  in  this  respect,  yielding 
in  1906  nearly  55  per  cent,  of  the  total  amount  recovered  by 
dredging. 

Butte  county  again,  by  virtue  of  its  dredges,  is  the  largest  gold 
producer  in  the  State,  yielding  £6,184,331  ( $29,684,788)  in  1906.  In 
1907  dredges  were  producing  one-fourth  of  the  gold  yield  of  the 
State.  Of  the  total  gold  production  of  California,  estimated  at 
£282,900,000  ($1,380,000,000),  not  more  than  $30,000,000  is  the 
yield  of  the  eastern  Tertiary  propylite  fields/*  By  far  the 
greater  proportion  of  California's  yield  is  due  to  placers,  which, 
to  1900.  furnished  perhaps  as  much  as  94  per  cent,  of  the  whole. 

Marine  Placers. — Sea-beach  placers  are  worked  in  California 
in  a  few  places  in  Humboldt  and  Del  Norte  counties.  Gold  Bluff  in 
the  former  county  is  perhaps  the  best  known.  None  have  proved 
of  great  economic  value. 

The  total  gold  yield  of  California  from  1849  to  1907  is  estimated 
at  :  — 


/  loo. 


Year. 

Value,  Dollars. 

Value,  Sterling. 

1849-1900 

SI. 380,000,000 

£282.900,000  , 

1901 

16,891,400 

3,462,737 

1902 

16,792,100 

3,442,380 

1903 

16,104,500 

3,301,422 

1904 

18,633,676 

3.819.903 

1905 

18,898,545 

3,874.201 

1906 

18.732,452 

3,840,152 

1907 

17,394,863* 

3,565,847* 

$1,503,447,536 

£308,206,642 

*  Estimated  ;    Prel.  Rep.  Director  U.S.  Mint,  Jan.,  1908. 


aLindgren,  Trans.   Amer.   Inst.   M.E.,   XXXIII,   1903,  p.   818. 


515 


IDAHO. 


The  auriferous  region  of  Idaho  lies  in  the  central  and  south- 
western portion  of  the  State.  It  extends  southward  from  45°  45' 
north  latitude  to  near  the  Nevada  frontier,  and  from  the  Oregon 
boundary  line  to  the  114th  meridian  of  west  longitude.  It  may  be 
conveniently  subdivided  into  two  districts,  lying  north  and  south 
respectively  of  the  Snake  river.  In  the  former  district  are  the 
Cretaceous  veins  and  the  Tertiary  placers  of  Oro-Fino,  Florence, 
Warren,  Pierce,  Gibbonsville,  Elk  City,  Idaho  Basin,  and  Hailey. 
South  of  the  Snake  river  the  gold  occurrences  are  restricted  to  Owyhee 
county,  and  are  found  in,  or  arise  from,  veins  of  post-Miocene  age. 
Vein  occurrences  are  of  much  greater  importance  here  than  in  the 
northern  area,  where  the  greater  proportion  of  the  gold  obtained 
has  been  recovered  from  placers. 

The  general  geology  of  the  Idaho  area  is  well  known.  The 
oldest  rocks  are  limestones,  quartzites,  shales,  and  schists,  of  possible 
Carboniferous  age.a  These  lie  as  a  broad  belt  along  the  east  of  the 
region,  and  reach  nearly  as  far  south  as  the  Snake  river.  They  also 
occur  as  a  comparatively  small  area  in  the  north-west.  Between  the 
Carboniferous  exposures  there  has  been  intruded  a  great  central 
belt  of  post-Palgeozoic  and  pre-Miocene  granite  that  apparently 
corresponds  very  closely  in  age  and  general  relations  to  the  great 
granitic  batholiths  of  California.  To  the  west  and  south  are  the 
widespread  Columbia  (Miocene)  basaltic  lava  flows,  that  in  places 
attain  a  thickness  of  2,000  feet.  They  are  associated  with  overlying 
subordinate  rhyolitic  lava-flows.  The  extensive  effusions  of  lava 
considerably  modified  the  drainage  of  the  country,  damming  back 
streams  and  forming  lakes.  Deposits  formed  in  such  lakes  have  a 
considerable  development  in  the  south-west,  along  the  present 
course  of  the  Snake  river.  The  Columbia  lavas  vary  in  character 
from  diabase  to  glassy  basalt.  Numerous  dykes  of  Tertiary  age 
ramify  through  the  granite.  They  range  from  pegmatite  and  aplite 
through  diorite-porphyry  to  basic  minettes  and   lamprophyres. 

Nearly  all  the  veins  north  of  the  Snake  river  are  in  the  granite. 
They  show  a  remarkable  general  uniformity  in  possessing  a  strike 
that  is  either  due  east  and  west  or  very  near  to  that  direction. 
There  is  thus  a  considerable  similarity  to  the  veins  of  the  Butte, 
Montana,  and  to  those  of  the  Blue  Mountains  in  Oregon.  In  the 
latter  region,  however,  the  general  strike  is  rather  north-east  and 
south-west,  but  the  fissures  of  all  three  regions  nevertheless  appear 
to  have  arisen  from  the  same  compressive  forces.  Veins  are 
also  found  north  of  the  Snake  in  granite-porphyry  and  diorite- 
porphyry   intrusive   through   the   granite.      Silver-lead    veins   are 

°  Lindgren,  20th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  Ill,  1900,  p.  75. 


516  NORTH    AMERICA. 

not  uncommon  in  the  sedimentary  rocks,  but  gold-quartz  veins 
are  rare  and  unimportant.  The  gangue  of  the  veins  in  the  granite 
is  ordinarily  quartz  and  valencianite  (orthoclase). 

One  of  the  first  placer  districts  discovered  in  Idaho,  and, 
moreover,  one  of  the  richest,  was  the  Florence,  north  of  the  Salmon 
river.  Its  yield  of  alluvial  gold  from  1861  to  1868  is  estimated  at 
from  £3,000,000  to  £6,000,000  ($15,000,000  to  $30,000,000).  The 
veins  of  the  district  are  low-grade,  with  a  quartz  gangue  free  from 
sulphides.  The  fineness  of  the  vein  gold  is  only  650.  The  country 
is  biotite-granite.  The  Warren  placers  were  also  derived  from 
veins  in  biotite-granite  and  proved,  like  those  of  Florence, 
exceedingly  rich  for  a  few  years  after  their  discovery. 

The  most  noteworthy  districts  north  of  the  Snake  river  lie 
in  the  counties  of  Idaho,  Basin,  and  Boise,  north  and  north-east  of 
Boise  City.  Their  veins  are  either  in  the  post-Palaeozoic  granites, 
or  in  or  with  associated  hornblende-porphyrite  and  minette  dykes. a 
The  granite  country  in  the  immediate  vicinity  of  the  vein  fissure 
suffers  a  marked  change  due  to  the  passage  of  underground  water. 
Biotite  and  hornblende  are  bleached  and  disappear  while  the 
felspars  are  sericitised.  Alteration  is  accompanied  or  followed  by 
pyritous  impregnation.  Both  bench  and  recent  gravels  have  derived 
their  gold  from  these  veins.  The  gravels,  as,  for  example,  those  of 
the  Salmon  river,  were  most  productive  from  1861  to  1870. 

The  Wood  River  district  (Hailey)  is  mainly  a  silver-lead  region,, 
but  a  few  gold-quartz  veins  are  being  worked.  Of  these,  the  Croesus, 
Hope,  and  Camas  are  the  richest.  The  first  lies  entirely  in  quartz- 
diorite,  the  last  in  the  normal  granite  of  Idaho. h 

De  Lamar. — South  of  the  Snake  river,  in  the  Owyhee  range 
in  south-west  Idaho,  is  the  important  Silver  City  and  De  Lamar 
gold  region.  These  camps  are  some  5  miles  apart,  and 
the  principal  veins  are  grouped  between  them,  and  in  their 
immediate  vicinity.  As  with  most  other  gold-quartz  fields  atten- 
tion was  first  attracted  to  the  district  by  the  discovery  of 
placer  gold.  From  1863  to  1869  the  alluvial  gravels  gave 
handsome  returns.  The  first  gold-quartz  veins  worked  were 
those  of  Poorman,  Oro  Fino,  and  War  Eagle,  in  the  granite  east  of 
Silver  City.  It  was  not  till  1871  that  the  present  Black  Jack  and 
Trade  Dollar  veins  were  opened  up  in  rhyolite  on  Florida  Mountain. 
In  1875  the  De  Lamar  veins  were  known,  but  early  workings  on 
them  were  unprofitable,  and  it  was  only  in  1889  that  the  famous 
De  Lamar  ore-shoots  were  exposed.  From  1889  to  1898  the  ore- 
shoots  yielded  £1,183,954  ($5,861,160),  of   which    about    £500,000 

"  Lindgren,  18th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt,  III,  1898,  p.  63S. 
b  Lakes,  Mines,  and  Minerals,  Dec,  1901,  p.  205. 


IDAHO. 


517 


($2,500,000)  was  for  silver  value,  while  the  total  production  of  gold 
from  Owyhee  county,  almost  entirely  derived  from  the  restricted 
area  near  De  Lamar  and  Silver  City,  from  1880  to  1898  inclusive, 
was  313,448  ounces,  valued  at  £1,327,798  (86,477,065)/' 

The  geology  of  the  Owyhee  range  closely  resembles  that  of  the 
northern  area.  A  granite  core  is  almost  completely  covered  by 
Miocene  basaltic  and  rhyolitic  flows,  and  forms  an  igneous  peninsula, 
round  which  thick  Miocene  and  Pliocene  lacustrine  deposits  are 
wrapped.  The  granite  is  of  the  normal  post-Palaeozoic  type.  The 
basalt  is  often  diabasic  in  character.  It  lies  directly  on  the  granite. 
The  rhyolite  is  of  later  date  and  probably  at  one  time  covered  the 
whole  area,  the  subsequent  exposure  of  the  older  rocks  being  due 
to  denudation.      On  Florida  Mountain,   west  of  Silver  City,   the 


'     '    +  +    +  + 

,+  .+  +  +    +  + 

+   +    +    +  +  + 

+  £++  +  +, 

+ ;  +    +  ,  +  +  + 

>   +   +  +  +  i 
V    +   +    +  4-  + 

J  +    +     4-    +  + 

, /+  +  +  +  c 

LA  +  4+  +  +   +\ 

'-  SILVER    CITY      + 
+  /V+-    +    +  0roF.no 

(H  Poorman  a-"Vl        i" 

+V+  +  FJ^rx  4- 


-4-   M'LES 


ScaU 


Fig.  167.     Geology  of  De  Lamar  Mine  and  vicinity,  Idaho  (Schroder  and  Lindgren). 
B.  Basalt.      R.  Rhyolite.      O.  Granite. 


thickness  of  the  rhyolite  flow  is  1,200  feet,  while  on  Cinnabar 
Mountain  it  reaches  2,000  feet.  The  rhyolite  is  of  the  normal  type 
and  was  apparently  extruded  in  thick,  viscous  flows.  Its  colour  is 
grey  to  light-brown.  The  phenocrysts  are  quartz  and  sanidine  (ortho- 
clase),  with  rare  oligoclase.  The  ground  mass  often  shows  flow- 
structure.  Rhyolite  dykes  penetrating  through  the  granite  and 
basalt,  and  indicating  the  original  fissure  vents,  are  common. 
The  final  phase  of  igneous  activity  in  the  area  is  represented  by 
glassy  basaltic  dykes  ramifying  through  the  older  basalts  and 
rhyolites.  The  acid  flows  are  here  described  with  some  particu- 
larity, since  the  gold-quartz  veins  of  De  Lamar  and  Florida  Mountain 


a  Lindgren,  20th  Ann.  Rep.   U.S.  Geol.  Surv.,  Pt.  Ill,  1900,  p.  110. 


518 


yORTH    AMERICA. 


are  by  far  the  most  important  known  in  rhyolite.  It  will,  however, 
be  apparent  from  a  consideration  of  the  features  of  the  Trade 
Dollar  veins  on  Florida  Mountain  that  there  is  probably  no  genetic 
connection  between  the  rhyolite  and  the  gold-quartz  veins,  and 
that  the  occurrence  of  the  latter  in  the  former  is  purely 
adventitious. 

The  De  Lamar  veins  lie  entirely  in  decomposed  rhyolite,  near 
'its  contact  Avith  basalt.  The  rhyolite  is  on  the  whole  greatly 
kaolinised  or  silicified,  and,  especially  near  the  lode  fissures, 
is  highly  impregnated  with  pyrite  and  marcasite.  The  salient 
feature  in  the  De  Lamar  mines  is  the  presence  of  the  so-called 
"  iron  dyke,"  merely  an  intensely  crushed  and  altered  rhyolite, 
highly  impregnated  with  pyrite.  The  chief  mineral-bearing  zone 
lies  in  the  immediate  vicinity  of  the  "  iron  dyke."  The  veins  abut 
against  it  and  are  apparently  cut  off  by  it.     The  De  Lamar  vein 


Fig.  168.     Section  through  De  Lamar  Vein  System  (Lmdgren). 
R.  Rhyolite.      B.  Basalt. 


system  comprises  10  veins  lying  from  20  to  80  feet  apart.  Of  these, 
the  Hamilton  and  the  Seventy  Seven  are  the  richest.  The  width 
of  the  veins  varies  from  1  to  6  feet,  and  will  average  perhaps  3  J  feet. 
The  rich  ore  of  the  De  Lamar  is  contained  in  ore-shoots  that  follow 
approximately  the  dip  of  the  "  iron  dyke."  The  shoots  are  some 
200  feet  in  length,  from  1  to  30  feet  in  thickness,  and  extend  in 
depth  from  near  the  surface  to  the  tenth  level.  The  gangue  is  a 
cavernous  quartz,  largely  made  up  of  thin  intersecting  quartz- 
lamellae  encrusted  with  very  fine  quartz  crystals.  The  whole  is 
obviously  pseudomorphic  after  original  barytes  or  calcite.  The 
gold  is  free,  but  is  very  finely  divided.  The  quartz  carries  0"75 
per  cent,  of  sulphides  (pyrite  and  argentite).  The  impregnated 
country  is  often  rich  in  silver,  but  contains  little  gold.  The  proportion 
of  gold  to  silver  varies  considerably,  and  is  difficult  to  estimate. 
Judging,  however,  from  the  total  output,  the  proportion  of  the 
former  to  the  latter  is  perhaps  1  to  6.  The  average  value  of  the 
ore  treated  at  De  Lamar  and  Florida  Mountain  is  between  £4  and 
£4.  10s.  ($16.00  and  $18.00)  per  ton.« 

"  Min.  Res.  U.S.  Geo!.  Surv.,  1905,  p.  237. 


Plate  XXVII. 


Trade  Dollar  Mine  and  Mill  on  Florida  Mountain,  looking  North-west. 

(U.S.  Geological  Survey.) 


De  Lamar  Mine  and  Mill,  looking  South. 
(U.S.  Geological  Survey.) 


IDAHO. 


519 


On  Florida  Mountain  the  Trade  Dollar  is  the  principal  vein. 
The  value  of  the  ore  lies  at  the  present  time  mainly  in  silver,  which 
occurs  with  gold  in  the  proportion  of  60  to  1.  In  the  early  days 
of  the  mine  gold  predominated  near  the  surface.  The  Trade 
Dollar  vein  was  opened  up  in  rhyolite,  and  has  been  followed 
in  depth  through  the  basalt  into  the  underlying  granite.  On  the 
whole,  it  Avould  appear  to  be  richer  in  the  last  than  in  the  rhyolite 
or  basalt.  The  gangue  filling  is  quartz  and  valencianite  (orthoclase), 
and  is  the  same  in  all  three  rocks. 

The  veins  east  of  Silver  City  (Poorman,  Oro  Fino,  War  Eagle, 
&c.)  are  in  granite.  They  are  in  most  cases  closely  connected  with 
intrusive  dykes,  which  may  be  either  acidic  or  basic.  There  is 
obviously  a  very  close  genetic  connection  between  the  veins  of 
De  Lamar,  Florida  Mountain,  and  War  Eagle.  They  are 
probably  all  to  be  relegated  to  the  same  period,  which  is 
apparently  post-Miocene. 

At  De  Lamar  a  recent  siliceous  spring-deposit  containing 
vegetable  remains  has  been  found  to  yield  small  quantities  of  gold 
and  silver,  one  assay  giving  as  much  as  01  ounce  gold  and  0  25  ounce 
silver." 

As  in  Oregon,  the  Snake  river  in  Idaho  contains  exceedingly 
fine  flour  gold  (4,000  "  colours  "  to  the  grain).  Its  quality  is  high 
(990  fine),  as  indeed  would  follow  from  its  state  of  fine  division. 
A  suction  dredge  to  raise  the  gravels  and  fine  gold  was  successfully 
worked  on  this  river  south  of  Shoshone.  It  treated  3,000  cubic  yards 
of  gravel  per  day,  and  saved,  perhaps,  50  per  cent,  of  the  gold.  The 
average  value  recovered  was  less  than  5d.  (10  cents)  per  cubic  yard.6 

The  total  gold  yield  of  Idaho  is  shown  below  :  — 


Year. 

Value,  Dollars. 

Value,  Sterling. 

To  1900  inclusive 

$112,800,000 

£23,124,000 

1901 

1,869,300 

383,206 

1902 

1,475,000 

302,375 

1903 

1,570,000 

321,850 

1904 

1,710,000 

350,550 

1905 

1,075,600 

220,498 

1906 

1,149,100 

235,566 

1907 

1,087,655* 

222,969 

Grand  total  to  end  of  1907    . . 

§122,736,655 

£25,161,014 

*  Estimated;   Prel.   Rep.   Dir.   U.S.   Mint,  Jan.,   1908. 


"  Lindgren,  loc.  cit.  sup.,  p.   187. 

b  Schultz,  Bull.  U.S.  Geol.  Surv.,  No.  315,  1907,  p.  81. 


520  NORTH  AMERICA. 

NEVADA. 

The  older  rocks  of  Nevada  are  pre-Cambrian  schists  and 
Palaeozoic  and  Mesozoic  sediments.  These  are  intruded  by  por- 
phyry dykes  and  are  often  buried  deep  beneath  Tertiary  andesitic, 
rhyolitic,  and  basaltic  flows.  Intrusive  granitic  batholiths  and 
simple  gold-quartz  veins  of  the  Californian  type  are  rare.  Argenti- 
ferous lead  ores  with  minor  quantities  of  gold  are  not  uncommon 
in  limestones  near  igneous  contacts.  The  deposits  of  the  Eureka 
district  furnish  the  best-known  example  of  this  type.  The  most 
productive  gold  veins  in  Nevada  are,  however,  those  in  later  Tertiary 
propylitic  rocks,  in  which  the  gold  is  generally  subordinate  in 
quantity  to  silver.  Of  this  type  the  famous  Comstock  lode  is  an 
excellent  example.  Of  recent  years  numerous  veins  of  similar 
character  have  been  found  extending  from  the  Comstock  south-east 
along  the  Californian  boundary  to  the  far  south  of  the  State. 
This  chain  of  propylitic  goldfields  includes  Tonopah,  Klondike, 
Goldfield,  Rhyolite,  Bullfrog,  and  several  others  of  present  minor 
importance. 

The  placer  industry  in  Nevada  is  insignificant,  and  is  dwindling 
to  the  vanishing  point.  The  total  yield  for  the  State  for  the  3^ear  1905 
was  only  some  400  ounces,  of  which  three-fourths  came  from  Elko 
county.  In  1906  the  alluvial  gold  recovered  was  greater,  reaching 
2,556  ounces.  Lack  of  water  is  largely  responsible,  but  it  is  also  a 
fact,  as  pointed  out  for  this  particular  region  by  Lindgren,a  that 
rich  propylitic  veins  rarely  produce  important  placer  deposits. 

After  the  partial  exhaustion  of  the  Comstock  and  Eureka 
deposits  in  the  early  'eighties  the  veins  of  Nevada  were  for  long 
neglected,  and  gold-mining  in  that  State  may  be  said  to  have 
revived  only  with  the  discovery  of  the  rich  outcrops  of  Tonopah 
in  1900,  a  discovery  that  led  to  wide-spread  prospecting  and  to 
the  formation  of  the  numerous  camps  of  the  south-west  desert. 
The  ore  from  some  of  these  camps  has  been  phenomenally  rich, 
assaying  often  hundreds  of  pounds  in  gold  and  silver  values  per  ton. 
The  principal  gold-producing  counties  of  Nevada  are,  in  order, 
Esmeralda,  Nye,  Lincoln,  and  Storey. 

Comstock. — The  Comstock  lode  is  perhaps  the  most  widely 
known,  as  it  has  been  the  richest,  of  the  silver-gold  veins  of  modern 
times.  Its  lustre  has,  however,  been  dimmed  for  the  last  25  years, 
and  though  persistent  efforts  have  been  made,  especially  during 
the  last  decade,  to  discover  new  bonanzas  in  the  lode,  these  efforts 
have  as  yet  been  unsuccessful.  Placer  gold  had  been  known  in 
and  had  been  washed  from  the  various  canyons  leading  up  to  the 

a  Trans.  Amer.  Inst.  M.E.,  XXXIII,  1903,  p.  840. 


NEVADA. 


521 


great  lode  as  early  as  1851,  but  the  lode  itself  was  not  demarcated 
until  the  spring  of  1859.  The  term  "gold'  in  connection  with 
these  placer  deposits  is  somewhat  of  a  misnomer,  since  the  bullion 
recovered  in  sluicing  in  Six  Mile  canyon  was  worth  no  more  than 
29s.  ( $7.00)  per  ounce.  In  the  immediate  vicinity  of  the  outcrop  it 
fell  in  value  to  21s.  ($5.00),  being  then  rather  alluvial  silver  than 


.- f 


V-^"//////, 


Cedar  Hill 


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/////////////// 
///////,  S/////4 
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///////////A 


&  tslorcross 

./>^y^ -///////////A 

.Combination  /'///////  /, 

~^-£///jfS //////// 

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b,v     _     y/////////>/J 

HUl  .  ■/--»/ J/////////////, 

GOLD ^N_^TL   _   .J////////////// 

hill _  rn_- T//// //////////// 

jfellowJacker [- -  -Jttltftfft/ittlJI 

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ftfiifif/fKTfTf/Htilttllt/ttlt/Itt 

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Fig.  169.    Geological  Map  of  the  Neighbourhood  of  the  Comstock  Lode  (Modified  from  Becker). 

1.  Hornblende-andesite.     2.  Diorite.  diabase,  and  hornblende-andesite.      3.  Hornblende-mica- 
andesite.      4.  Rhyolite  and  dacite.      5.  Pyroxene-andesite  and  diabase. 


alluvial  gold.  When  the  outcrop  of  the  lode  was  first  worked, 
gold  alone  was  sought,  and  the  presence  of  silver  compounds 
in  quantity  was  not  suspected.  Outcrop  specimens,  however, 
came  into  the  possession  of  Melville  Atwood,  a  Californian 
assayer,  who  determined  a  hitherto  neglected  black  mineral 
staining     the    outcrop    to     be     a     sulphide     of     silver,     and     to 


522  NORTH    AMERICA. 

be  present  in  quantities  denoting  a  value  of  from  £1,000 
to  £2,500  per  ton  of  ore,  thus  making  the  Comstock  the 
greatest  silver  deposit  that  had  been  known  since  the  days 
of  Potosi.  The  famous  ;  Washoe  rush  '  was  immediately 
precipitated,  and  the  towns  of  Virginia  City,  Gold  Hill,  and  Silver 
City  sprang  up  Avith  mushroom-like  growth  along  the  line  of  the 
lode.  The  first-named  city  had,  at  one  time,  a  population  of  35,000 
inhabitants.  For  the  next  decade,  despite  the  terrible  stress  of  the 
intervening  years  of  the  Civil  War,  the  Comstock  was  the  most 
prosperous  mining  field  in  the  world.  Before  1880  no  less  than 
£23,753,500  ($115,871,000)  had  been  paid  in  dividends.  From  the 
year  of  its  discovery  to  the  end  of  1906  its  total  production  may  be 
estimated  at  £76,731,295  ($374,299,000),  of  which  the  value  of  the 
gold  produced  is  responsible  for  £30,750,000  ($150,000,000).  The 
difficulties  encountered,  both  in  metallurgical  and  mining  practice, 
were  enormous.  The  former  were  surmounted  by  the  evolution 
of  the  Washoe  process  of  hot-pan  amalgamation.  The  latter  were 
more  serious,  and  have  not  yet  been  completely  overcome.  The 
roofs  and  walls  of  the  large  cavities  made  in  mining  required 
adequate  support,  a  difficulty  solved  by  the  adoption  of  the  then 
novel  method  of  "  square-set  '  timbering.  Enormous  quantities 
of  water  had  to  be  pumped  to  the  surface,  necessitating  costly 
pumping  machinery.  The  heat  encountered  in  the  deeper  levels 
proved  a  most  serious  and,  finally,  an  insurmountable  obstacle. 
The  great  streams  of  water  gushing  from  the  fissures  in  the  rock 
possessed  a  temperature  generally  over  110°  Fahr.  In  the  case  of 
the  Yellow  Jacket  shaft,  a  stream  was  encountered  with  a  tem- 
perature of  170°  Fahr.  The  heat  is  probably  to  be  attributed  to 
expiring  vulcanicity,  since  the  well-known  solfataric  Steamboat 
Springs  lie  only  some  10  miles  to  the  north-north-west.  Even  at 
so  shallow  a  depth  as  1,500  feet  it  was  necessary  to  pump  cold 
water  into  the  working  faces  in  the  endeavour  to  reduce  the 
temperature.  The  miners,  stripped  to  the  waist,  could  work  only 
15-minute  spells,  and  the  effective  working  time  of  each  miner 
during  a  nominal  shift  of  eight  hours  was  only  two  hours.  Mining 
costs  were  therefore  enormous.  To  secure  better  ventilation,  and  to 
reduce  the  great  expense  of  pumping  water  to  the  surface  at  the 
outcrop  of  the  lode,  the  Sutro  adit  level,  20,000  feet  long,  was 
driven  to  strike  the  lode  1,600  feet  below  the  average  level  of 
its  outcrop.  Its  progress  was  unfortunately  so  slow  that  many 
of  the  bonanzas  above  the  tunnel  level  had  been  worked  out 
before  the  tunnel  reached  the  lode.  The  Sutro  adit  nevertheless 
proved  of  vital  importance  during  later  operations.  The  fight 
against  heat  and  water  was  vigorously  continued  until  1883, 
when    the    great    depth,    considering  the  conditions,  of  3,300  feet 


NEVADA. 


523 


from  the  surface  had  been  reached.  By  1887  most  of  the  mines 
had  been  shut  down.  The  field  remained  almost  deserted  until 
an  association  of  the  28  existing  mines  was  formed  in  1898  to 
unwater  the  old  workings.  This  end  has  partly  been  effected, 
though  the  water  being  pumped  has  a  temperature  of  160°  Fahr., 
and  is  slightly  acid.  No  new  bonanzas  have  as  yet  been 
discovered,  and  the  work  is  being  carried  on  entirely  by  contributed 


Foot  wall 


Dioritc 


Fig.  170.    Showing  formation  of  Bonanzas  in  Hanging-wall  of  Comstock  Lode  (Rtid). 


capital.     Pumping,   mining,   and  milling  operations  are  performed 
by  electricity  generated  at  the  Truckee  river,  33  miles  from  Virginia 

City.« 

The  Comstock  lode  lies  on  the  east  flank  of  Mount  Davidson 
(7,941  feet),  an  elevation  on  a  spur  of  the  Sierra  Nevada.  The 
strike  of  the  lode  is  nearly  north  and  south,  and  it  has  a  total  length 
of  some  2 h  miles.  At  both  the  northern  and  southern  ends  it  forks 
into  two  small  branches  which  soon  thin  away  in  the  country.  The 
thickness  of  the  lode  varies  from  100  to  1,400  feet.  The  footwall 
is  always  distinct  and  well-defined,  while  the  hanging-wall  is  rarely 
clearly  marked,  the  ore  blending  with  the  country.  The  true  dip 
of  the  lode  is  to  the  east.    The  vein  matter  is  quartz,  but  brecciated 


a  Ross,  Min.  Sci.  Press,  Oct.  12,  1907,  p.  468. 


524  NORTH    AMERICA. 

masses  of  country,,  often  of  high  grade,  are  scattered  through 
the  lode.  The  ores  are  silver  sulphides  (argentite,  stephanite, 
polybasite)  with  occasional  galena  and  zinc.  The  bullion  derived 
from  the  ores  contained  half  its  value,  or  6  to  7  per  cent,  by  weight, 
in  gold.  The  ore  occurs  entirely  in  shoots  or  bonanzas  separated  by 
wide  barren  stretches.  Recent  work  outlined  by  Reida  has  thrown 
considerable  light  on  the  origin  of  the  bonanzas  of  the  central  and 
northern  Comstock.  Near  Virginia  City  the  bonanza-ore  occurs 
not  in  the  main  fissure  but  in  nearly  vertical  fissure  planes  in  the 
hanging-wall.  These  vertical  veins,  since  they  pinch  out  in  height, 
are  believed  to  arise  from  relief  from  tension  in  the  hanging-wall, 
the  tension  being  due  to  a  differential  movement  (amounting  to 
3,000  feet)  of  the  walls  of  the  main  fissure.  The  apparent  splitting 
of  the  lode  at  the  surface  is  explained  in  the  same  way,  the  rich 
east  vein  found  there  being  a  vertical  that  had  reached  the 
surface,  probably  merely  by  the  erosion  of  the  overlying  rock. 
As  will  readily  be  seen  on  reference  to  the  accompanying  sketch, 
the  east  vein  (1),  the  great  bonanza  (2),  and  the  lowest  vein 
(3)  now  being  worked,  have  all  therefore  a  common  origin.  On 
the  other  hand,  the  bonanzas  of  Gold  Hill  further  south  are  of 
an  entirely  different  character,  and  lie  within  the  main  fissure 
itself.  Assays  of  the  waters  of  the  Comstock  lode  gave  the 
following  remarkable  results  : — & 


Gold 
Silver 


Vadose  Waters. 


4-1528 
188  0912 


Deep  Waters. 


'298  mgm.  per  ton  of  solution. 
2-920      „ 


The  waters  carry  alkaline  sulphates  and  carbonates.  Sulphates 
(mainly  ferrous)  are  now  being  plentifully  deposited  in  unused 
levels.  Numerous  faults  occur  in  the  region  and  these  are  shown  by 
Reid  to  have  vitally  affected  the  length  of  the  main  fissure,  and 
to  be  responsible  for  many  of  the  orographic  features  of  the  district. 
Cedar  Ravine,  Ophir  Ravine,  and  Bullion  Ravine  are  thus  the 
physiographic  expressions  of  fault-planes.  The  Comstock  lode 
itself  lies  along  a  great  fault,  the  eastern  member  of  the  block- 
faulting  system  of  Mount  Davidson. 

The  petrological  nomenclature  of  the  rocks  adjacent  to  the  Com- 
stock  lode  raises  a  much-vexed  question.  The  monumental  work 
of  Dr.  Becker  in  1882  gave  rise  to  a  vigorous  controversy  that  has 
done  much  to  advance  petrological  science.     Lapse  of  time  and 

"  Bull.  Geol.  Univ.  California,  IV,  1905,  p.   178. 
"  Reid,  loc.  cit.  sup. 


NEVADA.  525 

the  progress  of  petrology  have  served  to  diminish  rather  than  to 
accentuate  the  differences  between  Dr.  Becker's  nomenclature 
and  that  proposed  by  Messrs.  Hague  and  Iddings.  It  will  serve 
no  useful  purpose  to  recapitulate  in  this  place  the  points  at  issue. 
They  may  be  followed  by  reference  to  the  literature. a 

The  oldest  igneous  rocks  of  the  district  may  be  regarded  as 
pyroxenic  (augite-hypersthene)  and  hornblendic  andesites.  The 
former  are  probably  the  older  and  shade  away  by  differences  of 
crystallization  to  diabase  and  augite-diorite.  In  places  the  horn- 
blende-andesite  is  known  to  be  intrusive  into  the  pyroxenic  forms, 
but  the  general  relations  are  not  at  all  clear.  After  a  temporary 
cessation  of  volcanic  activity  the  older  andesites  were  intruded  by 
hornblende-mica-andesites,  dacites,  rhyolites,  and  basalts.  Glassy 
forms  are  found  only  on  or  near  the  surface,  while  rocks  from  depths 
are  generally  holocrystalline.  All  are  probably  Tertiary  in  age. 
The  Comstock  lode  therefore  lies  wholly  within  a  rock  that  may 
shade  from  the  augite-diorite  of  Mount  Davidson  on  the  west  to 
undoubted  andesite  on  the  east.  A  remarkable  rock  is  the  "black 
dyke,"  a  diabase  dj^ke  on  the  footwall  of  the  lode. 

The  pyrite  and  also  the  augite  of  the  country  adjacent  to  the 
lode  was  found,  on  assay  by  J.  H.  Curtis,  to  be  slightly  auriferous, 
the  pyrite  yielding  as  much  as  •  30  gramme  gold  per  metric  ton. 

Fairview  and  Wonder. — South-east  of  Carson  Sink,  in 
Churchill  county,  are  the  newly  established  camps  of  Wonder  and 
Fairview.  The  principal  rock  of  the  latter  field  is  andesite,  which 
is  intruded  by  later  andesitic  and  rhyolitic  dykes.  In  the  main 
ore-zones  the  gangue  is  quartz,  but  the  country  adjacent  to  fissure 
zones  has  also  been  extensively  silicified.  The  valuable  minerals 
are  free  gold,  cerargyrite,  and  argentite.  Ruby  silver  and  silver 
bromide  are  also  found.  About  one-fifth  of  the  value  of  the  ore 
is  due  to  gold.^  Wonder  is  18  miles  north  of  Fairview.  Here  also 
are  two  generations  of  andesite,  in  the  older  of  which,  as  at  Tonopah, 
a  field  to  be  described  later,  the  ore-bodies  have  been  deposited. 
Later  rhyolite  dykes  cut  through  the  andesite,  and  it  is  along 
contacts  of  the  latter  with  rhyolite  hanging-walls  that  the  richer 
ore-shoots  lie.  Gold  may  also  be  found  in  silicified  zones  in  ande- 
site. The  proportion  in  value  of  gold  to  silver  in  the  ore  is  from 
1  :  4  to  1  :  8.  Silver  sulphides,  taken  often  from  the  outcrop  itself, 
furnish  the  bulk  of  the  rich  ore.c 

aKing,  U.S.  Geol.  Surv.,  Expl.  40th  Parallel,  III,  "  Mining  Industry,"  1870; 
Church,  "The  Comstock  Lode,"  New  York,  1879;  Becker,  Mon.  U.S.  Geol.  Surv.,  Ill, 
1882  ;  Hague  and  Iddings,  Bull.  U.S.  Geol.  Surv.,  No.  17,  1885  ;  Becker,  Bull.  Cal. 
Acad.  Sci.,  No.  6,  1886  ;  Id.,  Amer.  Jour.  Sci.,  II,  XXXIII,  1887,  p.  50  ;  Reid,  loc. 
cit.  sup. 

6  Zalinski,  Eng.  Min.  Jour.,  April  13,  1907. 

c  Id.,  ib.,  April  20,  1907. 


526  NORTH    AMERICA. 

Manhattan. — Manhattan  is  likewise  a  new  camp,  its  existence 
dating  back  no  further  than  April,  1905.  It  lies  30  miles  north- 
north-east  of  Tonopah  at  an  elevation  of  some  7,250  feet  above 
sea-level.  The  sedimentary  rocks  of  the  region  are  highly  metamor- 
phosed (presumably  Palaeozoic)  slates,  limestones,  and  quartzites. 
The  predominant  members  were  originally  slates  that  now  appear  as 
glossy  phyllites  or  as  biotite-schists.  The  schistosity  is  parallel  with 
the  bedding  planes.  Granite  is  found  intrusive  in  the  neighbourhood, 
and  is  probably  partly  responsible  for  the  metamorphism  noted. 
Diorite-porphyry  of  unknown  relations  also  occurs.  Tertiary  rhyolite 
covers  much  of  the  sedimentary  strata,  through  which  it  is  also 
found  intrusive.  The  rhyolitic  flows  are  in  places  hundreds  of  feet 
in  thickness.  Ore-deposits  at  Manhattan  are  confined  entirely  to 
the  metamorphosed  sedimentaries."  The  ore-bodies  are  :  (a) 
narrow,  tabular  veins  crossing  the  bedding  and  schistosity  of  the 
met  amorphic  rocks  ;  (b)  deposits  interlaminated  with  the  schistosity  ; 
and  (c)  deposits  parallel  to  the  bedding  planes  and  forming  siliceous 
replacements  in  limestones  and  other  calcareous  beds.  The  principal 
gangue  materials  are  quartz  and  calcite,  but  barytes  and  fluorite 
are  sometimes  present.  The  value  of  the  lode  lies  almost  entirely 
in  its  gold,  which  is  finely  disseminated  through  the  quartz.  Low- 
grade  ore  occurs  in  brecciated  zones  cemented  by  quartz.  Out- 
crop ores  are  rich,  ranging  in  value  from  £14  ($70.00)  to  £60 
($300.00)  per  ton,  with  an  average  value  of  £25  ($125). 

Rawhide. — One  of  the  most  recently  discovered  of  the  new 
gold  camps  of  Nevada  is  Rawhide,  in  Esmeralda  county.  It  was 
located  early  in  1907  and  was  the  objective  of  a  vigorous  rush 
towards  the  end  of  that  year.  The  country  appears  to  show  con- 
siderable geological  affinity  with  Tonopah.  It  is  a  brecciated 
quartz-porphyry,  originally,  perhaps,  an  andesite-breccia,  which 
has  been  so  altered  as  now  to  be  difficult  of  identification.6  The 
ore  may  be  quartz,  quartz-porphyry,  silicified  rhyolite,  or  kaolinised 
porphyry. 

Tonopah. — The  mining  field  of  Tonopah  lies  in  the  west  of 
Nevada  and  of  the  Great  Basin  region,  near  the  boundary  of 
Esmeralda  and  Nye  counties.  Its  lodes  were  discovered  only  in 
1900,  as  a  result  of  assays  of  outcrop  specimens  collected  by 
a  wandering  prospector.  Outside  a  limited  area  in  the  immediate 
vicinity  of  the  claims  marked  off  by  the  original  discoverer  no 
further  valuable  lodes  have  been  found.     The  geology  of  the  dis- 

a  Emmons,  W.  H.,  and  Garrey,  Bull.  U.S.  Geol.  Surv.,  No.  303.  1907,  p.  84. 
h  Del  Mar,  Algernon,  Eng.  Min.  Jour.,  April  25,  1908,  p.  853. 


NEVADA. 


:>2- 


trict  has  been  fully  described  by  Spurr  in  a  monograph"  that 
may  well  serve  as  a  model  for  future  descriptions  of  andesitic 
goldfields. 

No   ancient   sedimentary  rocks   occur    nearer   Tonopah    than 
some  eight  miles  to  the  south,  where  limestone  of  probable  Cambrian 


Fouits 


Veins  _ . 


Scale 


Fig.  171.     Geological  Map  or  Tonopah  Goldfield  (Spurr). 

1 .  Earlier  Andesite.  2.  Later  Andesite.  3.  Heller  Dacite.  i.  Fraction  Dacite-breecia.  5.  Tono- 
pah rhyolite-dacite.  6.  Siebert  tuffs  (lake  beds).  7.  Oddie  rhyolite.  8.  Brougher  dacite.  9.  Latest 
rhyolite  or  dacite. 


or  Silurian  age  is  found.  The  volcanic  breccias  of  Tonopah,  never- 
theless, contain  occasional  fragments  of  limestone,  quartzite,  and 
granite,  that  have  probably  been  derived  from  underlying  rocks. 


Prof.  Paper,  U.S.  Geol.  Surv.,  No.  42,  1905. 


NORTH    AMERICA. 


The  oldest  igneous  rock  is  a  somewhat  porphyritic,  always  decom- 
posed andesite,  that  is  assumed  to  have  been,  when  fresh,  a 
hornblende-biotite-andesite.  In  this  rock  all  the  important  silver- 
gold  veins  are  found.  Its  surface  area  is  small,  but  it  has  been 
proved  to  occur  extensively  under  later  lavas.  A  second  period 
of  volcanic  activity  produced  also  an  andesite  (biotite-augite-), 
but  one  much   less   siliceous  and  normally   much  less  decomposed 


r#»  u  ^  ^  <fl 


f**>«f 


^  *  ♦  .,  -  //  *  -"* 


North  Star  shaft 


0 


^oo 


Scale 

400  600 


600 


ioqo  feet 


Fig.  172.     Section  showing  masking  of  Auriferous  Veins,  Toxopah  (Spun-). 

than  the  first-described.  Possessing  more  iron  it  is  usually  darker, 
and  when  decomposed,  more  highly  coloured  than  the  underlying 
andesite. 

Rhyolite  and  dacite  flows,  genetically  very  closely  connected, 
succeeded  the  andesites.  The  dacite  is  highly  siliceous  and 
might  well  be  classed  as  a  rhyolite.  The  term,  however,  serves  to 
clearly  distinguish  it  from  an  exceedingly  acid  rhyolite  found 
elsewhere  in  the  district.  These  rhyolite-dacites  have  been  sub- 
divided and  locally  named  according  to  character  and  to  relative 
position.  They  were  poured  out  as  flows,  between  the  periods  of 
the  extrusion  of  which  were  periods  of  explosive  eruption  now  repre- 
sented by  interbedded   tuff.       The  Brougher  dacite,  resisting  well 


NEVADA. 


529 


the  somewhat  weak  weathering  agents  of  the  region,  forms  most 
of  the  hills  of  the  district.  The  highly  siliceous  (Oddie)  rhyolite, 
above  mentioned,  lies  to  the  north  of  Tonopah  and  makes  up 
the  bulk  of  Mount  Oddie.  The  contemporaneous  Siebert  tuffs  are 
stratified  and  are  obviously  of  lacustrine  origin.  The  last  lava 
flows  of  the  region  appear  to  have  been  basaltic  in  character, 
though  certain  rhyolite  and  dacite  volcanic  necks  indicate  craters 
and  vent -filling  somewhat  later  in  age. 

Owing  to  extensive  faulting  the  structure  of  the  district  is 
extremely  complicated.  As  already  observed,  the  most  important 
mineral  veins  are    restricted  to  the  earlier  andesite.     They  were 


m 


m   m   EHi   ra   n 


DZl 


ra 


Hypothet- 
ical deep- 
seated 
granite. 


Hypothet-  Earlier            Later             Dacite        Tonopah      Lake  beds.        Faults 

ical  deep-  andesite.       andesite.          breccia.       rhyolite- 

seated  dacite. 
limestone. 


Later  da- 
cite and 
rhyolite 

intru- 
sions. 


Fig.  173.    Ideal  Section  across  Tonopah  Rocks    (Spurr). 


Earlier  ande- 
site veins 
(lesser  veins 
belonging  to 
other  periods 
not  repre- 
sented). 


formed  prior  to  the  deposition  of  the  later  rocks,  and  are  due  to 
replacement  and  silicification  of  the  andesite  along  fractures.  The 
direction  and  position  of  the  ore-shoots  within  the  fissure-zones  is 
largely  affected  by  the  cross-fractures,  since  the  latter  have  deter- 
mined, during  the  period  of  active  ore-deposition,  the  local  direction 
of  the  flow  of  the  hot,  ascending,  ore-bearing  solutions.  The  gangue 
of  the  primary  ores  is  quartz  intercrystallized  with  adularia  (ortho- 
clase),  together  with  minor  sericite  and  carbonates.  Both  quartz 
and  adularia  have  obviously  been  deposited  from  solution.  The 
ores  are  silver  sulphides  (polybasite,  argentite,  and  stephanite), 
selenide  of  silver  (?),  chalcopyrite,  pyrite,  galena,  and  blende.  In 
an  average  ore,  gold  is  present  in  the  proportion  by  weight  of  1  to 


Kl 


530  NORTH   AMERICA. 

100.  Free  gold  has  never  been  detected  in  the  sulphide  ores  but 
naturally  it  occurs  to  some  extent  in  the  upper  oxidised  zones. 
In  some  places  the  oxidised  ores  are  found  as  deep  as  700  feet,  a 
feature  perhaps  not  remarkable  in  view  of  the  aridity  of  the  region, 
and  of  the  fact  that  certain  shafts  are  dry  at  depths  of  over  1,000 
feet.  Water,  though  in  no  great  quantity,  has,  however,  been 
struck  in  other  shafts  at  much  less  depth.  Where  the  old  vein- 
outcrops  lie  buried  beneath  later  lavas  their  zones  of  oxidation 
may  be  comparatively  shallow  (200  feet).  Silver  chloride  is 
abundant  in  the  oxidised  ores.  The  presence  of  selenium,  which 
is  revealed  only  by  analysis,  furnishes  an  interesting  analogy  with 
the  geologically  somewhat  similar  fields  of  Waihi,  New  Zealand, 
and  of  Redjang  Lebong,  Sumatra. 

Numerous  poor  or  almost  barren  silver-gold  quartz  veins 
occur  in  the  Tonopah  rhyolite-dacite,  and  also  in  calcitic  gangue  in 
siliceous  rhyolites,  as  at  Mount  Ararat.  The  ores  contained  in 
these  veins  probably  arise  from  the  solution  and  re-deposition  of 
the  ores  of  the  earlier  andesites.  Spurr  draws  attention  to  the 
analogies  presented  by  this  field  in  respect  of  its  geology  and  ore- 
deposition  with  those  of  Washoe  and  Eureka,  Nevada,  and  of 
De  Lamar  and  Silver  City,  Idaho. 

The  Tonopah  veins  vary  in  width  from  a  few  feet  to  40  feet. 
In  some  mines  ore-shoots  have  been  developed  for  1,000  feet  along 
the  strike.  In  1906  working  costs  were  so  high  that  nothing  below 
£6  ($30.00)  per  ton  was  treated.  To  that  year  the  total  output  of 
the  Tonopah  camp  had  been  £2,665,000  ($13,000,000).  The  yield 
for  the  year  1906  was  £267,458  ($1,304,677)  in  gold  and  £782,610 
($3,817,612)  in  silver. 

Ten  miles  south  of  Tonopah  is  the  Southern  Klondike  district. 
As  at  Manhattan,  Palaeozoic  sedimentary  rock  (in  this  case, 
limestone)  intruded  by  a  granitic  dyke,  is  surrounded  at  the 
surface  by  Tertiary  lava  flows.  The  main  ore-body  is,  however, 
somewhat  remarkably  situated.  It  is  a  quartz  vein  carrying  silver 
and  gold,  and  lies  in  the  limestone  parallel  to  the  granitic  dyke 
mentioned  above  and  75  feet  to  the  south-east  of  it.  The 
occurrence  is  described  by  Spurr, a  who  compares  the  acid  intrusion 
with  the  beresite  of  Berezovsk  in  the  Urals.  With  the  silver  and 
gold  are  associated  galena  and  pyrite  and  possibly  stetfeldtite 
(copper-antimony-silver  sulphide).  The  outcrop  ores  were  very 
rich. 

Goldfield. — By  far  the  most  important  camp  in  south- 
western Nevada  at  the  present  time  is  Goldfield.  Active  mining 
operations  on  this  camp  were  commenced  only  in  1903,  though  the 

a  Econ.  Geol.,  I,  1906,  p.  382. 


H 

« 

O 

PH 
W 

H 
S 

o 

tf 

CO 

iJ 
iJ 

X 

w 
«! 

P4 
o 

o 
H 


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O 


8 

o 


> 


£    0Q 


o 
o 
h1 

q" 
o 
o 

s 


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o 

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o 

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CO 


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a 
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o 

o 

H 


NEVADA. 


531 


field  had  been  prospected  in  the  previous  year.  So  rich  was  some  of 
the  surface  ore  that  it  was  found  necessary  when  blasting  to  cover 
the  hillside  with  bullhides  to  prevent  unnecessary  loss.a  For  1906 
the  yield  of  Goldfield  was  £1,440,361   ($7,026,154)  in  gold,   and 


[itiOTiieter 


-  -    -  - 


'.'.'.•' 

,   :iy,- 
.   A  --.v.  t 

;~, \rr^rrt  7TTT  V  v  *.  v  - 


-  OllTln^baMlL.           Rbrollfe.            6leh*rt  luffa        Quarts  hoMll.    Volranlcbriwl*.    Qoartzlatit*. 
<  Flows  and         .  Loli i  nova.)         (Lake  beds  i  -.1 (Roupbly  bed-       (Flows  with 


And  .-Kit*?.  Khvollle. 

(UWr  flows  (Earllrr  flow 

&nd  intra  with  lntru«1*e 

si  oris.}  niB«in  md 

luOa.) 


An.|i-Ml«. 
(Earlier 
flow*.) 


Alaaklu-. 
(Inlru»i*e  tn 
Paleoiolc  aed- 

Imanu.) 


-— J;m>-siix. 


Fig.  174.  Geological  Map  of  Goldfield,  Nevada  (Ransome). 

only  £2,149  ($10,484)  in  silver.     Owing  to  the  importance  of  the 
camp  its  geological  literature  is  already  extensive.5 


aMin.  Sci.   Press,  June  8,  1907- 

&Spurr,  Bull.  U.S.  Geol.  Surv.,  No.  225,  1904,  p.  118;  Id.,  ib.,  No.  260,  1905, 
p.  132  ;  Hastings  and  Berkey,  Bull.  Amer.  Inst.  M.E.,  No.  8,  March,  1906 ;  Ransome, 
Bull.  U.S.  Geol.  Surv.,  No.  303,  1907,  p.  7  ;  Rickard,  T.  A.,  Min.  Sci.  Press,  May  30,  1908. 


532  NORTH    AMERICA. 

Goldfield  lies  on  an  elevated  plateau,  5,700  feet  above  sea- 
level,  and  near  the  so-called  river  Amargosa,  the  only  running  water 
within  40  miles  of  the  town.  The  Palaeozoic  basement  rocks  of  the 
district  have  been  exposed  by  denudation  in  a  few  places,  as  on 
Columbia  and  Vindicator  Mountains.  Where  exposed,  they  are 
contorted  and  metamorphosed  jasperoid  and  vitreous  quartzites, 
representing  original  calcareous  shales,  limestones,  and  quartzites, 
the  carbonate  of  lime  of  the  former  being  now  largely  replaced 
by  silica.  Metamorphism  is  apparently  due  to  post-Jurassic  acid 
intrusions  of  the  rock  type  termed  by  Spurra  "  alaskite  "  (a  dyke- 
rock  composed  of  quartz  and  minor  orthoclase).  Most  of  the 
alaskite  in  the  Goldfield  area  contains  in  addition  to  quartz  and 
orthoclase  a  little  biotite  and  plagioclase.  These  older  rocks  are 
covered  by  thick  Tertiary  volcanic  deposits  of  varying  type  and 
composition.  Their  sequence  may  be  succinctly  shown  by  the 
following  tabled  in  which  the  older  rocks  are  shown  at  the 
bottom  :  — 

12.  Olivine  basalt ;    flow  and  small  intrusive  bodies. 

11.  Breccia  and  conglomerate. 

10.  Rhyolite;  flow. 

9.  Lake  beds ;    tuffs. 

8.  Quartz-bearing  basalt ;   flow  intercalated  in  lake  sediments. 

7.  Lake  beds  ;   tuffs,  possibly  corresponding  to  Siebert  tuffs,  Tonopah. 

6.  Latite  and  rhyolite  ;   flows. 

5.  Dacite  ;   sheet-like  and  irregular  intrusion,  possibly  in  part  a  flow. 

4.  Andesite  ;    flows  with  some  tuffs  and  small  intrusive  bodies. 

3.  Rhyolite  ;    intrusive  masses. 

2.  Rhyolite  ;   flows  and  tuffs. 

1.  Andesite ;  flow. 

The  most  important  rock  of  the  district,  from  an  economic 
point  of  view,  is  a  dacite,  No.  5  in  the  above  list,  and  the  country 
of  all  the  richer  veins.  It  resembles  the  underlying  andesites  in 
appearance,  but  is  perhaps  somewhat  more  porphyritic.  Unlike 
them,  however,  it  contains  phenocrysts  of  quartz,  and  the  rock  is,  as 
a  whole,  made  up  of  labradorite,  augite,  hornblende,  biotite,  and 
quartz,  with  the  usual  andesitic  ground  mass.  Chemical  analysis 
shows  it  to  contain  60  per  cent,  of  silica.  The  Tertiary  lavas,  when 
considered  broadly,  have  a  gentle  quaquaversal  dip,  and  the  general 
structure  of  the  district  is  that  of  a  geological  dome  in  which  the 
younger  formations  dip  away  from  a  pre-Tertiary  core  exposed  by 
denudation. 

The  valuable  portion  of  the  Goldfield  deposits  is  an  oxidised 
gold-ore,  derived  from  original  sulphide  ores  containing,  in  addition 

aAmer.    Geol.,    XXV,    1900,   p.  229. 
"  Ransome,  loc.  cit.  sup.,  p.  14. 


NEVADA.  533 

to  gold,  unimportant  quantities  of  silver,  copper,  antimony,  arsenic, 
bismuth,  and  tellurium.  The  deposits  have  been  formed  along 
fissure  zones,  and  their  formation  has  been  attended  by  much 
silicification  and  impregnation  of  the  vein-walls.  The  ore-zones, 
though  not  necessarily  their  richer  portions,  often,  therefore,  stand 
well  above  the  level  of  the  adjacent,  more  easily  eroded  rock.  The 
ore-zones  of  Goldfield  are  extremely  irregular  in  form  and  are 
equalled  in  this  respect  only  by  the  irregularity  of  the  pay-shoots 
or  richer  bonanzas  occurring  within  them.  The  gangue  is  ordinarily 
a  dense  flinty  quartz  resulting  from  silicification  along  shattered 
fracture-zones  in  the  dacite.  The  unoxidised  ore  of  the  district 
consists  of  pyrite,  bismuthinite,  and  probable  tetrahedrite.  Free 
gold  is  often  seen  with  the  sulphides.  The  latter  occur  as  crusts, 
and  also  in  a  finely  divided  state  well  disseminated  through  the 
gangue.  Concentric  shells  of  sulphides  about  silicified  rock  frag- 
ments are  common  in  the  richer  shoots,  quartz  with  free  gold  often 
forming  the  innermost  shell,  thus  recalling  the  method  of  ore- 
deposition  in  the  Bassick  volcanic  vent,  Custer  county,  Colorado. 
The  order  of  deposition  may,  however,  vary,  and  the  gold  may  be 
deposited  on  the  outside  of  the  sulphides.  Minute  quantities  of 
tellurium  have  been  detected  on  analysis.  The  ore  treated  has 
hitherto  been  of  very  high  grade,  often  averaging  £100  ($500)  per  ton 
over  many  thousands  of  tons.  Though  much  of  the  very  rich  ore 
has  been  oxidised,  yet  some,  at  least,  of  the  sulphide-ore  has 
exceeded  in  value  anything  found  in  the  upper  zone. 

The  field  is  much  better  situated  with  respect  to  a  water  supply 
than  Tonopah,  since  most  shafts  are  wet  at  depths  below  200  to 
250  feet.  Power  for  the  mines  is  obtained  from  electricity  generated 
at  Bishop's  Creek,  California,  98  miles  to  the  south-west.  Goldfield 
is  at  the  present  time  the  richest  camp  in  Nevada,  having  in  1906 
produced  45  per  cent,  of  the  total  gold  yield  of  the  State,  and  a 
similarly  high  percentage  in  1907. 

Rhyolitc. — The  Rhyolite  or  Bullfrog  district  is  situated  about 
60  miles  south-east  of  Goldfield.  The  two  main  camps,  Rhyolite 
and  Bullfrog,  were  formed  about  1904.  On  this  field  the  basement 
rocks  are  pre-Silurian  quartz-,  quartz-muscovite-,  and  amphibole- 
schist,  gneiss,  and  crystalline  limestone.  Through  the  metamorphic 
rocks  numerous  pegmatitic  veins  are  intruded.  The  whole  series  is 
overlain  by  Silurian  limestones.  None  of  these  are  however  of 
economic  importance,  since  the  ore-deposits  are  restricted  to  the 
Tertiary  rhyolite  that  covers  so  large  a  part  of  the  district.  The 
total  thickness  of  the  various  rhyolite  flows  thus  poured  out 
on  the  surface  approximates  closely  to  7,500  feet.  A  few  thin  floors 
of  basalt  are  interbedded  with  the  rhyolite,  and  a  single  dacite 


534 


NORTH    AMERICA. 


flow  occurs  near  the  top  of  the  volcanic  series.  Dark  olivine-basalt 
dykes  are  numerous,  but  appear  to  have  exercised  no  influence  on 
ore-deposition.0  The  rhyolite  rocks  of  the  mining  district  proper  are 
traversed  by  numerous  intersecting  faults,  forming  in  plan  a  close 
network.  The  ore-zones  lie  for  the  most  part  in  nearly  vertical 
faults,  along  which  run  numerous  thin  quartz  stringers.  The  zones 
vary  in  width  from  10  to  100  feet,  while  the  quartz  and  calcite 
stringers  within  them  are  generally  a  few  inches  wide.     Gold  with 


'ackson. 


Fig.  175.     Geological  Map  of  Ruby  Hill,  Eureka  Mining  District  {Hague). 
G.  Granite.       T.   Rhyolite  Pumice.     Cambrian :  Pq.  Prospect  Mountain  quartzite.   PI.    Prospect 
Mountain  limestone.     Sc.   Secret  Canyon  shale.      H.   Hamburg  limestone.     Silurian:   P.    Pogonip 
limestone.      E.  Eureka  limestone.      Q.   Quarternary.         Scale:    1,600  feet  to  one  inch. 

auriferous  pyrite  is  finely  disseminated  through  the  quartz  gangue. 
As  might  naturally  be  expected  from  the  more  siliceous  nature 
of  the  enclosing  rock,  siliceous  replacement  of  vein-walls  is  not  so 
common  as  at  Goldfield. 

Lincoln  County. — Lincoln  county  is  the  most  southerly  in 
Nevada.  Its  principal  camps  are  Crescent,  Searchlight,  Eagle 
Valley,  Ferguson,  and  Pioche.  The  Searchlight  field  is  in  hornblende- 
andesite,  but  some  of  its  veins,  as  the  Quartette,  pass  into  an 
adjacent  ancient  gneiss  with  which  is  associated  quartz-monzonite. 


a  Emmons,  W.  H.,  and  Carrey,  Bull.  U.S.  Geol.  Surv.,  No.  303,  1907,  p.  43. 


NEVADA. 


535 


The  Quartette  lode  is  a  soft  mass  of  shattered  country  carrying 
quartz,  galena,  chalcocite,  wulfenite,  chrysocolla,  azurite,  and  their 
normal  oxidised  products.  Eldorado  Canyon  lies  20  miles  further 
north  and  at  the  northern  end  of  the  gneiss  and  quartz-monzonite 
belt  mentioned  above.  Here  the  auriferous  lodes  are  in  the  gneissic 
rocks,  but  at  no  great  distance  from  their  contact  with  basalts 
and  rhyolitic  flow  breccias.  The  veins  of  Crescent,  west  of 
Searchlight,  are  also  in  gneissic  rock.a  The  richest  mine  in 
Lincoln  County  in  1906  was  the  Bamberger  Delamar,  Ferguson 
County,  which  was  surpassed  in  yield  for  Nevada  only  by  the 
leading  mine  at  Goldfield  and  at  Tonopah  respectively.  In  1906, 
Searchlight  field  produced  £106,556  ($519,785)  in  gold. 

Eureka. — In  northern  Nevada  goldfields  are  few  and  scattered. 
The  Tuscarora  camp  was  for  long  an  important  centre,  but  is  now 
almost  deserted.      Its   produce  was   mainly  silver,   derived  from 


J'hoenix  Min  e 


Fia.  176.     Cross-section  in  Phcenix  Mine,  Eureka  (Hague). 
1.  Quartzite.       2.  Crushed    Limestone.       3.    Limestone.      4.    Shale.       5.  Rhyolite. 

lodes  in  a  decomposed  hornblende -andesite.  By  far  the  most 
important  of  the  north-eastern  fields  is  Eureka,  in  Eureka  County, 
famed  in  the  'seventies  for  its  extraordinary  silver-lead  production. 
The  development  of  the  field  was  long  hindered  by  smelting 
difficulties.  In  its  early  years  its  ores  carried  on  an  average  45  per 
cent,  lead,  £12  to  £16  ($60  to  $80)  silver,  and  £3  to  £4  ($15  to  $20) 


a  Ransome,  Bull.  U.S.  Geol.  Surv.,  No.  303,  1907,  p.  68. 


536 


NORTH    AMERICA. 


gold  per  ton,  while  the  pig  lead  thus  produced  contained  £10  ($80) 
gold  per  ton.  After  1884  the  production  decreased  rapidly,  but  to 
t  he  year  1882  there  had  been  obtained  225,000  tons  lead,  £8,000,000 
($40,000,000)  silver,  and  £4,000,000  ($20,000,000)  gold,  nearly  all 
derived  from  pockets  in  the  limestone  of  Ruby  Hill.a 

The  rocks  of  Eureka  are  Palaeozoic  quartzites,  limestones, 
and  shales,  much  faulted  and  displaced,  and  intruded  and  covered 
by  igneous  rocks  (andesites  and  rhyolites).  Ore-deposition  has  taken 
place  through  a  vertical  thickness  of  17,000  feet  of  strata  :  from 
Cambrian  limestone  through  Silurian  limestone  and  quartzite  to 
Devonian  limestone.  The  most  productive  mines  are,  however,  in 
the  Cambrian  rock,  a  feature  arising  merely  from  the  ease  with 
which  that  limestone  was  affected  by  orographic  and  structural 
agencies.  Ore-deposition  took  place  after  the  extrusion  of  the 
igneous  rocks,  and,  according  to  Hague, b  is  to  be  associated  with 
rhyolitic  rather  than  with  andesitic  rocks.  The  ores  were 
originally  deposited  as  sulphides  and  in  depth  are  found  as 
such. 

The  total  gold  production  of  Nevada  to  1900  inclusive  is 
estimated c  at  some  $250,000,000  or  £51,250,000. 

Later  yields  are  : — 


Tear. 

Value,  Dollars. 

Value,  Sterling. 

1901 

$2,963,800 

£607,579 

1902 

2,895,300 

593,536 

1903 

3,388,000 

694,540 

1904 

5,060,494 

1,037,401 

1905 

5,359,100 

1,098,615 

1906 

10,470,704 

2,146,494 

1907 

14,704,658* 

3,014,454 

Grand  total. . 

$294,842,056 

£60,442,619 

*  Estimated ;  Prel.  Rep.  Dir.  U.S.  Mint,  Jan.,  1908. 


ARIZONA. 

Little  is  known  of  the  details  of  the  geology  of  the  auriferous 
occurrences  of  Arizona,  except  indeed  where  the  gold-quartz  veins 
are  associated  with  the  great  copper  deposits  of  the  south-eastern 
portion  of  the  territory.  The  gold-producing  counties  of  Arizona 
are  Yavapai,  Mohave,  Cochise,  and  Yuma,  the  first-named  in  1905 
furnishing  50  per  cent,  of  the  total  yield  for  that  year.    The  general 


a  Ingalls,  Eng.  Min.  Jour.,  Dec.  7,  1907,  p.  1051. 
6  Mom.  XX,  U.S.  Geol.  Surv.,  1892,  P.  294. 
c  Lindgren,  loc.  cit.,  p.  839. 


ARIZONA.  537 

geology  of  the  metalliferous  regions  is  simple.  Short  desert  ranges 
occur  with  cores  of  pre-Cambrian  schists,  granites,  and  gneisses 
overlain  by  Palaeozoic  limestones  and  quartzites,  all  being  intruded 
by  numerous  porphyry  dykes  of  late  Cretaceous  or  early  Tertiary 
age.  Wide  areas  are  covered  with  later  Tertiary  lavas  of  the  same 
age  and  type  as  those  described  from  the  Nevada  goldfields.  Four 
principal  auriferous  areas  may  be  distinguished  in  Arizona:  (1) 
the  vicinity  of  Tombstone,  Cochise  County;  (2)  north  and  south  of 
Tucson  for  some  30  miles  ;  (3)  the  Weaver  mountains  south  of 
Prescott  ;  and  (4)  the  Harqua  Halla  mountains  40  miles  to  the 
south-west   of   the  last   preceding. a 

The  rocks  of  the  Tombstone  district  are  limestones  and 
quartzites  in  alternating  order  but  with  shale  as  the  upper- 
most member.  These  are  folded  into  anticlines  and  synclines. 
Dykes  of  granophyric  character  are  intrusive  through  and 
into  the  sedimentary  series.  The  most  productive  mines  lie 
within  the  sedimentary  rocks,  at  some  distance  from  the 
contact  with  the  main  granitoid  mass.  The  ore-deposits  are 
essentially  replacements  along  fissures  in  the  sedimentary 
rocks.  Most  of  the  rich  ore  has  been  found  along  anticlinal  axes. 
About  one-half  of  the  gold  and  silver  produced  in  Tombstone 
has  been  derived  from  deposits  in  the  upper  shales,  and  most  of  the 
remainder  from  limestones,  very  little  being  furnished  by  quartzites. 
The  sedimentary  rocks  are  covered  near  the  mineral  area  by  rhyolite, 
in  which  rock  is  developed  the  vein  of  the  well-known  Common- 
wealth mine,  18  miles  north-east  of  Tombstone.  In  the  Tombstone 
district  two  important  veins,  Lucky  Cuss  and  Knoxville,  occur  near 
a  granodiorite  contact.  There  is,  nevertheless,  no  apparent  con- 
nection between  ore  deposition  and  igneous  rock,  whether  grano- 
diorite or  granophyre.  The  principal  vein  of  the  district — one  that 
has  yielded  ore  to  the  value  of  nearly  £2,500,000— is  4,000  feet 
away  from  the  eruptive  mass.  The  entire  gold  yield  of  Tombstone 
to  1902  is  estimated  at  163,000  ounces.  During  the  same  period  its 
silver  yield  was  21,500,000  ounces. b 

The  Mammoth  veins,  north-east  of  Florence,  in  Pinal  County, 
and  in  former  years  notably  rich  in  gold,  are  associated  with  a 
rhyolite  dyke  in  granite  country.  South  of  Prescott,  Yavapai 
County,  numerous  veins  are  found  in  the  pre-Cambrian  rocks. 
The  Congress  is  the  best-known  mine  in  this  area.  Its  veins  are 
pyritous  and  are  within  granitic  rocks. c     The  Socorro,  Gold  King, 

a  Pratt,  Eng.  Min.  Jour.,  June  7,  1902,  p.  795. 

h  Church,  Trans.   Amer.  Inst.  M.E.,   XXXIII,   1903,  p.   3. 

c  Lindgren,  lb.,  p.   814. 


538 


NORTH    AMERICA. 


and  Fortuna  mines,  further  west,  are  also  in  similar  country.  Reida 
describes  the  mines  of  the  Cherry  Creek  district  in  Central  Arizona 
as  occurring  in  broken  and  sheeted  zones  in  granite-porphyry  dykes 
in  the  main  mass  of  Algonkian  biotite-granite.  The  latter  shows 
the  same  relations  to  the  overlying  limestone  as  in  the  magnificent 
and  often-described  Grand  Canyon  of  the  Colorado  river 
further  north.  The  surface  ores  of  Cherry  Creek  are  free- 
milling.  The  much  better-known  United  Verde  mine  at  Jerome, 
Hi  miles  north  of  Cherry  Creek,  was  first  worked  as  a  gold 
mine  and  showed  no  copper  in  the  outcrop.  In  depth,  however, 
the  latter  metal  became  predominant,  and  is  now  almost  the  sole 
product. 

The  total  gold  production  of  Arizona  to  1900  is  estimated  at 
£8,610,000  ($42,000,000).    Later  returns  are  :— 


Year. 

Value,  Dollars. 

Value,  Sterling. 

1901 
1902 
1903 
1904 
1905 
1906 
1907 

$4,083,000 
4,112,300 
4,357,600 
3,478,532 
2,691,300 
2,964,683 
2,539,516* 

£837,015 
843,021 
893,308 
713.099 
551,716 
607,760 
520,600 

Grand  total  .  . 

$66,226,931 

£13,576,519 

*  Estimated. 


COLORADO. 


Colorado  has  been  for  many  years  the  leading  State  of  the  Union 
in  respect  of  its  gold  production.  Its  pre-eminence  has,  however,  been 
seriously  challenged  during  1906  and  1907  by  the  territory  of  Alaska, 
but  as  the  latter  region  is  dependent  entirely  on  its  readily  exhaus- 
tible alluvial  gold,  serious  rivalry  will,  in  all  likelihood,  not  long  be 
maintained.  The  commanding  position  of  Colorado  is  due  principally 
to  the  well-sustained  production  of  the  famous  Cripple  Creek 
district,  on  the  western  slopes  of  Pike's  Peak.  This  field,  discovered 
in  1892,  reached  its  maximum  production  eight  years  later  with  an 
output  for  1900  of  £3,705,077  ($18,073,539),  the  greatest  gold 
production  for  a  single  year  of  any  field  in  the  United  States.  The 
equally  celebrated  Comstock  mines,  even  in  1877,  when  in  the  hey- 
day of  their  prosperity,  produced  about  £700,000  ($3,500,000)  less. 
Ninety-seven  per  cent,  of  the  gold  of  Colorado  comes  from  quartzose 


a  Econ.  Geol.,  I,  1906,  p.  428. 


COLORADO.  539 

ores,  the  remainder  (45,000  ounces  for  the  year  1906)  being  derived 
as  a  by-product  from  the  smelting  of  lead,  zinc,  and  copper  ores. 

The  metalliferous  wealth  of  Colorado  may  be  attributed  to 
the  folding  and  extensive  orogenic  movements  to  which  the  rocks  of 
the  western  portion  of  the  State  have  been  subjected,  accompanied 
as  they  were  in  Tertiary  times  by  volcanic  intrusions  and  eruptions 
that  were  attended  or  followed  by  the  widespread  percolation 
of  ore-bearing  solutions.  While  deposition  may  have  and  did  take 
place  in  the  Palaeozoic  and  Mesozoic  sedimentary  rocks,  the  valuable 
deposits  of  Colorado  nevertheless  lie  in  the  Tertiary  propylitic  rocks. 
Moreover,  even  in  the  former  case,  the  ore-deposition  is  generally 
ascribed  to  the  influence  of  an  adjacent  Tertiary  intrusive  rock. 
Deposits  in  the  older  rocks  are  more  abundant  in  the  northern 
counties  of  Boulder,  Clear  Creek,  and  Gilpin,  while  those  in 
the  younger  rocks  prevail  in  the  Cripple  Creek  district  and  also  in 
the  rich  San  Juan  region  in  the  south-west.  The  leading  counties 
with  their  principal  fields,  in  order  of  gold  production,  are  Teller 
(Cripple  Creek)  Ouray  (Camp  Bird),  San  Miguel  (Telluride),  Gilpin, 
Lake  (Leadville),  and  San  Juan  (Silverton).  Each  of  these  counties 
produces  more  than  a  million  dollars  annually. 

Boulder  County. — The  mines  of  Boulder  County  lie  on  the 
foothills  of  the  Rocky  Mountains,  some  30  to  35  miles  north-west 
of  Denver.  Their  elevation  above  sea-level  is  from  6,500  to  8,500 
feet.  The  fundamental  rocks  of  the  eastern  foothills  are  granite, 
gneiss,  and  mica-schist,  through  which  there  have  been  extruded 
andesite,  trachyte,  rhyolite,  and  phonolite.  The  ore-deposits 
normally  occur  in  fissure  lodes  in  the  older  rocks,  or  at  contacts  of 
sedimentary  and  igneous  rocks.  The  high-grade  ore  occurs  in  irregular 
shoots,  and  may  be  free-milling  gold-ore,  changing  in  depth  to 
sulphide-ore  ;  or  the  values  may  be  in  tellurides  of  gold  and  silver 
(petzite,  calaverite,  sylvanite).  The  first  discovery  of  gold-telluride 
(petzite)  in  Colorado  was  made  by  Dr.  Anton  Eilers  in  1871,  when 
examining  ore  from  the  Red  Cloud  mine.a  An  example  of  normal 
gold-occurrence  is  the  Golden  Age  vein,  near  Jamestown,  at  the 
contact  of  a  quartz-porphyry  dyke  with  granite  and  gneiss.  The 
gangue  is  the  bluish  horn-quartz  of  the  telluride  ores  of  Boulder 
County.  Free-gold  ores  also  occur  in  close  proximity.  The  values 
are  distributed  in  irregular  shoots,  and  the  veins  on  the  whole  are 
rich  but  uncertain. &  The  Smuggler  mine  in  the  same  county  has 
been  worked  since  1880,  and  had  produced  to  1891  more  than 
£400,000  ($2,000,000)  gold.  Its  lode  is  a  fissure  vein  in  mica-schist 
and  carries  its  value  in  high-grade  tellurides,  mainly  sylvanite.0 

a  Genth,  Amer.  Jour.  Sci.,  2,  XLV,  p.  305. 

b  Owen,  Trans.  Inst.  M.E.,  XIX,  1900,  p.  325. 

r'Farish,  Trans.   Amer.  Inst.   M.E.,   XIX,   1891,  p.   547. 


5-iO  NORTH    AMERICA. 

Gilpin  County. — In  Gilpin  County,  the  next  to  the  south, 
gold-quartz  veins  are  found  in  rocks  similar  to  those  of  Boulder 
County.  The  ores  are  free  gold,  with  highly  auriferous  pyrite  and 
chalcopyrite.  Attention  was  first  directed  to  the  district  by  the  rich 
placers  of  the  streams.  The  mining  area  is  extremely  small,  covering 
only  about  16  square  miles  in  the  immediate  neighbourhood  of 
Central  City.  It  has,  nevertheless,  been  exceedingly  productive 
in  the  past. 

Clear  Creek  County. — Considerable  geological  work  has 
been  done  in  the  mining  areas  of  Clear  Creek  County,  and 
the  geological  relations  of  the  various  rocks  have  therefore 
been  made  fairly  evident. a  The  older  rocks  of  the  Idaho 
Springs  and  Georgetown  districts  form  the  presumably  pre- 
Cambrian  complex  of  the  Front  Range  of  the  Rocky  Mountains. 
They  are  biotite-  or  quartz-gneisses  and  schists,  granites, 
pegmatites,  and  basic  igneous  rocks  resembling  diorites  and 
amphibolites.  These  rocks  are  intruded  by  numerous  felsitic  and 
granitic  porphyries,  that  are  clearly  older  than  the  period  of  the 
prevalent  ore-deposition.  The  ores  are  pyrite,  galena,  blende,  and 
chalcopyrite.  The  gold  is  occasionally  free,  but  is  more  often 
combined  with  the  sulphides.  The  chief  gangue  mineral  is  quartz, 
with  which  is  associated  subordinate  siderite,  barytes,  calcite, 
rhodochrosite,  and  magnesite.  Many  veins  are  connected 
with  the  porphyry  dykes,  but  apparently  merely  because  the 
dyke  intrusion  has  formed  parallel  fissures  or  planes  of 
weakness  in  the  country  along  which  the  veins  have  been 
deposited.  Pay-shoots  are  met  with  most  often  at  the 
intersections  of  the  larger  veins  or  of  feeders  with  the  main 
veins,  where  ore-bearing  solutions  have  been  mingled,  with  con- 
sequent precipitation  of  their  burden.  From  the  foregoing  it  will 
thus  be  apparent  that  the  counties  of  Boulder,  Gilpin,  and  Clear 
Creek  form  a  single  mining  field  contained  within  Archaean  rocks, 
but  with  a  mineralisation  to  be  ascribed  to  a  much  later  date. 

Summit  County. — The  next  county  to  the  south-west  is 
Summit.  Its  principal  camps  are  Breckenridge  and  the  Ten-mile 
district,  both  in  the  south  of  the  county.  Placer-mining  and 
dredging  are  being  carried  on  near  the  former  place,  but  its  deep 
mines  are  much  more  important,  producing  silver-gold-lead  ores 
to  the  value  of  £50,000  per  annum.  Breckenridge  is  almost  unique 
among  North  American  goldfields,  inasmuch  as  its  veins  furnish 
remarkably     well-crystallized     gold     from     pockets     in     narrow 

a  Spun-    and    Garrey,  Bull.    U.S.  Geol.    Surv.,    No.    260,    1905,    p.    99  ;     Id.,   ib., 
No.   285,   190G,  p.   35. 


COLORADO. 


541 


lenticular  veinlets  lying  in  uptilted  black  marine  Cretaceous  slates 
or  shales  that  are  traversed  by  porphyry  dykes.  One  such  pocket 
is  said  to  have  yielded  nearly  £6,000  ($29,000),  mostly  obtained 
by  simply  scraping  out  the  contents  of  a  vugh.a  The  Ten-mile 
or  Kokomo  district  is  mainly  a  silver-lead-zinc  field,  but  gold  is  also 
produced.  The  ore-deposits  occur  as  veins  or  "  blankets  "  in  a 
series  of  Carboniferous  limestones  and  sandstones  intruded  by  sheets 
of  diorite-porphyry.  The  sulphides  are  pyrite,  marcasite,  galena, 
and  zinc  blende.6  Similar  ores,  also  in  Carboniferous  limestones 
intruded  by  diorite-porphyry  are  worked  near  Alma,  London,  &c, 
a  few  miles  to  the  south  of  the  Ten-mile  district,  but  in  Park  County. 

Leadville. — The  Leadville  mines  of  Lake  County  produce,  in 
order  of  decreasing  value,  zinc,  silver,  lead,  gold,  and  copper.  Its 
gold  production  for  1905  is  estimated0   at  £241,982  ($1,180,401). 


Wliiw  Porphyry. 


EH 

Gray  Porphyry. 


Blue  Limestone. 


Vein       Ore 
material 


Fig.    177.     Section  through  Florence  Mine,  Printer  Boy  Hill,  Leadville  {Emmons). 

The  ores,  being  sulphides,  are  generally  treated  by  concentration 
and  subsequent  smelting.  Mining  commenced  in  this  district  with 
the  discovery  in  1859  of  the  rich  placers  of  California  Gulch,  from 
which  large  quantities  of  alluvial  gold  were  won  for  three  or  four  years. 
With  their  exhaustion  the  field  was  practically  deserted,  for  the  rich 
silver-lead  deposits  that  have  since  made  Leadville  famous  were  not 
discovered  until  1875.  By  1880,  however,  most  of  the  richer  mines 
were  yielding  enormous  quantities  of  silver  and  lead.  The  economic 
geology  of  the  district  is  described  in  one  of  the  classic  monographs 
of  the  United  States  Geological  Survey.^  The  basement  rocks  are 
crystalline  Archaean  gneiss,  granite,  and  amphibolite.  These  are 
overlain  by  several  thousand  feet  of  sedimentary  strata,  including 


a  Lakes,  Mines  and  Minerals,   Dec.,   1900,   p.   222. 

b  Emmons,  S.  F.,  Atlas  U.S.  Geol.  Surv.,  Fol.  48,  1896,  p.  5. 

cLindgren,Min.  Res.   U.S.,  1906,  p.  204. 

d  Emmons,  S.   F.,  Mon.   U.S.   Geol.   Surv.,  XII,   1886. 


542 


NORTH   AMERICA. 


Cambrian  quartzite,  Silurian  blue  or  dark  limestone  (the  chief 
ore-horizon),  Lower  Carboniferous  grits,  Upper  Carboniferous  blue 
limestone,  and  Quaternary  lacustrine  deposits. 

All  the  Palaeozoic  strata  were  caught  up  in  the  early  Tertiary 
uplift  of  the  Rocky  Mountain  zone,  were  folded  and  crushed,  and 
were  intruded  by  porphyry  dykes  and  sheets.  To  the  influence  of 
the  intrusive  igneous  rocks  the  ore-deposits  are  probably  to  be 
ascribed.    The  ore-bodies  are  generally  situated  beneath  the  contact 


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Fig.  178.     Geological  Map  or  Bassick   Hill,  Colorado  (Cross). 

1.  Rhyolite.     2.  Trachyte.    3.  Bassick  andesitic  agglomerate.    4.  Bunker  andesite.     5.  Rosita 
andesitic  tuff  and  breccia.     6.  Granite  and  gneiss. 


of  the  porphyry  sheet  with  the  underlying  blue  limestone.  The  free- 
gold  lodes  of  Leadville  are  best  exemplified  on  Printer  Boy  Hill,  where 
they  occur  in  connection  with  a  body  of  porphyry  not  identical  with 
any  other  found  in  the  district.  The  Printer  Boy  vein  was  discovered 
as  early  as  1866.  It  lies  within  the  porphyry  in  a  vertical  fissure 
plane,  and  varies  in  width  from  a  few  inches  to  3  feet.  Similar  veins, 
also  in  the  porphyry,  are  found  in  the  vicinity.  In  1907  important 
gold  discoveries  were  made  in  the  Breece  Hill  district. a 


aRickard,  F.,  Min.  Sci.  Press,  Jan.   11,   1908,  p.  70. 


COLORADO. 


543 


Chaffee  County. — Auriferous  veins  occur  near  Granite  and 
Buena  Vista  in  the  north  of  Chaffee  County,  where  a  few  small 
placers  are  also  worked.  Little  is  known  of  the  geology  of  the 
district.  In  Saguache  County,  a  little  gold  is  being  obtained  near 
Crestone  in  the  western  foothills  of  the  Sangre  de  Cristo  range. 

Custer  County. — The  Rosita  and  Silver  Cliff  districts,  Custer 
County,  lying  40  miles  south  of  Cripple  Creek,  and  on  the  western 
foot-hills  of  the  Wet  Mountain  range,  present  many  analogies  with 
the  more  famous  Cripple  Creek  occurrences.  The  conditions  under 
which  the  ores  occur  are  sufficiently  remarkable  to  merit  a  slight 
amount  of  detail.  The  peculiar  features  of  occurrence,  features  that 
are  indeed  repeated  several  times  in  the  district,  are  perhaps  best 
shown  in  the  Bassick  mine,a   which   worked  on  two  chimney-like 


Fig.  179.     Geological  section  through  Bassick  Mine  and  neighbourhood  (Cross). 

1.  Rhyolite.      2.    Trachyte.     3.   Bassick  andesitic  agglomerate.      4.  Bunker  andesite. 

5.  Rosita  andesitic  tuff  and  breccia.      6.  Granite  and  gneiss. 

ore-deposits.  The  basement  rock  of  the  district  is  granite  and 
gneiss.  Through  these  Archaean  rocks,  and  possibly  along  a  vertical 
line  of  weakness  resulting  from  the  intersection  of  two  faults 
or  fissures,  an  Eocene  volcano  burst  forth  with  eruptive  violence, 
making  for  itself  an  elliptical  conduit  in  the  metamorphic  rock. 
Through  the  rent  lavas  welled  and  ashes  were  thrown  to  the  surface. 
The  lavas  varied  in  character  ;  the  order  of  the  succession  from  the 
oldest  to  the  youngest  appears  to  have  been  andesite,  diorite  (dykes), 
dacite,  rhyolite,  andesite,  trachyte,  and  andesitic  agglomerate. 
Part  of  the  f  ragmental  material  is  well  stratified,  and  was  apparently 
deposited  on  lake-beds.  The  Bassick  mine  itself  lies  on  the  slope 
of  Mount  Tyndall,  its  andesitic  agglomerate  being  partially  pro- 
tected from  erosion  by  a  rhyolite  flow  that  forms  the  cap  of  the 
mountain.  The  fragments  of  the  agglomerate  range  in  size  up  to 
3  feet.  Two  nearly  vertical  agglomerate  chimneys,  formed  as  above 
described,  lie  within  a  short  distance  of  each  other  in  the  gneiss  ; 
both"  have  been  worked.  The  larger  is  rudely  elliptical  in  horizontal 
section,    with    major   and    minor   axes    of    75    and    25    feet    long 


a  Cross,  17th  Ann.  Rep.  U.S.  Geol.  Surv.,  II,  1896,  p.  263;    Emmons,   S.    F„  ib., 
p.  411  ;    Welles  and  Lakes,  Mines  and  Minerals,  June,  1903,  p.  487. 


544 


NORTH    AMERICA. 


respectively.  Towards  the  walls  of  the  vent  a  considerable  admixture 
of  gneissic  fragments  has  taken  place.  The  ore-body  itself  lies  within 
the  agglomerate,  filling  the  throat,  and  with  its  richest  ore  near 
the  centre,  where  also  are  disposed  the  larger  fragments  of  andesite. 


NEW  SHAFT 

~f 


Fig.  180.     Cross-section  through 

ORE-BODY   OF  BaSSICK   MlNE 

(Emmons). 


/■  W*&V&,'iJ!,>' 


Fig.  181.     Cross-section  of  Bull-Domixgo  Chimney 
Custer  Co.,  Colorado  (Emmons). 


These  last  are  well-rounded  and  bear  every  indication  of  having 
undergone  considerable  attrition  within  the  vent.  The  walls  of  the 
ore-body  are  by  no  means  distinct,  and  its  general  downward  course, 
which  is  not  always  exactly  in  the  centre  of  the  chimney,  is  believed 
by  Emmons  to  have  been  determined  by  the  intersection  of  fracture 
planes.    The  ores  found  in  the  vent  are  blende,  galena,  jamesonite, 


COLORADO  545 

tetrahedrite,  smithsonite,  calamine,  and  free  gold,  with  relatively 
insignificant  quantities  of  quartz  and  calcite.  The  disposition  of  the 
ore  is  remarkable.  The  sulphides  are  arranged  in  concentric  shells 
of  constant  local  thickness  (from  one-fourth  inch  and  less  to  2  inches) 
of  different  sulphides  that  are  always  disposed  in  the  same  order 
around  the  more  or  less  rounded  agglomerate  fragments.  The 
innermost  shell  is  composed  of  sulphides  of  zinc,  antimony,  and 
lead,  containing  on  an  average  60  ounces  silver  and  1  to  3  ounces 
gold.  It  is  succeeded  by  a  second  layer  with  more  gold,  silver, 
and  lead,  often  as  much  as  100  ounces  of  the  first  and  200  ounces 
of  the  second  per  ton.  A  third  layer  or  shell  of  crystalline  blende  with 
some  iron  and  copper  sulphide  forms  the  most  valuable  ore  in  the 
mine,  having  an  average  tenor  of  15  to  20  ounces  gold  and  60  to  120 
ounces  silver  per  ton.  This  is  generally  the  outermost  shell,  but 
there  may  also  occur  further  successive  shells  of  chalcopyrite 
and  of  pyrite  respectively.  The  interstitial  matter  connecting 
the  agglomerate  fragments  is  mainly  kaolin,  through  which  is  loosely 
disseminated  tetrahedrite  (grey  copper)  and  tellurides  of  gold  and 
silver,  obviously  the  last  products  of  the  solfataric  action  that  had 
deposited  the  ores.  The  Bassick  ore-body  has  been  followed  in 
depth  within  the  chimney  to  nearly  2,000  feet.  Carbonised  and 
partly  silicified  wood  has  "been  found  at  a  depth  of  765  feet  from  the 
present  surface.  The  Bull-Domingo  mine,  at  Silver  Cliff,  is  working 
on  a  similar  volcanic-throat  agglomerate.  Its  ores  show  the  same 
characteristic  disposition  in  concentric  shells  of  different  sulphides 
round  andesitic  fragments.  The  ores  of  the  Bull-Domingo  are, 
however,  mainly  argentiferous  and  contain  little  gold.  The  Bassick 
mine  was  opened  in  1877.  Since  then  it  has  yielded  more  than 
£512,500  ($2,500,000)  in  gold  and  silver. 

Costilla  County. — In  Costilla  County  an  auriferous  area 
occurs  at  Plomo  on  the  Rito  Seco,  north-east  of  San-Luis,  and  on 
the  western  slope  of  the  southern  Sangre  de  Cristo  range.  Here 
the  ore-bodies  occur  in  granite-gneiss  along  zones  of  siliceous  and 
pyritous  replacement.  The  ores  are  low-grade,  ranging  in  value 
from  10s.  ($2.50)  to  30s.  ($7.50)  per  ton.« 

Cripple  Creek. -^The  Cripple  Creek  district,  from  1893  to 
1908  the  leading  gold  camp  in  the  United  States,  lies  on  the  western 
slopes  of  Pike's  Peak  at  a  general  elevation  of  some  10,000  feet 
above  sea-level.  It  may  be  reached  by  several  railway  routes, 
of  which  the  Cripple  Creek  Short  Line  from  Colorado  Springs  is 
perhaps  the  most  convenient,  and  is  certainly  the  most  picturesque. 

aGunther,  Econ.  Geol.,  I,   1906,  p.   151. 
Ll 


546 


NORTH   AMERICA. 


The  earliest  report  of  the  gold  in  this  region  induced  a  celebrated 
rush  to  Pike's  Peak  as  long  ago  as  1859,  a  rush  that  ended  in 
failure  and  even  in  disaster.  The  district  was  practically  aban- 
doned by  miners  until  1891,  when  various  Colorado  Springs  pros- 
pectors discovered  gold  and  gold-tellurides  and  marked  out  claims 
that  have  since  proved  of  extraordinary  value. a  From  that  time 
onward  the  development  of  the  district  was  exceedingly  rapid  and 


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I'm.  182.     Geological  Map  of  the  Cripple  Creek  Goldfield,  Colorado  (Ransome  and  Gralon) 

1.  Alluvium.    2.  Trachydolerite.    3.  Phonolite.    4.  Latite-phonolite.    5.  Syenite. 
G.  Phonolite-breccia.     7.  Granite.     8.  Gneiss  and  schist. 

its  yield  increased,  as  has  already  been  noted,  until  1900,  when 
the  annual  output  reached  £3,705,075  ($18,073,539).  The  general 
progress  of  the  field  has  at  times  been  somewhat  retarded  by  labour 
troubles.  These  became  especially  serious  in  1894  and  again  in 
1903.  The  amount  of  the  total  dividends  paid  by  the  various 
mines  is  not  ascertainable  with  accuracy,  but  to  the  end  of  1903  is- 
believed  to  have  been  £6,714,160  ($32,752,000).  The  goldfield  is  a 
small  one,  being  comprised  entirely  within  a  circle  with  a  radius  of 
three  miles  from  Gold  Hill. 


"  Rickard,  T.  A.,  Trans.  Inst.  Min.  Met.,  VIII,  1899,-  p.  49. 


COLORADO.  547 

The  oldest  rocks  in  the  district  are  fibrolite-muscovite  schists 
and  fine-grained  granitic  gneisses.  On  these  the  greater  portion 
of  the  town  of  Cripple  Creek  is  built.  Associated  with  the  older  rocks 
and  intrusive  into  them  are  granites  of  three  types  :  Pike's  Peak, 
Cripple  Creek,  and  Spring  Creek,  differing  mainly  in  texture.  These 
have  not  been  differentiated  on  the  accompanying  geological  sketch 
map,  and  the  older  rocks  generally  are  of  interest  only  in  so  far  that 
they  form  the  basement  rocks  of  the  district  through  which  the 
Tertiary  eruptives  have  broken.  At  the  time  of  eruption  the 
country  appears  to  have  been  a  granitic  plateau  similar  in  most 
respects  to  that  existing  at  the  present  day.  The  Tertiary  eruptive 
magmas  broke  with  explosive  violence  through  a  narrow  short  vent, 
shattering  to  fragments  the  overlying  granites  and  brecciating 
those  in  the  immediate  vicinity,  much  of  the  debris  falling  back 
into  the  vent.  Following  the  first  explosions  came  eruptions  of 
phonolite,  latite-phonolite,  and  syenite,  the  products  of  which  were 
subsequently  shattered  and  comminuted  in  the  vent  by  later 
eruptive  paroxysms.  The  materials  in  the  throat,  at  least, 
were  therefore  thoroughly  mingled.  At  the  same  time  a 
volcanic  cone  was  built  up  on  the  surface.  Of  this  cone  but  little 
trace  now  remains,  nearly  all  of  it  having  disappeared  before 
the  agencies  of  erosion.  Thus  the  accompanying  geological 
map  shows  rather  the  plan  of  the  original  throat  than  the  wider 
extent  of  the  now  vanished  cone.  The  volcanic  breccia  forming  the 
principal  portion  of  the  throat-filling  is  generally  a  structureless 
agglomeration  of  ash  and  larger  fragments.  Banding,  however, 
occurs  in  places,  as  at  the  220-foot  level  of  the  Portland  mine. 
Carbonaceous  and  silicified  material  representing  original  tree  trunks 
have  been  found  at  depths  of  from  500  to  800  feet  below  the  present 
surface,  and  show  that  a  forest  grew  on  the  site  of  the  crater  or  that 
it  flourished  on  the  crater  slopes  between  eruptions. 

In  addition  to  the  breccia,  intrusive  masses  of  latite-phonolite 
and  syenite  are  found  in  the  throat.  The  former  occurs  mainly 
as  irregular  stock-like  bodies  or  in  thick  sheets.  The  syenite  is 
genetically  connected  with  the  latite-phonolite  and  is  merely  a 
different  facies  of  the  same  intrusive  mass.  Though  differentiated 
on  the  map,  they  are  therefore  closely  related  masses  and  shade 
the  one  into  the  other  in  position,  texture,  and  composition. 

The  dense  black  aphanitic,  typical  trachy-dolerite  found  on 
Bull  Hill  is  apparently  younger  than  the  latite-phonolite.  Nearly  all 
the  large  intrusive  masses  composing  the  throat-breccia  are  latite- 
phonolite,  occurring,  as  on  Beacon  Hill,  as  plugs  in  elliptical  chimneys 
in  the  granite.  The  breccia,  the  latite-phonolite,  and  the  surrounding 
pre-Cambrian  rocks  are  all  cut  by  exceedingly  numerous  thin 
phonolitic  dykes  of  different  ages,  that  have  had    a  considerable 


548 


NORTH    AMERICA. 


economic  effect  on  ore-deposition.  The  last  eruptions  from  the 
Cripple  Creek  vent  were  basic  dykes  showing,  like  the  phonolite  dykes, 
a  tendency  to  radiate  from  a  centre.  They  may  be  trachydolerite, 
vogesite,  or  monchiquite.  These  basic  dykes  (termed  by 
Stevens"  nepheline-basalt,  limburgite,  felspar-basalt,  and  tephrite) 
are  considered  by  him  to  have  also  exercised  a  most  important 
influence  on  ore-deposition.  A  rhyolite  occurs  in  small  scattered 
patches  in  the  south  of  the  district  some  distance  from  the  auriferous 
areas,  and  represents  perhaps  a  portion  of  an  original  surface  flow 
of  probable  Miocene  age  and  therefore  practically  contemporaneous 
with  the  later  activity  of  the  Cripple  Creek  volcano. 

Petrologically  considered,  the  phonolite  is  a  fine-grained,  fairly 
dark,  often  porphyritic,  but  generally  aphanitic  rock.  Its  felspar 
is  soda-orthoclase.  The  distinctive  mineral  is  of  course  nepheline, 
which  occurs  in  large  quantity.  Nosean  and  sodalite  are  also  present, 
as  also  is  analcite,  which  is  here  regarded  as  a  primary  constituent 
of   the   rock.&       The   ferro-magnesian   silicates    are    aegerine    and 


IMW 
a    b  c 


\  * 


♦  ♦ 
t  t 

K  t 


♦  ♦ 


a     9 
a     a 

a 

»   a    * 

*    * 

«    «    " 


Fig.  183.     Section  in  North  Star  Mine,  Cripple  Creek  {Penrose), 
a.  Veins.     6.  Dykes,     c.  Country.     Scale :    1  inch  =  4  feet. 

aegerine-augite,  together  with  an  undetermined  blue  amphibole.  The 
term  latite-phonolite  is  proposed  for  certain  Cripple  Creek  volcanic 
rocks,  to  denote  a  type  intermediate  between  phonolite  and  latite, 
the  latter  term  itself  denoting  a  form  intermediate  between  andesite 
and  trachyte  and  therefore  the  volcanic  equivalent  of  monzonite. 
The  latite-phonolites  contain  therefore  orthoclase,  soda-plagioclase, 
a  soda  felspathoid  (including  analcite)  and  some  mineral  of  the 
pyroxene,  amphibole,  or  mica-groups. c  The  syenites  are  granular 
rocks  closely  resembling  the  latite-phonolite.    They  are  medium  to 


aLoc.   cit.  inf.,    p.   098. 

h  Lindgren,  16th  Ann.  Rep.  U.S.  Geol.  Surv.,  1895,  Pt.  II,  p.    36  ;    Graton,  Prof. 
Paper  No.  54,  U.S.  Geol.  Surv.,  1906,  p.  62. 

c  Graton,  loc.  cit.,  p.  69. 


Plate  XXIX. 


South  slope  of  Bull  Hill,  from  Squaw  Mount,  Cripple  Creek. 


Cripple  Creek,  looking  West  from  Gold  Hill. 
Mount  Pisgah  in  the  background.     (U.S.  Geological  Survey.) 


COLORADO. 


549 


dark-grey  rocks  with  prominent  prismatic  crystals  of  pyroxene  in 
a  felspathic  matrix.  The  last  basic  intrusions  through  the  rocks 
of  the  Cripple  Creek  vent  strongly  resemble  basalts  in  outward 
appearance,  and  are  divided  by  Graton,  because  of  their  high  alkali 
content,  into  trachydolerite,  vogesite,  and  monchiquite,  the  last 
possessing  phenocrysts  of  pyroxene  and  olivine  embedded  in  a  matrix 
of  analcite. 


Fig.    184.     Ore-streaks   (black)  in  Andesite-breccia,   Cripple   Creek   {Richard). 

The  prevalent  breccia  is  wholly  fragmental  and  may  vary  in 
fineness  from  a  tuff  to  an  agglomerate,  the  general  tendency  being 
toward  the  finer-grained  rock.  The  breccia  is  largely  made  up  of 
phonolite  and  latite-phonolite,  but  numerous  granite  fragments 
also  occur.  Granite  brecciated  in  situ  is  also  found  on  the  walls 
of  the  original  vent.  The  activity  of  the  volcano  seems  to  have  been 
greatest  in  Miocene  times. 

On  the  whole,  the  Tertiary  volcanic  rocks  of  the  Cripple 
Creek  metalliferous  area  may  be  regarded  as  having  been 
differentiated  from  a  single  originally  homogeneous  magma. 

The  auriferous  ore-bodies  of  the  district  may  be  divided  into 
two    classes  :     (a)  those   tabular  in    form  and   strictly   following 


550 


NORTH    AMERICA. 


simple  fissures  or  sheeted  zones  in  the  volcanic  breccia,  and  (6) 
irregular  bodies  adjacent  to  fissures  and  formed  by  replace- 
ment and  recrystallization  of  the  country  rock,  which  is,  in  this 
case,  usually  granite.  The  groups  are  not  sharply  defined  and 
may  shade  into  one  another.  Cripple  Creek  fissures  are  always 
narrow  and  are  not  always  filled  with  the  usual  quartz  or  fluorite 
gangue.  Wide  lodes  are  indeed  worked,  but  these  are  essentially 
zones  of  thoroughly  shattered  country  along  which  run  numerous 
narrow  parallel  fissures  thinning  away  to  mere  cracks  in  which  the 
rich  tellurides  are  deposited.  The  country  in  the  vicinity  of  the 
fissures  is  often  replaced  by  dolomite,  pyrite,  and  a  little  fluorite. 
The  fissures  often  remain  unfilled  and  exhibit  a  characteristic 
'vuggy  "  structure.     The  rich  tellurides,  being  the  last  deposited, 


4  ft. 


Fig.  185.     Sheeting  in  Breccia,  Captain  Vein,  Portland  Mine,  Cripple  Creek  (Lindgren). 


are  generally  found  on  the  walls  of  the  "  vughs  "  or  fissures. 
Sheeted  zones  and  single  fissures  are  also  well  developed  and  are 
profitably  worked  in  the  surrounding  granite,  as  in  the  El  Paso, 
C.  K.  &  N.,  and  Gold  Coin  mines.  They  often  follow  phonolite  dykes 
that,  by  their  intrusion,  have  induced  parallel  fracturing  in  the 
country.     In  the  sheeted  zones,  the  ore  may  occur  in  pay-shoots 


COLORADO. 


551 


2,000  feet  long  and  1,000  feet  deep,  but  is  ordinarily  contained  in 
very  much  smaller  ore-bodies. 

Replacement  deposits  in  granite  occur  near  the  breccia  contacts 
and  are  extensively  worked  in  the  Elkton,  Ajax,  Independence, 
and  Portland  mines.  In  these  cases  the  ore  occurs  both  in  the 
fissures  and  in  the  adjacent  country. 


fy6^  n    8«£CilA  /  FRKTUflE        §B    OKE. 

Fig.  186.     Impregnations  along  parallel  fractures,  Cripple  Creek  (Rickard). 

The  gold-ores  of  Cripple  Creek  are  tellurides,  viz.,  sylvanite, 
krennerite,  and  calaverite,  with  which  are  associated  free  gold 
derived  from  the  foregoing  tellurides,  pyrite  (the  most  common 
sulphide  in  the  district),  molybdenite,  stibnite  (usually  associated 
with  very  rich  ores),  blende,  and  tetrahedrite.  Molybdenite, 
stibnite,  and  tetrahedrite  are  occasionally  very  rich,  but  it  appears 
probable  from  analyses  that  their  gold  content  is  due  to  mechanically 
admixed  calaverite. 

Quartz  is  the  most  important  vein-forming  mineral,  and  occurs 
as  crusts  and  combs.     It  is  frequently  intergrown  with  calaverite. 


552 


NORTH    AMERICA. 


Fluorite,  ordinarily  purple  in  colour,  is  abundant  in  all  veins. 
Dolomite  is  also  common.  Roscoelite,  rhodochrosite,  and  celestite 
are  among  the  most  interesting  of  the  numerous  vein  minerals 
found.  Valencianite  (potash-felspar)  is  common  as  a  secondary 
product  in  the  ores  enclosed  in  the  granite.  The  oxidised  zone 
is  from  200  to  400  feet  in  depth.  The  normal  ores  of  the  district 
contain  1  ounce  silver  to  10  ounces  gold.  Where  galena  and  tetra- 
hedrite  are  abundant  the  proportion  of  silver  rises  considerably. 
The  average  value  of  Cripple  Creek  ore,  as  mined,  is  some  £6  to  £8 
($30  to  $40)  per  ton,  though  small  lots  may  reach  £600  to  £800 
($3,000  to  $4,000),  or  even  more,  per  ton. 


Scale 

lOO  200 


Fig.  187.     Stereogram  of  Ore-shoot  on  the  Pinto  Dyke  and  Pharmacist  Vein, 

Cripple  Creek  {Lindgrtn  . 


The  values  occur  in  irregular  ore-shoots  within  the  fissures. 
The  shoots  have  generally  a  greater  extension  vertically  than 
laterally.  They  are  ordinarily  either  vertical  or  pitch  steeply 
northward.  Few  ore-bodies  exceed  1,000  feet  in  length  or  depth. 
The  principal  productive  zone  extends  to  the  1,000-foot  level. 
Below  that  depth  the  ore  is  decidedly  less  in  quantity  rather  than 
lower  in  grade.  Little  evidence  of  secondary  enrichment  was 
found  by  Lindgren  and  Ransome  either  in  the  sulphide  zone  by 
downward  solutions  or  of  absolute  enrichment  in  the  oxidised 
zone  by  upward-moving  solutions,  the  final  conclusion  being  that 
in  both  zones  secondary  enrichment  was  practically  absent. 

The  principal  mines  of  the  district  are  the  C.  O.  D.  and  Gold 
King  in  Poverty  Gulch  ;  Anchoria-Leland,  Moon- Anchor,  Anaconda, 
on  Gold  Hill  ;  Doctor  Jackpot,  Work,  Mary  McKinney,  and  Elkton, 
in  Raven  and  Guyot  Hills  ;  El  Paso,  C.  K.  &  N.,  on  Beacon  Hill ;  Lost 
Dollar,    Modoc,   and  Union,  on  Bull    Hill  ;    Victor  and  Isabella, 


COLORADO. 


553 


between  Altman  and  Goldfield ;  Pinto  and  Pharmacist,  near 
Altman  ;  Findley  and  Shurtoff,  Hull  City,  Vindicator,  and  Golden 
Cycle,  all  in  the  neighbourhood  of  Bull  Cliff  on  the  Vindicator  lode 
system  ;    Portland  and  Stratton's   Independence   to   the   east   of 


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Fig.  188.     Section  through  Stratton's  Independence  Mine,  showing  relation  of  veins  to 
zone  of  granite-breccia  contact  (Lindgren). 

Battle  Mount  ;    and  finally,  Strong,  Granite,  Ajax,  and  Gold  Coin, 
on  Battle  Mount  (western  portion). 

It  is  clear  from  a  consideration  of  the  distribution  of  the  richer 
mines  that  the  richest  part  of  the  field  lies  in  the  neighbourhood 
of  Bull  Cliff  and  Independence,  or  in  other  words,  well  to  the  south- 
east side  of  the  ancient  vent.  The  ores  of  the  district  have  in  the 
past  nearly  all  been  carried  by  the  Cripple  Creek  Short  Line  to 
Colorado  City  to  be  chlorinated.      The  cyanide  process,   both  at 


554 


NORTH    AMERICA. 


Colorado  City  and  on  the  field  itself,  is  in  1908  rapidly  supplanting 
the  chlorination  process,  and  cyanide  will  probably  eventually 
oust  the  older  solvent.  In  1906  and  1907  the  Portland  was  the 
leading  producer  at  Cripple  Creek.  In  order  to  facilitate  work 
at  the  lower  levels  of  the  Cripple  Creek  mines,  ordinarily  subject 
to  considerable  flows  of  water,  a  low-level  tunnel  was  commenced 
at  the  end  of  1907  to  cut  the  lodes  of  the  field  2,000  feet  below 
Beacon  Hill  and  3,200  feet  below  Bull  Hill.  The  total  estimated 
length  of  the  tunnel  when  completed  will  be  3-|-  miles.'1 

The  following  table  shows  the  annual  yield  of  Cripple  Creek 
goldfield,  and  is  derived  from  the  reports  of  the  Director  of  the 
United  States  Mint  :— 


Year. 

Value. 

Year. 

Value. 

1891 

$449 

1900 

$13,073,539 

1892 

583,010 

1901 

17,261,579 

1893 

2,010,367 

1902 

16,912,783 

1894 

2,908,702 

1903 

12,967,338 

1895 

6,879,137 

1904 

14,499,529 

1896 

7,512,911 

1905 

15,724,344 

1897 

10,139,709 

1906 

14,253,245* 

1§98 

13,507,244 

1907 

13,148,152f 

1899 

15,658,254 

*  Min.  Res.,  U.S.  Geol.  Surv.,  1906,  p.  236. 
■\  Estimated. 

Gunnison  County. — At  the  present  time  Gunnison  County 
is  a  small  gold  producer,  the  value  of  the  gold  obtained  in  1905 
being  only  £5,772  ($28,156).  Little  is  known  of  the  geology  of 
the  country.  Some,  at  least,  of  the  silver-gold  veins  are  in  lime- 
stones that  are  intruded  by  Tertiary  volcanic  rocks. 

Ouray  County.- — Ouray  County,  next  to  the  south-west,  has, 
on  the  other  hand,  important  gold  veins  that  furnished  in  1905 
gold  to  the  value  of  £478,323  ($2,333,282).  This  is  the  most  northerly 
of  the  counties  of  the  San  Juan  group  (Ouray,  San  Miguel,  Dolores, 
San  Juan,  Hinsdale,  La  Plata,  and  Montezuma). 

The  eruptive  regions  of  Rosita  and  Silver  Cliff,  and  also  of 
Cripple  Creek,  may  be  considered  as  outlying  minor  eruptions 
of  the  same  character  as  the  great  flows,  tuffs,  and  agglomerates 
of  the  San  Juan  and  South  Mountains  to  the  south-west  of  Colorado. 
In  both  the  first-mentioned,  cases  the  actual  positions  of  the  ancient 


a  The  foregoing  account  of  the  Cripple  Creek  district  has  been  largely  derived  from 
the  already  classic  monograph  of  Lindgren  and  Ransome,  Prof.  Papsr  U.S.  Geol.  Surv., 
No.  54,  1906,  pp.  1-496.  Other  detailed  reports  on  the  field  are  Cross  and  Penrose,  16th 
Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  II,  1895,  p.  1  ;  Richard,  T.A.,  Trans.  Inst.  Min.  Met., 
VIII,  1900,  p.  49  ;  Id.,  Trans.  Amer.  Inst.  M.E.,  XXXIII,  1903,  p.  578  ;  Stevens,  E.  A., 
ib.,  XXXIII,  1903,  p.  686. 


Plate  XXX. 


Bassick  Hill  axi>  Mount  Tyndall,  from  the  South. 


Silveeton,  Colorado,  Looking  North. 
(U.S.  Geological  Survey.) 


COLORADO. 


555 


vents  may  be  located,  a  feature  impossible  in  the  San  Juan  region, 
where  the  volcanic  forces  possessed  much  greater  activity.  The 
general  age  of  these  eruptions  is  late  Eocene  or  early  Miocene. 


••Pal'- 


looouoo:. 


M 


SURFtOAt.  BOCKS 

PLEISTOCENE 

ALLUVIUM 

LAND-SLlOES 

SEDIMENTARY    FORMATIONS 

EOCENE? 

TELLURiOE  CONGLOMERATE 

UPPER  CARBONIFEROUS 
HERMOSA 


v.mp-- 


prh 


IGNEOUS  ROCKS 
EOCENE  AND  NEOCENE 
MONSONITE  PORPHYRY   / 
POTOSI  SERIES 


,/*        FAULT 


LODE-FISSURES 


MINERAL  DEPOSITS  OTHER 
O    THAN  *.OOES,  CHIEFLY  STOCKS 


V 'S*^>     SILVERTON  6ER1 


ES  Y      MINES  /No.haryd 


PROSPECTS 


htmMi.  tha  iwo. 


CAN  JUAN  SERIES 


6CALE   OP   MILES 


TU'sTRIKE   AND  DIP 
a     VERTICAL  LODES 


Fig.  189.     Geology  of  Camp  Bird  and  Neighbourhood  (Purington). 


556 


NORTH    AMERICA. 


The  Camp  Bird  mine  in  Imogene  Basin,  8  miles  from  Ouray, 
has  proved  one  of  the  most  productive  of  modern  gold  mines, 
producing  in  1905,  £446,007  ($2,175,645),  or  no  less  than  93  per 
cent,  of  the  total  yield  for  the  whole  Ouray  County.  Its  vein 
traverses  the  andesitic  breccias  and  tuffs  of  the  San  Juan  formation, 
that  overlie  Mesozoic  and  Palaeozoic  sedimentary  rocks  and 
Algonkian  quartzites.  The  San  Juan  formation  has  a  thickness  of 
some  2,500  feet  in  the  Canyon  Creek  area.  Its  tuffs  and  breccias 
are,  when  considered  broadly,  fairly  well  stratified."  They  are 
overlain,  to  the  east  of  the  Camp  Bird  mine,  by  the  great  Silverton 
series  of  massive  andesites,  rhyolitic  flow-breccias,  and  tuff-breccias, 


Fig.  189a.     Showing  structure  of  Vein-quartz,  Camp  Bird  Mine  (Ransome). 

Magnified  14  diameters;  black  areas,  fluorite ;  shaded  areas,  quartz  ;  cross-hatched  areas,  calcite  ; 

nicols  crossed. 


that  attain  a  thickness  of  4,000  to  5,000  feet.  Capping  the  mountain 
ranges  at  an  elevation  above  sea-level  of  13,000  feet  is  a  rhvolite, 
closely  akin  to  the  wide-spread  Potosi  rhyolite  of  the  south-east. 
Through  the  Silverton  series  small  stocks  of  orthoclase-porphyry 
are  intrusive. 

The  Camp  Bird  vein  follows  two  main  fissure  zones,  one  striking 
X.  87°  W.,  and  the  other  N.  72°  W.  A  minor  zone  strikes  N.  51°  W.  ; 
all  three  dip  towards  the  south.6      The  average  width  of  the  vein 


"  Cross,  Bull.  U.S.  Geol.  Surv.,  No.  182,  1901,  p.  31. 

6  Purington,  Trans.  Araer.  Inst,  M.E.,   XXXIII,  1903,  p.  510. 


Plate  XXXI. 


View  from  South  of  Ophir  Pass. 


Potosi  Peak. 
MOUNTAIN    SCENERY    IN    THE    VICINITY    OF    TELLURIDE,    COLORADO. 

(U.S.  Geological  Survey.) 


COLORADO.  557 

is  6  to  7  feet.  It  has  well-defined  walls.  The  principal  gangue 
mineral  is  white,  opaque,  generally  crystalline  quartz.  Open 
cavities  and  vughs  in  the  vein  are  numerous.  Calcite,  rhodonite, 
and  chlorite  are  also  vein  minerals.  The  chief  metallic  sulphide 
is  pyrite,  which  occurs  either  in  the  quartz  or  disseminated  through 
"  horses  "  of  country  within  the  lode.  Blende  is  rare.  Magnetite, 
a  very  unusual  associate  of  gold  (but  found  with  the  tellurides  of 
Kalgoorlie,  W.A.),  occurs  in  an  exceedingly  fine  state  of  division 
intimately  mixed  with  galena  in  the  white  quartz.  It  has  been 
detected  only  on  analysis,  but  nevertheless  appears  to  occur  in 
considerable  quantity,  the  cloudy  bands  ascribed  to  its  presence 
indicating,  as  a  rule,  a  high  gold  tenor.  Galena  and  chalcopyrite 
are  found,  the  latter  in  small  quantity.  The  gold  occurs  finely 
divided  and  scattered  through  the  quartz,  and  is  associated  generally 
with  galena  and  magnetite.  Its  fineness  is  740,  the  remainder  being 
silver.  The  ore-bodies  of  the  Camp  Bird,  as  of  most  gold  mines,  are 
found  in  shoots,  some  of  which  have  been  worked  from  the  surface 
to  a  depth  of  800  feet.  There  is  little  or  no  evidence  of  secondary 
enrichment  in  the  district.  The  Camp  Bird  mine  is  situated  about 
11,500  feet  above  sea-level  in  a  region  subject  to  snow-slides.  In 
1906  the  crushing-mill  was  almost  completely  wrecked  by  an 
avalanche  that  took  an  unexpected  course. 

Other  mining  districts  of  Ouray  County  are  Sneffels,  Red 
Mountain  and  Uncompahgre.  The  Sneffels  mines  are  also  in  the 
San  Juan  formation.  The  Red  Mountain  district  includes  the  well- 
known  Yankee  Girl  and  other  mines.  The  country  of  the  field  is  the 
Silverton  formation^  made  up  of  an  andesite  breccia  with  andesite 
flows,  all  being  cut  by  numerous  andesitic  dykes.  The  Yankee  Girl 
vein  was  located  in  1881.  The  conditions  under  which  the  ore 
occurred,  for  most  of  it  has  now  been  worked  out,  were  remarkable. 
It  was  found  in  several  cylindrical  or  elliptical  chimneys,  20  to  30 
feet  in  diameter,  in  the  breccia,  which  is  decomposed  in  the  immediate 
vicinity  of  the  ore-chimneys.  Emmons b  believed  that  here,  as  in 
the  Bassick  mine  already  described,  the  direction  of  the  chimney 
was  determined  by  intersecting  fissures.  Around  each  chimney 
is  an  envelope  of  quartz  that  is  impregnated  with  fine-grained 
pyrite.  The  ores  were  exceedingly  rich  in  silver,  one  car-load  of 
6  tons  carrying  5,300  ounces  silver  per  ton.  The  total  yield  of 
the  mine  is  said  to  have  been  some  £600,000  ($3,000,000). 

In  the  Uncompahgre  district  at  Ouray  the  American-Nettie 
is  the  chief   mine.      The    country    is    composed    of    sedimentary 

°  Ransome,  Bull.  U.S.  Geol.  Surv.,  No.  182,  1902,  p.  215. 
b  lb.,  p.  216. 


558 


NORTH    AMERICA. 


rocks  that  range  in  age  from  pre-Cambrian  to  Cretaceous,  are 
traversed  by  porphyry  dykes,  and  contain  intercalated  porphyry 
sheets.  Ores  occur  in  fissure- veins  or  as  replacement  deposits  of 
limestone  or  quartzites,  the  horizon  of  the  top  of  the  Dakota 
(Cretaceous)  quartzite  being  especially  affected." 


>  Pandora  /A  *      *~  (  7>  '-rr^Vi 


Fig.  190.    Geology  of  Telluride  and  Vicinity. 

1.  Rhyolite  and   andesite.     2.  San  Juan  Formation— andesitic  breccia.     3.  San  Miguel 

conglomerate.     4.  Jurassic  and  Cretaceous  shales  and  sandstones. 

San  Miguel  County.— To  the  south-west  of  Ouray  County  is 
San  Miguel  County.  Its  chief  town  is  Telluride,  which  is  also  the 
locality  of  the  most  productive  mining  operations.  The  mines  near 
Telluride  in  1905  produced  more  than  £300,000  ($1,574,607)  gold, 
or  about  90  per  cent,  of  the  total  for  the  county.  The  average 
value  of  the  ore  produced  was  £1.  19s.  3d.  ($9.58).     The  veins  are 


"  Irving,  Bull.  U.S.  Geol.  Surv.,  Xo.  260,  1905,  p.  5G. 


- 


COLORADO. 


559 


strong,  well-defined  bodies  that,  like  the  Camp  Bird  vein,  traverse 
the  San  Juan  tuffs  and  breccias.  The  three  leading  mines  are  the 
Liberty  Bell,  Smuggler-Union,  and  Tomboy.  The  first-named  was 
discovered  in  1876,  but  only  the  richer  ores  could  be  worked  until 
1891." 

The  San  Juan  formation  is  here  a  bluish-grey  andesitic  breccia, 
varying  in  thickness  from  2,000  to  3,000  feet.  The  veins  of  the 
district  are  remarkable  for  their  strength,  reaching  often  5  to  6  feet 
in  width.  The  Liberty  Bell  lode  itself  ranges  from  3  to  8  feet, 
and   carries  well-defined  and  sometimes  smooth  and  slickensided 


i0  feet 


Fig.   191.     Diagrammatic  section  through  Enterprise  Blanket,  Rico,  showing  gypsum 

(on  right)  [Ransome). 

walls.  The  lode  includes  often  large  "  horses  "  of  country.  Its 
filling  is  quartz  together  with  a  barren  siliceous  replacement  of 
slates  that  are  interspersed  with  bands  of  clay.  The  quartz  layers 
are  sometimes  hard  and  dense.  Free-gold  occurs  in  the  unaltered 
quartz,  and  is  also  intimately  mixed  with  the  pyrite.  The  lode  is 
traversed  by  numerous  veinlets  of  quartz  and  of  calcite  of 
secondary  and  contemporaneous  origin.  Tellurium  is  absent.  Of 
the  total  value  of  the  ore,  two-thirds  is  represented  by  gold  and 
one-third  by  silver.6  To  the  end  of  1897  some  £5,000,000  gold 
had  been  produced  from  this  mine.  In  the  cases  of  the  Smuggler 
and  Tomboy  veins  it  is  evident  that  the  lodes  are  continuous  from 
the  San  Juan  breccia  upwards  through  the  overlying  andesite  and 
rhyolite  flows.  Certain  veins  in  the  district  also  pass  into  the 
underlying  San  Miguel  conglomerate,  where  they  become  somewhat 
more  brecciated  and  more  irregular  in  continuity.  The  lodes  of 
the  Telluride  district-  are  of  unusual  extension  in  strike,  the 
Smuggler  vein,  for  example,  having  been  traced  for  more  than  two 
miles. 


«  Winslow,  Trans.  Amer.  Inst.  M.E.,  XXIX,  1899,  p.  291. 

b  Purington,  18th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  Ill,  1896,  p.  751  ;    Id.,  U.S.  Geol. 
Atlas,  Fol.  57,  1899,  p.  15. 


560  NORTH    AMERICA. 

Dolores  County. — The  yield  from  Dolores  County  is  at  the 
present  time  very  small.  The  famous  Rico  district,  which  produced 
mainly  silver,  is  now  almost  deserted.™  Rico  itself,  however, 
yielded  comparatively  little  gold,  and  the  1,660  ounces  gold 
recorded  as  having  been  produced  in  1905  came  from  isolated  and 
outlying  mines,  as  the  Emma  at  Dunton,  15  miles  north-west 
of  Rico.  The  general  range  of  the  Enterprise  ores,  the  richest  at 
Rico,  has  been  from  0-2  to  1«0  ounce  gold  and  100  to  200  ounces 
silver  per  ton,  with  lead  to  10  per  cent.,  and  zinc  to  15  per  cent. 
The  country  of  the  Enterprise  mine  is  formed  by  the  sandstones, 
shales,  and  limestones  of  the  Hermosa  (Lower  Carboniferous) 
formation.  The  total  thickness  of  the  beds  is  some  800  feet  ;  the 
Enterprise  ore-bodies  occur  midway  between  the  top  and  bottom. 
The  ore  forms  a  so-called  "  blanket,"  consisting  for  the  most  part 
of  unconsolidated  breccia,  resting,  in  the  case  of  the  Enterprise, 
Newman  Hill,  everywhere  on  a  very  thin  bed  ranging  in  thickness 
only  to  2  inches  of  limestone,  below  which  is  found  5  to  6  feet  of 
dark  shales,  alternating  with  thin  lenses  of  limestone.  The 
"  blanket  "  averages  6  feet  in  thickness  but  may  reach  20  feet. 
It  is  invariably  overlain  by  a  fissile  black  shale.  It  dips  with  the 
enclosing  beds,  and  is  made  up  of  brecciated  and  comminuted  shale 
in  the  upper  portion,  and  of  fine  laminated  material  (pulverulent 
dolomite  and  celestite)  in  the  lower  portion  that  rests  directly 
on  the  limestone.  Wherever  ore  occurs  it  is  usually  as  a  replacement 
of  the  limestone.  Ransome  &  concluded  that  the  peculiar  "  blanket " 
bed  is  the  remains  of  a  once  continuous  bed  of  gypsum  that  formerly 
occupied  the  blanket  horizon,  and  that  has  been  largely  removed  by 
solution.  The  residue  has  been  subsequently  silicified  and  impregnated 
with  ore,  more  particularly  in  the  lower  finer  portions  of  the  blanket. 
The  ore  is  galena,  blende,  and  rich  silver  sulphides.  Most  of  the 
so-called  contact-ore  has  now  been  worked  out.  The  deposition 
of  the  Rico  ores  is  probably  to  be  considered  an  after-effect  of  later 
Tertiary  igneous  intrusions. 

La  Plata  County. — In  La  Plata  County  the  important  veins 
fall  into  two  divisions  :  (a)  telluride-gold  veins  ;  (b)  simple  gold 
veins.  The  principal  mining  field  is  Oro  Fino  (California)  at  the 
head  of  Junction  Creek  on  the  eastern  slope  of  the  La  Plata 
Mountains.0     The  veins  lie  in  red  calcareous  clays,  red  sandstones, 

a  Rickard  T.A.,  Trans.  Amer.  Inst,  M.E.,  XXVI,  1897,  p.  90G ;  Ransome,  22nd 
Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  II,  1901,  p.  237  ;  Cross  &  Spencer,  21st  Ann.  Rep.  U.S. 
Geol.  Surv.,  Pt.  II,  1900,  p.  7. 

b  Loc.  cit.  sup.,  p.  278. 

c  Purington,  Folio  60,  U.S.  Geol.  Surv.  Atlas,  1899,  p.  13  ;  Emmons,  W.  H.,  Bull, 
260,  U.S.  Geol.  Surv.,  1905,  p.  121. 


COLORADO.  561 

and  conglomerates.  They  are  collectively  known  as  the  "  Red 
Beds,"  and  are  of  probable  Permian  age.  They  are  much  intruded 
by  diorite-  or  monzonite-porphyries  that  occur  both  as  dykes  and 
sills.  These  are  assumed  to  be  of  Tertiary  age.  The  sandstones, 
usually  red  and  friable,  are,  in  the  neighbourhood  of  the  ore-bodies, 
highly  silicified.  Along  certain  nearly  vertical  planes  the  rocks 
have  been  fractured  and  fissured,  and  near  these  fissures  both  the 
sedimentary  rocks  and  the  porphyry  have  been  impregnated  with 
ore.  The  ore-deposits  occur  both  as  contact  deposits  and  as  silicified 
replacement  bands  along  fissure  zones  near  porphyry  contacts. 
Often  the  ore  appears  to  be  a  replacement  of  the  porphyry  and 
sometimes  also,  but  less  frequently,  of  the  sedimentary  beds.  The 
gangue  is  quartz,  kaolinite,  hydrous  silica,  and  sericite.  The  ore- 
minerals  are  tellurides  of  gold  and  silver  (sylvanite,  petzite,  and 
probably  calaverite),  native  gold,  native  mercury,  amalgam, 
freibergite,  tennantite,  stephanite,  pyrite,  marcasite,  chalcopyrite, 
galena,  blende,  realgar,  magnetite,  and  possibly  cinnabar.  The 
principal  ores  are,  however,  the  high-grade  tellurides  and  free  gold. 
The  production  of  gold  in  1905  was  £51,647  ($251,940).  The  chief 
mines  are  the  Neglected  and  the  May  Day. 

San  Juan  County. — The  San  Juan  goldfields  on  the  southern 
slope  of  the  San  Juan  mountains  are  among  the  richest  in  Colorado. 
Their  yield  has  been  of  late  more  than  a  million  dollars  per 
annum.  Their  total  production  to  1900  was  some  £4,800,000 
($24,000,000).  The  mines  extend  from  Silverton  north-east  up 
both  sides  of  the  Animas  Valley  to  and  beyond  Animas  Forks. 
Minor  pyritous  gold-quartz  veins,  containing  small  pockets  of  free 
gold,  occur  south-south-west  of  Silverton  in  Deer  Park  Creek, 
cutting  schists  and  granites  and  sometimes  the  overlying  San  Juan 
tuffs. 

The  important  lodes  of  Silver  (Arrastra)  Lake,  3|  miles  south- 
east of  Silverton,  are  heavily  mineralised  with  galena,  blende,  and 
chalcopyrite,  and  with  minor  quantities  of  pyrite  and  tetrahedrite. 
Thej^  lie  in  the  Burns  latite  division  of  the  Silverton  series,  already 
noted  as  overlying  the  San  Juan  tuffs.  The  ore  is,  as  a  rule,  low-grade, 
and  requires  concentration.  It  is  worth  from  32s.  to  £3  ($8.00 
to  $15.00)  per  ton.  Free  gold  is  rare,  but  the  tenor  in  gold  may 
nevertheless  rise  to  2  or  3  ounces  per  ton.  About  one-half  the  value 
of  the  output  of  the  Silver  Lake  district  is  gold,  the  remainder  being 
silver,  lead,  and  copper. 

In  Sunnyside  Basin  and  at  the  head  of  Placer  Gulch,  6^  miles 
north-north-east  of  Silverton,  the  ores  are  low-grade  bodies  with 
occasional  bunches  of  rich  ore  (ranging  to  74  ounces  per  ton).  The 
principal  mine  of  this  area,  and  indeed   of   the  whole   San  Juan 

Ml 


562  NORTH    AMERICA. 

country,  has  been  the  Gold  King.  The  Gold  Prince  and  Sunnyside 
are  also  important  producers.  The  Poughkeepsie  Gulch  veins, 
in  the  extreme  north  of  the  county,  are  similar  to  those  of  the 
Gold  King  and  Sunnyside.  They  carry  galena,  sphalerite,  and 
chalcopyrite,  which  are  invariably  associated  with  rhodonite.  The 
ores  run  generally  in  pay-shoots  within  the  lodes.  Oxidation  of 
the  ores  at  the  surface  is  unimportant  at  these  high  altitudes  of 
from  11,000  to  12,000  feet." 

The  veins  of  the  two  northern  districts  of  San  Juan  County 
are,  like  those  of  Silver  Lake  Basin,  mainly  in  the  Burns  horn- 
blende-latite  flows,  but  they  may  pass  upwards  into,  or  may  occur 
entirely  in,  the  overlying  pyroxenic  andesite  flows,  both  rocks 
being  members  of  the  Silverton  series. 

Hinsdale  County The  gold  production  of   Hinsdale  County 

is  small.  Most  of  its  ore-deposits  are  situated  a  few  miles  west 
of  Lake  City.  The  rocks  containing  the  veins  are  rhyolitic  and 
andesitic  breccias  with  intrusive  andesites,  diabase,  and  latite. 
Gold-bearing  veins  are  not  numerous.  The  Golden  Fleece  is 
the  most  prominent.  This  mine  produced  to  1905  about 
£280,000  ($1,400,000)  gold.  The  vein  lies  in  tuffs  and  breccias 
intercalated  with  an  andesitic  flow-breccia,  through  which  a 
diabase  dyke  is  intrusive.  The  chief  ore  present  is  the  gold- 
telluride,  petzite.& 

Mineral  County. — In  Mineral  County  the  principal  centres 
are  Creede,  Amethyst,  and  Teller,  in  the  north  of  the  county.  The 
lodes  are  fissure  veins  in  andesite  flows.  Their  gold  value  is  subor- 
dinate, the  metals  recovered  being,  in  order  of  decreasing  value, 
silver,  lead,  zinc,  and  gold.  The  ores  at  Creede  contain  0-1  to  0-2 
ounce  gold,  1  to  3  ounces  silver,  7  to  8  per  cent,  lead,  and  4  to  6 
per  cent,  zinc,  the  total  average  value  being  36s.  to  40s.  ($9.00  to 
$10.00)  per  ton.  The  veins  are  strong  quartz-lodes,  often  well 
banded,  and  carrying  a  comb  of  amethystine  quartz  crystals  in 
the  centre.  The  deeper  mines  are  now  1,500  to  1,600  feet  below 
the  surface.  A  remarkable  feature  in  Creede  is  the  increase  of  the 
gold  values  in  depth.0  This  is,  however,  characteristic  of  many 
of  the  San  Juan  lodes,^  and  arises,  probably,  from  an  impoverish- 
ment of  the  outcrop.     Such  an  impoverishment  is  always  possible 

"  Ransome,  Fol.  120,  U.S.  Geol.  Surv.  Atlas,  1905,  p.  33  ;  Id.,  Bull.  182,  U.S.  Geol. 
Surv.,   1901,  p.  87. 

6  Irving,  Bull.  260,  U.S.  Geol.  Surv.,  1905,  p.  83. 

r  Lakes.  Mines  and  Minerals,  XXIII,  1903,  p.  433. 

™  Purington,  in  litt. 


COLORADO.  563 

when  the  contained  gold  is  very  fine.  As  an  analogous  example  may 
be  cited  the  variations  in  the  vertical  tenor  of  the  quartz  of  the 
Waihi  mine,  New  Zealand,  where  the  gold  is  also  exceedingly  finely 
divided. 

The  total  gold  yield  of  Colorado  between  the  years  of  1858  to 
1900  is  estimated  by  Lindgren«  at  £51,475,500  ($251,100,000). 
During  the  present  century  the  yield  has  been  :  — 


Year. 

Value,  Dollars. 

Value,  Sterling. 

1901 

#27,693,500 

£5,677,167 

1902 

28.468.700 

5,836,083 

1903 

22,540,100 

4,620,720 

1904 

24,463,322 

5,014,981 

1905 

25,701,100 

5,268,725 

1906 

23,210,629 

4,758,178 

1907 

20,888,883 

4,182,222 

Grand  Total  to  1907. 

$424,066,234 

£86,833,576 

UTAH. 

Few  veins  in  Utah  are  worked  exclusively  for  their  gold  content, 
and  the  greater  part  of  the  gold  yield  of  the  State  comes  from  copper- 
gold  or  lead-silver-gold  veins.  Of  the  former  those  of  Tintic,  Juab 
County,  furnished  in  1905  almost  exactly  one-half  the  gold  yield 
of  the  State.  The  principal  lead-silver-gold  districts  are  Bingham 
and  Park  City.  The  placers  of  Utah  have  never  been  important, 
and  only  one,  viz.,  at  Bingham  Canyon,  Salt  Lake  Count}^,  has  been 
extensively  worked.  The  yield  of  alluvial  gold  from  this  deposit 
is  estimated  by  Lindgren6  at  some  £200,000  ($1,000,000).  Post- 
Miocene  propylitic  gold-quartz  veins  do  occur  in  Utah,  but  are 
not  common  ;  the  preponderating  ore-deposits  are  irregular  masses 
at  contacts  of  sheets  and  dykes  of  porphyry  with  sedimentary  rocks. 
They  are,  as  explained  above,  mainly  lead,  copper,  and  silver  ores 
with  comparatively  insignificant  amounts  of  gold.  Their  age  is 
believed  to  be  Cretaceous. 

Mercur — Of  purely  gold  deposits  the  most  important  is  at 
Mercur,  in  the  Oquirrh  Mountains,  south  of  Great  Salt  Lake,  and 
west  of  Utah  Lake.  In  this  region  the  discovery  of  silver  preceded 
that  of  gold.  The  geology  of  Mercur  district  is  simple. 
The  prevailing  rock  is  a  Lower  Carboniferous  limestone,  through 
and    into    which    quartz-porphyry    is     intrusive.       The     igneous 


n  Trans.  Amer.  Inst.  M.E.,  XXXIII,  1903,  p.  818. 
6  lb.,  p.  836. 


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UTAH.  565 

rock  occurs  not  only  as  dykes  and  stocks,  but  also  as  thin  sheets, 
intruded  parallel  to  the  stratification  of  the  limestone.  Beneath 
the  quartz-porphyry  sheets  much  of  the  ore-deposition  has  taken 
place/4  All  that  may  be  said  with  certainty  regarding  the  age  of  the 
intrusive  rocks  is  that  they  are  older  than  Pleistocene  and  younger 
then  Carboniferous.  They  are,  moreover,  in  all  probability,  post- 
Jurassic.  The  characteristic  feature  of  the  Mercur  field  is  the 
presence,  in  a  massive  limestone,  of  two  ore-bearing  beds  about 
100  feet  apart,  the  lower  (the  Silver  Ledge)  carrying  silver,  and  the 
upper  (the  Gold  Ledge)  containing  gold  with  little  or  no  silver. 
Both  occur  at  horizons  near  the  middle  of  the  limestone  series.  The 
Silver  Ledge  consisting  of  quartzite,  or  dark  silicified  limestone,  is 
porous  and  brecciated,  and  in  addition  to  silver  carries  a  little 
copper  and  antimony,  but  no  gold.  The  upper  bed,  or  Gold  Ledge, 
is  a  decomposed,  sometimes  bleached,  sometimes  red  or  yellow 
limestone  and  shale,  with  a  little  realgar  and  cinnabar  in  addition 
to  gold.  It  was  concluded  by  Spurr,  to  whom  we  are  indebted 
for  most  of  the  geological  information  concerning  the  Mercur  camp, 
that  there  had  been  two  distinct  and  well-separated  periods  of 
mineralisation,  the  minerals  of  the  Silver  Ledge  having  been  the 
earlier  deposited. h  In  each  period  the  minerals  constituting  the 
ore  were  precipitated  along  the  lower  plane  of  contact  of  a  porphyry 
sheet  with  the  limestone.  The  vein  minerals  of  the  Silver  Ledge 
are  silica,  barytes,  and  stibnite,  with  copper  and  silver  sulphides. 
Through  the  whole  of  the  impregnated  zone  the  limestone  has  been 
entirely  replaced  by  silica.  The  characteristic  minerals  occurring 
with  gold  in  the  Gold  Ledge  are  barytes,  calcite,  realgar,  cinnabar, 
and  pyrite.  There  are  grounds  for  the  belief  that  the  gold  was 
originally  deposited  as  a  telluride.  At  the  horizon  of  the  Gold  Ledge, 
ore-bodies  are  found  mainly  at  the  intersection  of  certain  zones  of 
north-east — south-west,  nearly  vertical  Assuring  with  the  lower 
contact-plane  of  the  porphyry  sheet.  The  ore-bodies  may  attain  a 
thickness  of  20  feet  or  more,  thinning  away  to  nothing  at  some 
distance  on  either  side  of  the  fissure-zones.  The  mineralisation 
along  the  contact  zone  is  therefore  not  continuous.  Both  sulphide 
and  oxidised  ores  occur.  The  tenor  of  the  ore  is  never  very  high, 
rarely  exceeding  two  or  three  ounces  per  ton  and  averaging 
much  less. 

Tintic. — The  Tintic  region  lies  south  of  Mercur  in  Juab  County. 
It  is  on  the  southward  continuation  of   the  Oquirrh  mountains, 

a  Emmons,  S.  F.,  16th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  II,  1895,  p.  364. 
"  Spurr,  ib.,  p.  367. 


566  NORTH    AMERICA. 

and  is  one  of  the  oldest  mining  camps  in  Utah,  having  been  estab- 
lished towards  the  end  of  1869.  Its  early  yield  is  not  known  with 
certainty,  but  from  1880  to  1896  the  district  had  produced  201,967 
ounces  gold  and  28,308,092  ounces  silver/'  As  obtains  further 
north  at  Mercur,  the  Tintic  rocks  are  Carboniferous  sedimentaries 
associated  with  intrusive  igneous  rocks.  The  Carboniferous  rocks 
are  quartzites  and  limestones,  the  ore-bodies,  as  a  rule,  occurring  in 
the  latter.  These  sedimentaries  are  bent  into  a  simple  synclinal  fold 
along  the  Tintic  mountains.  The  igneous  rocks  include  monzonite, 
andesite,  quartz-porphyry,  rhyolite,  and  basalt  of  an  age  contem- 
poraneous with  those  in  the  Oquirrh  mountains.  The  gold  deposits 
of  the  Tintic  region  are  confined  to  the  sedimentary  rocks,  and, 
as  a  rule,  follow  north  and  south  fissures  in  the  limestone.  The 
smaller  ore-bodies  are  generally  the  richer,  and  enrichments  occur 
most  frequently  at  the  intersection  of  fissures,  forming  irregular 
shoots,  pockets,  pipes,  and  chimneys.  Free  gold  is  rarely  seen, 
except  in  stopes  near  the  surface.  The  average  proportion  of  silver 
to  gold  in  the  ores  is  400  to  1,  but  it  varies  considerably.  The 
general  tenor  of  the  ore,  reckoned  from  the  total  output  to  1899, 

was  :  — 

Gold      0-1356  ounces  per  ton. 

Silver 524400       „ 

Copper 11-2000  pounds 

Lead      270-0000       „ 

The  deepest  workings  at  Tintic  in  1908  had  reached  2,300  feet 
(Mammoth  mine),  and  at  that  depth  showed  no  appreciable 
impoverishment. 

Park  City.— The  deposits  of  the  famous  Park  City  district, 
south-east  of  Salt  Lake  City,  are  mainly  argentiferous  with  minor 
quantities  of  copper  and  gold.  Park  City  has  been  the  most  pro- 
ductive silver  camp  in  Utah.  The  gold  ores  here,  as  at  Tintic, 
occur  in  irregular  masses,  pockets,  and  shoots  in  metamorphic 
limestones  adjacent  to  igneous  intrusions.  The  highest  gold  values, 
however,  appear  to  be  associated  with  certain  fissures  in  quartzites.6 

Gold    Hill In   Piute   County   the    only   region   of    present 

importance  is  the  Gold  Hill,  where  the  Annie  Laurie,  the  principal 
mine,  was  opened  up  only  as  recently  as  1900,  though  the  veins 
and  placers  of  Marysvale  and  Bullion  Creek  in  the  immediate 
neighbourhood  had  long  been  known.  From  1900  to  1905  the  Annie 
Laurie  mine   had  produced  perhaps  £420,000  ($2,100,000)/       Its 

"  Tower  and  Smith,  G.  O.,  19th  Ann.  Rep.  U.S.  Geol.  Surv.,  1899,  Pt.  Ill,  p.  615. 
/;  Boutwell,  Bull.  U.S.  Geol.  Surv.,  No.  213.  1903,  p.  38  ;  Id.,ib.,  No.  225, 1904,  p.  141. 
'"  Lindgren,  Bull.  U.S.  Geol.  Surv.,  No.  285,  1906.  p.  87. 


UTAH. 


567 


ore-deposits  occur  in  well-defined  quartz  veins  in  a  decomposed 
rock,  probably  an  original  dacite.  Great  masses  of  rhyolite  and 
rhyolite-tuffs  are  found  to  the  north,  but  contain  no  veins  of  economic 
importance.  Dioritic  dykes  are  known,  but  appear  to  have  exercised 
no  influence  on  ore-deposition.  The  quartz  is  white  and  friable 
and  is  often  associated  with  calcite.  The  average  value  of  the  ore 
is  29s.  to  33s.  ($7.00  to  $8.00)  per  ton.  The  average  bullion  is  250 
fine  in  gold.  Lindgren  draws  attention  to  the  similarity  of  the 
Annie  Laurie  mine  in  country,  ore,  and  structure,  to  the  famous 
Waihi  mine  in  New  Zealand,  and  to  the  De  Lamar  mine  in  southern 
Idaho. 

The  total  production  of  gold  from  Utah  from  the  'sixties  to 
1900  is  estimated  at  £5,535,000  ($27,000,000).  Later  years  have 
given  :  — 


Year. 

Value,  Dollars. 

Value,  Sterling. 

1901 
1902 
1903 
1904 
1905 
1906 
1907 

$  3,690,200 
3,594,500 
3,697,400 
4,189,292 
5,140,900 
5,218,386 
4,654,930* 

£756,491 
736,872 
757,967 
858,804 
1,053,884 
1,069,769 
954,260 

Grand  Total  to) 
end  of  1907..) 

$57,185,608 

£11,723,047 

*  Estimated. 


TEXAS. 

The  gold  yield  of  Texas  is  trifling.  In  1905  only  12  ounces 
fine  gold  were  produced,  all  of  which  appears  to  have  come  from 
the  Shafter  mine  in  Presidio  County,  on  the  Mexican  frontier.  No 
placer  deposits  are  worked. 


NEW  MEXICO. 

The  mineral  belt  of  New  Mexico  stretches  from  north-east 
to  south-west  diagonally  across  the  territory.  It  therefore  lies  as 
a  broad  band  on  both  sides  of  the  Rio  Grande  (Rio  Bravo),  but  leaves 
that  river  in  Sierra  County,  and  passes,  still  striking  south-west, 
into  Grant  County.  Along  this  belt  the  mines  are  small  and  widely 
scattered.     The  fullest  account  given  of  the  auriferous  resources  of 


568  NORTH    AMERICA. 

New  Mexico  is  that  by  Lindgren  and  Graton."  The  northern 
portion  of  the  central  mountain  belt  of  New  Mexico  is  composed 
of  pre-Cambrian  crystalline  rocks,  mainly  red  and  grey  gneisses 
and  granites,  quartz-sericite-schist,  and  amphibolite-schist.  The 
last-mentioned,  together  with  chlorite-schists,  both  apparently 
derived  from  basic  intrusives  into  the  original  granite,  carry  the  pre- 
Cambrian  ore-deposits.  These  are  found  in  the  northern  counties  of 
Rio  Arriba,  Taos,  and  Santa  Fe,  and  are  for  the  most  part  pyritous 
with  low  tenors  in  gold  and  silver — perhaps  3  dwts.  of  the  former 
and  3  ounces  of  the  latter  per  ton.  They  are,  therefore,  of  little 
economic  importance.  In  general  relations  they  present  some 
analogies  with  the  pre-Cambrian  metalliferous  rocks  of  Encamp- 
ment,  Wyoming,  and  of  the  Southern  Appalachian  States, 

Post-Cretaceous  ore-deposits,  on  the  other  hand,  furnish  the 
major  portion  of  the  mineral  wealth  of  New  Mexico,  the  thick 
Palaeozoic  and  Mesozoic  sediments  that  intervene  in  geological 
time  between  the  pre-Cambrian  and  the  post-Cretaceous,  being 
generally  barren.  Post-Cretaceous  ore-deposition  took  place  at 
two  well-defined  and  widely  separated  periods,  one  at  the  beginning 
and  the  other  at  the  end  of  the  Tertiary  period.  The  older  is  directly 
connected  with  great  intrusive  masses  of  acidic  porphyries  and 
granitic  rocks,  and  is  represented  by  contact-metamorphic 
deposits,  fissure  veins,  and  siliceous  replacements  in  limestone. 
The  Elizabethtown  (Colfax  County)  ore-bodies  furnish  an 
example  of  deposition  during  this  period.  They  occur  as  contact- 
deposits  on  the  margin  of  a  great  porphyry  stock  intrusive  through 
Carboniferous  and  Cretaceous  strata,  and  carry  chalcopyrite  and 
gold.  Numerous  small  auriferous  veins  of  later  development  are 
found  cutting  through  the  porphyry,  the  contact-deposits,  and  the 
adjacent  Cretaceous  rocks.  The  Ortiz  and  San  Pedro  mountains, 
Santa  Fe  County,  are  porphyritic  laccoliths  in  Cretaceous  and 
older  rocks.  On  the  southern  contact  line  of  the  Ortiz  laccolith 
with  calcareous  Cretaceous  strata,  low-grade  contact-metamorphic 
deposits  occur  and  contain  garnet  and  chalcopyrite,  the  latter 
carrying  a  little  gold.  A  system  of  narrow  auriferous  quartz  veins 
is  developed  here,  in  the  same  fashion  as  at  Elizabethtown.  On 
one  of  these  gold-quartz  veins  a  celebrated  mine,  the  Ortiz,  was 
opened  up.  At  Jarilla  a  porphyry  laccolith  has  domed  the  Carboni- 
ferous limestones  and  has  produced  auriferous  contact-deposits 
associated  with  garnet,  epidote,  and  haematite.  In  the  porphyry 
mass  and  extending  out  into  the  enclosing  sedimentary  rocks  are 
gold  and  gold-copper  veins.  The  granite  of  the  Organ  mountains, 
which  lie  immediately  to  the  north  of  El  Paso,  in  Texas,  is  traversed 


a  Ba.  .     .s.  ( ;,.«,'.  Surv.,  No.  285,  1906.  p.  74. 


NEW    MEXICO.  569 

by  an  east  and  west  system  of  fissures,  now  filled  with  auriferous 
and,  sometimes,  argentiferous  quartz.  At  the  well-known  camp  of 
Pinos  Altos,  in  the  north  of  Grant  County,  narrow  fissures  carrying 
zinc  and  copper-ores  occur  in  a  limestone  that  has  been  disturbed  by 
intrusive  porphyry.  In  the  porphyry  itself,  gold-copper  veins  occur 
with  minor  amounts  of  silver,  lead,  and  zinc.  It  will  thus  be 
apparent  that  gold-quartz  veins  nearly  always  accompany  the 
contact-deposits  of  New  Mexico.  The  association  is  explained 
by  Lindgrena  on  the  assumption  that  the  baser  sulphides  have 
separated  out  in  the  earlier  stages  of  segregation  and  have  been 
deposited  at  the  boundaries  of  the  porphyry  stocks,  while  the 
gold-quartz  veins  cutting  as  they  do  alike  through  porphyry, 
contact-deposit,  and  sedimentary  rock,  are  of  a  much  later  date. 
The  auriferous  veins  of  this  period  are,  on  the  whole,  regular,  and 
show  little  or  no  brecciation.  Their  gangue  filling  is  quartz,  which 
often  shows  ribbon  or  comb-structure.  These  veins  are  the  source 
of  the  richer  placers  of  the  territory. 

Gold-pyrite  fissure  veins  in  late  Tertiary  andesitic  lavas  are 
known  at  Red  River,  Taos  County  ;  Cochiti,  Sandoval  County  ; 
Rosedale  (in  rhyolite),  Socorro  County  ;  and  at  Chloride,  Phillips- 
burg,  Grafton,  and  Hillsboro',  Sierra  County.  Perhaps  the  most 
important  veins  of  this  type  are  those  of  the  Mogollon  mountains, 
in  south-west  Socorro  County.  These  are  brecciated  fissure  deposits 
of  large  size.  Their  gangue  is  quartz  and  calcite,  which  also  have 
replaced  much  of  the  brecciated  matter  within  the  lodes.  The 
valuable  metals  are  found  as  finely  divided  gold  and  as  argentiferous 
sulphides.  Auriferous  deposition  appears  to  have  persisted  in 
New  Mexico  almost  down  to  the  present  time.  An  interesting 
example  is  adduced  by  Lindgren  and  Graton.^  At  Ojo  Caliente, 
Rio  Arriba  County,  a  small  silver-gold  vein  appears  to  be  directly 
connected  with  hot-spring  tufaceous  deposits  that  are  indeed  so 
recent  as  to  have  escaped  serious  modification  by  erosion.  Fine- 
grained, almost  chalcedonic  quartz  is  characteristic  of  many  of 
the  late  Tertiary  veins,  as  also  are  barytes  and  fluorite.  The  vein- 
walls  are  usually  brecciated,  and  the  veins  themselves  have  been 
formed  very  close  to  the  present  surface,  thus  differing  materially 
from  the  older  Tertiary  veins,  which  lie  in  deeply  dissected  regions. 

The  output  of  gold  from  New  Mexico  has  increased  considerably 
of  late  years,  mainly  owing  to  large  increase  in  the  production 
of  auriferous  copper,  lead,  and  zinc  ores,  in  which  the  gold  may 
generally  be  regarded  as  a  by-product.  Gold-mining  in  the  territory 

0  Loc.  cit.  sup.,  p.  84. 
"  Loc.  cit.  sup.,  p.  85. 


57<) 


NORTH    AMERICA. 


is  greatly  hindered  by  the  smallness  of  its  mining  camps  and  by 
their  wide  separation,  entailing  a  consequent  lack  of  transport 
facilities. 

Placer-mining  is  an  old-established  industry.  Alluvial  gold  is 
said  to  have  been  worked  by  the  Indians  at  San  Pedro,  Santa  Fe 
County,  before  Spanish  occupation,  but  the  amount  thus  recovered 
was  probably  insignificant.  The  gravels  are  certainly  among  the 
richest  now  known  within  the  United  States,  and  they  are  also  widely 
distributed.  Lack  of  water  has,  however,  been  the  great  factor 
in  hindering  the  development  of  placer-mines.  Dredging  has  been 
resorted  to  in  the  west  of  Colfax  County,  where  the  streams  flowing 
from  the  Elizabethtown  porphyry  stock  are  nearly  all  auriferous. 
The  Apache  Canyon,  Sierra  County,  has  also  furnished  a  considerable 
quantity  of  alluvial  gold. 

The  total  gold  production  of  New  Mexico  from  1860  to  1900 
inclusive  is  estimated  by  Lindgren  at  £3,608,000  ($17,600,000). 
Since  the  latter  year  the  annual  gold  yield  has  been  :  — 


Year. 

Value,  Dollars. 

Value,  Sterling. 

1901 
1902 
1903 
1904 
1905 
1906 
1907 

$688,400 
531,000 
244.600 
381,930 
265,800 
293,019 
249,569* 

£141,122 

108,855 
50,143 
78,295 
54,489 
60,069 
51.161* 

Grand  Total  to  end 
of  1907 

$20,254,318 

£4,152,134 

*  Estimated. 


MONTANA. 

In  its  early  yield  of  placer-gold  Montana  was  second  only  to 
California.  Its  most  famous  placer  deposits  were  those  of  Bannack 
and  of  Alder  Gulch,  Virginia.  The  latter  are  reported  to  have 
produced  in  the  early  'sixties  some  6,000,000  sterling  ($30,000,000). 
After  the  Alder  Gulch  deposits  the  rich  placers  near  Helena  were 
discovered  and  worked. 

The  western  part  of  Montana  is  considered  by  Lindgren" 
to  form  part  of  the  great  Idaho  uplift.  It  is  characterised  by  the 
presence  of  great  intrusive  masses  of  granitic  and  dioritic  rocks  of 

a  Trans.  Araer.  Inst.  M.E.,  XXXIII,  1903,  p.  825. 


MONTANA.  571 

apparently  later  age  than  those  of  California,  Oregon,  and  Idaho. 
The  Montana  intrusives  are  indeed  relegated  by  Weed  to  a  late 
Cretaceous  or  even  an  early  Tertiary  age.  The  auriferous  veins 
of  Montana  show  marked  analogies  with  those  of  the  Sierra  Nevada, 
but  there  are  at  the  same  time  considerable  variations  from  the 
Calif  ornian  type,  and  normal  gold-quartz  veins  of  the  latter  type 
are  rare.  Gold-silver  veins  as  that  of  the  Drumlummon,  Marysville, 
are  more  common.  Much  of  the  gold  product  of  Montana  is  obtained 
as  a  by-product  from  the  smelters,  and  more  especially  from  the 
copper-gold  veins  in  the  granitic  intrusives  near  Butte.  Lindgren 
regards  these  veins  as  connecting  links  in  age  between  the  distinctly 
Mesozoic  gold-quartz  veins  of  the  Sierra  Nevada,  Oregon,  and 
Idaho  and  the  propylitic  post-Miocene  veins  of  Colorado.  In  the 
Little  Rocky  and  Judith  mountains  towards  the  north-east  of  the 
State,  and  in  other  isolated  groups,  numerous  siliceous  replacements 
in  limestone  and  porphyry  are  gold-bearing.  These  replacement 
deposits  are  probably  to  be  associated  with  the  early  Tertiary 
phonolitic   eruptions. 

In  the  west  of  Montana,  on  the  Idaho  border,  the  Bitter-root 
mountains  are  composed  mainly  of  a  biotite-granite  (quartz- 
monzonite),  certainly  of  post-Carboniferous  and  probably  of  late 
Mesozoic  age.  In  these  intrusives  two  metalliferous  belts  are 
distinguished,  one  in  Montana,  and  the  other  further  to  the  west 
in  Idaho.  The  latter  have  furnished  rich  placer  deposits,  of  which 
the  more  important,  viz.,  those  near  Florence,  Dixie,  Elk  City,  &c, 
have  already  been  mentioned.  The  Montana  occurrences  have  not, 
on  the  other  hand,  proved  of  great  value.  Lindgren"  points  out 
an  important  feature  in  the  disposition  of  the  veins  of  the  Bitter- 
root  and  Clearwater  area.  The  central  granite  area,  whether  massive 
or  sheared,  lacks  veins  of  economic  value,  which  are  developed 
only  close  to  the  sedimentary  and  metamorphic  rocks  at  the 
periphery  of  the  granitic  mass. 

Marysville. — At  the  present  time  one  of  the  most  productive 
districts  is  that  of  Marysville,  Lewis  and  Clark  County.  The  rich 
placers  of  the  Silver  Bow  basin  furnished  the  clue  to  the  position 
of  the  parent  veins,  which  are  situated  on  the  edge  of  an  irregular 
batholith  of  quartz-diorite,  probably  related  in  origin  to  the  very 
much  larger  quartz-monzonite  batholith  of  the  Boulder  region. 
The  latter  contains  the  great  copper-silver  mines  of  Butte,  as  well 
as  those  of  Elkhorn  and  of  Unionville,  south  of  Helena.  The 
Marysville  district  is  18  miles  north-west  of  Helena.  It  is  formed 
by  a  central  batholith  of  quartz-diorite  intrusive  through  sedimentary 


a  Bull.  U.S.  Geol.  Surv.,  No.  213.  1903.  p.  70. 


572  NORTH    AMERICA. 

rocks  of  the  Belt  group  (Algonkian)."  The  sedimentary  rocks 
are  shales,  sandstones,  and  limestones,  little  altered  by  regional 
metamorphism,  despite  their  Algonkian  age.  The  igneous  rocks 
are  of  more  importance,  in  view  of  the  veins  developed  in  them. 
With  the  main  quartz-diorite  batholith  are  associated  micro- 
diorite  and  diorite-porphyry  dykes.  The  veins  occur  either  in  close 
proximity  to  the  igneous  contacts  or  adjacent  to  the  intrusive  dykes. 
The  absence  of  vein-fissures  in  the  centre  of  the  batholith  is  explained 
by  slower  cooling  in  that  portion,  while  general  shrinkage  produced 
the  radial  fissures  that  are  found  near  the  circumference.  The 
richest  mines  of  the  Marysville  district  have  been  the  Drumlummon 
and  the  Bald  Butte.  The  former  up  to  the  year  1903  had 
produced  ore  worth  nearly  £3,000,000.  Its  vein  is  parallel 
with  the  quartz-diorite  contact,  and  is  perhaps  typical  of 
those  of  the  district.  The  ores  occur  in  a  fault  plane  with 
quartz-filling.  The  quartz  is  white  and  opaque,  enclosing 
angular  fragments  of  black,  green,  and  drab  slate,  many  of 
-which  have  been  completely  replaced  by  ore.  While  the  vein 
has  been  opened  up  to  1,600  feet  vertically,  little  ore  has  been 
found  below  the  1,000-foot  level.  The  uppermost  200  feet  was 
especially  productive  of  bonanzas  or  rich  shoots,  but  below  that 
level  the  grade  of  ore  decreased  rapidly  with  increasing  depth. 
The  ore-shoots  were  well  defined  and  pitched  to  the  right-hand 
as  the  observer  looked  down  the  dip  of  the  vein.  The  shoots  were 
separated  by  intermediate  barren  stretches.  The  ores  are  sulphide 
and  sulph-antimonide  of  silver,  associated  with  gold,  the  latter 
forming  some  60  per  cent,  of  the  total  value. 

Veins  showing  similar  characters  occur  in  the  Granite-Bimetallic 
and  Cable  mines  of  the  Phillipsburgh  quadrangle,  Granite  County. 
The  values  are  mainly  in  enriched  silver  sulphides.  Surf  ace  waters 
have  leached  the  ore  from  an  upper  zone,  50  to  300  feet  in  thickness. 
Below  the  surface  zone  is  a  rich  oxidised  zone  with  large  quantities 
of  horn  and  native  silver.  Next  in  depth  is  a  belt  of  enriched 
sulphides,  while  below  the  enriched  sulphides  lies  the  low-grade 
primary  ore. 

Judith  Mountains. — The  placer  deposits  of  the  Judith 
mountains,  Fergus  County,  attracted  attention  about  1880.  Gold 
and  silver  veins  were  soon  afterwards  opened  out.  In  the  vicinity 
of  Maiden,  the  Spotted  Horse  and  Maginnis  mines  have  produced 
largely,  while  a  few  miles  further  south  are  the  Gilt  Edge  mines. 
The  Judith  mountain  ores  are  mainly  gold,  and  are  formed  of  country 

a  Barrell,  Prof.  Paper  U.S.  Geol.  Surv.,  No.  57,  1907  ;  Weed,  Bull.  U.S.  Geol.  Surv., 
No.  213,  1903,  p.  88. 


MONTANA. 


573 


impregnated  with  or  replaced  by  quartz  and  fluorite.  The  ores 
occur  :  (a)  in  fissures  in  the  great  rhyolite-porphyry  laccoliths  of 
the  region  ;  (6)  as  deposits  along  contacts  with  phonolite  dykes  ; 
and  (c)  in  the  Carboniferous  limestones  at  the  contact  of  an  irregularly 
intruded  mass  of  igneous  rock,  or  beneath  intruded  sheets  of 
rhyolite-porphyry. a      The  two  first-mentioned  occurrences  are  of 


Fig.  193.    Ore-deposit  at  contact  of  Pokphvry  (p)  and  Limestone  (I),  Maginnis  Mute, 

Montana  ( Weed). 

little  economic  importance,  while  the  last  has  yielded  all  the 
producing  mines  of  the  district.  As  shown  in  the  Spotted  Horse 
mine  the  contact  is  very  irregular  locally,  but  maintains,  nevertheless, 
a  general  dip  or  hade  when  viewed  broadly.  The  richest  ore  has 
been  found,  not  at  the  contact,  but  a  few  feet  away  from  it  and  well 
within  the  limestone.  Gold  is  most  abundant  in  the  masses  of 
quartz  and  fluorite.  Tellurides  of  gold  appear  to  have  furnished 
much  of  the  free  gold.  Fluorite  occurs  usually  in  a  finely  crystalline 
condition  intimately  mixed  with  quartz,  or  else  forming  small 
angular  blocks  in  the  limestone.  The  contact  zone  is  thoroughly 
impregnated  with  silica.  The  association  of  gold  and  fluorite  is, 
according  to  Weed,  fairly  intimate,  the  higher-grade  ores  of  the 
Spotted  Horse  mine,  for  example,  carrying  the  greater  quantity 


a  Weed  and  Pirsson,  18th  Ann.  Rep.  U.S.  Geol.  Surv.,  1898.  Pt.  IIT,  p.  588. 


574 


NORTH    AMERICA. 


of  fluorite.  There  is  thus  afforded  a  striking  contrast  to  the  occur- 
rence of  gold  and  fluorite  at  Cripple  Creek,  where  the  latter  mineral 
bears  no  relation  Avhatever  to  auriferous  deposition.  The  method  of 
ore-deposition,  as  at  Marysville,  is  by  siliceous  replacement  of  lime- 
stone. The  ore-bodies  are  exceedingly  irregular  in  form,  occurring 
in  pockets,  chimneys,  and  shoots.  The  richest  deposits,  as  a  rule, 
are  those  directly  underneath  an  inclined  contact  plane  of  rhyolite- 
porphyry  and  Carboniferous  limestone,  with  the  former  for  a 
hanging-wall.  Similar  contacts  of  porphyry  with  Cambrian  or 
Mesozoic  shales,  have,  however,  proved  unremunerative.  In  rare 
cases,  auriferous  deposits,  apparently  unconnected  with  porphyry, 
have  been  found. 

Little  Belt  Mountains. — The  Little  Belt  mountains  lie 
south-west  of  the  Judith  mountains  and  on  the  boundary  of  Fergus 
and  Meagher  counties.  The  principal  mining  camp  is  Neihart. 
The  ores  are  almost  entirely  lead-silver,  but  occasionally  carry 
small  quantities  of  gold.  The  veins  are  in  gneisses  and  schists  of 
supposed  Archaean  age/1 

Elkhorn. — The  silver-lead  veins  of  the  Elkhorn  district, 
Jefferson  County,  contain  also  small  quantities  of  gold.  Surface 
ores  yielding  as  much  as  1,447  ounces  of  silver  carried,  however,  only 
8  dwts.  gold.  The  present  ratio  of  silver  to  gold  is  fairly  constant 
in  the  lower  levels  and  may  be  taken  at  1,000  to  l.h  The  ore-deposits 
lie  in  a  massive  dolomitic  limestone  near  a  gabbro-diorite  intrusion, 
which,  while  it  has  exercised  no  apparent  influence  on  ore-deposition, 
is  nevertheless  believed  to  have  a  genetic  connection  with  the 
ore-body. 

The  total  production  of  gold  from  Montana  to  1900  inclusive 
is  estimated  at  £41,717,500    ($203,500,000).     Later  yields  are  :- 


Year.                          Value,  Dollars. 

Value,  Sterling. 

1901 
1902 
1903 
1904 
1905 
1906 
1907 

$4,744,100 
4,373,600 
4.411,900 

4,267,062 
4,889,300 
4,469,014 
4,206.345 

£972,540 
896,588 
904.439 
874,748 

1.002,306 
916,148 
S62.300 

Grand  Total  to| 
end  of  1907.. j 

$234,861,321 

£48,146,569 

"  Weed,  20th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  II,  1900,  p.  413. 
b  Idem.  22nd  Ann.  Rep.  U.S.  Geol.  Surv..  1901,  Pt.  Ill,  p.  475. 


575 

WYOMING. 

Compared  with  the  adjacent  States  to  the  west  and  to  the 
south,  and  especially  with  Colorado,  the  goldfields  of  Wyoming  are 
insignificant.  This  disparity  in  richness  is  largely  due  to  dissimilarity 
of  geological  structure.  The  greater  portion  of  the  mountain  mass 
of  Wyoming  is  composed  of  pre-Cambrian  granites  and  schists  that 
have  never  been  covered  or  even  intruded  by  those  Cretaceous  and 
Tertiary  igneous  rocks  to  which  Colorado,  Nevada,  and  Idaho  owe 
their  extensive  mineralisation.  The  Wyoming  auriferous  veins  are 
entirely  in  pre-Cambrian  rocks,  and  in  this  respect  are  comparable 
with  the  gold-quartz  veins  of  eastern  rather  than  of  western  North 
America. 

Simple  gold-quartz  veins  are  found  in  the  Atlantic  City  and 
South  Pass  districts  in  the  southern  part  of  Fremont  County. 
This  area  forms  the  southern  end  of  the  Wind  river  range,  which 
may  be  regarded  as  the  great  continental  divide  of  the  United 
States.  Its  western  drainage  is  taken  by  the  Snake  river  to  the 
Pacific,  its  southern  drainage  by  way  of  the  Green  river  to  the  Gulf 
of  California,  while  its  eastern  rainfall  finds  its  way  by  means  of 
the  Bighorn  and  North  Platte  rivers  eventually  to  the  Gulf  of 
Mexico.  The  Fremont  veins  are  in  pre-Cambrian  schists.  Owing 
to  their  great  isolation  (125  miles  from  a  railroad),  little  work  has  been 
done  on  them  and  little  is  known  of  the  geology  of  the  district." 

Copper-gold  veins  occur  in  Carbon  and  Albany  counties  near 
the  Colorado  border.  The  principal  district  is  the  Encampment, 
described  by  Spencer. b  The  chief  mines  (Rambler  and  Haggarty) 
are  working  on  impregnated  brecciated  zones  in  pre-Cambrian 
quartzite.  The  sulphides  present  are  chalcopyrite,  pyrite,  and 
chalcocite,  the  last  arising  from  secondary  enrichment.  The 
proportion  of  gold  is  small. 

Placer  gold  in  small  quantities  has  been  found  derivative  from 
veins  of  both  the  foregoing  classes.  It  'also  occurs  in  the  Snake 
river,  which  runs  through  the  western  part  of  Idaho.  On  the  Snake 
river  the  Davis  diggings  at  the  mouth  of  the  Grand  Canyon  of  the 
Snake  are  the  most  noteworthy.  The  Snake  river  gold,  as  in  Idaho 
and  in  Oregon,  is  exceedingly  fine.  No  less  than  4,000  to  4,800 
"  colours  "  are  required  to  make  up  one  grain  weight  of  gold  (1,000 
to  1,200  to  one  cent).c  The  method  of  recover  of  the  gold  of  the 
Snake  river  has  already  been  indicated.  In  the  north-east  of 
Wyoming,  near  the  South  Dakota  border,  placer  gold,  believed  to 


a  Lindgren,  Min.  Res.  U.S.,  1905,  p.  338  ;  Id.,  Trans.  A.I.M.E.,  XXIII.  1903,  p.  839. 
b  Prof.  Papers,  U.S.  Geol.  Surv.,  XXV,  190-1,  p.  50. 
c  Schultz,  Bull.  U.S.  Geol.  Surv.,  No.  315,  1907,  p.  77. 


576 


NORTH    AMERICA. 


be  derived  from  Cambrian  conglomerates  resembling  those  of  the 
Black  Hills,  has  been  washed. 

The  yield  of  gold  from  Wyoming  to  1900  has  been  estimated 
at  £205,000  ($1,000,000).     Since  then  there  has  been  obtained  :  — 


Year. 

Value,  Dollars. 

$12,700 

Value,  Sterling. 

1901 

£•2,603 

1902 

38.800 

7,954 

1903 

3,600 

738 

1904 

17.305 

3,548 

1905 

23,700 

4,858 

1906 

6,521 

1,337 

1907 

4.860* 

1,000* 

C4rand  Total  to  1907. 

$1,107,486 

£227.038 

*  Estimated. 


SOUTH    DAKOTA. 

Gold  mines  in  South  Dakota  are  restricted  not  merely  to  the 
Black  Hills,  which  cross  the  south-west  frontier  of  the  State  into 
Wyoming,  but  also  to  an  area,  within  the  Black  Hills,  of  less  than  100 
square  miles,  lying  in  the  immediate  vicinity  of  Deadwood  City.  The 
attention  of  miners  was  directed  to  these  deposits  in  the  usual  way, 
viz.,  by  the  discovery  of  placer-gold.  The  gravels  of  Whitewood  and 
Deadwood  gulches  were  first  washed  for  gold  towards  the  end  of  1875. 
In  the  following  year  the  now  famous  Homestake  lodes  were  traced 
on  the  surface,  and  by  the  end  of  1877  the  principal  Homestake  com- 
panies— the  Homestake,  Father  de  Smet,  Highland,  and  Deadwood 
Terra — had  been  established.  These  have,  until  quite  recently,  been 
uniformly  successful.  Afire  occurred  in  the  mine  in  March,  1907, 
and  necessitated  its  flooding,  with  a  consequent  cessation  of  activity 
for  some  three  months.  The  mine  operations  were  also  adversely 
affected  in  1907  by  labour  troubles.  As  early  as  1880  no  less  than 
740  stamps  had  been  installed  to  crush  the  ores  of  the  Homestake 
belt.  In  1900  the  annual  amount  of  ore  crushed  was  some  900,000 
tons.  The  average  mining  and  milling  costs  were  then  a  little  more 
than  8s.  4d.  ($2.00)  per  ton,  of  which  milling  charges  amounted 
to  3s.  4d.  ($0.80)  per  ton.  The  Homestake  Company  alone,  for  a 
complete  period  of  10  years,  from  June  1st,  1881,  to  June  1st,  1900, 
had  crushed  5,685,771  tons  ore  for  a  yield  of  £6,288,197  ($30,674,132), 
and  had  paid  in  dividends  £1,777,094  ($8,668,750).  Prior  to  1881, 
about  £120,000  ($600,000)  had  already  been  distributed  among 
shareholders.     The  total  product  of  the  Homestake  belt  to  June, 


SOUTH    DAKOTA. 


577 


1900,  appears  to  have  been  about  £12,270,648  ($59,856,822),  and 
the  total  dividends  from  this  yield    £2,351,913  ($11,472,750)/' 


Igneous 
Tertiary 

I 


r 

,,    M   „■    ' 

*mm 

© 

[      ^  1  Jura-Trias 


Carboniferous 
Cambrian 

Arrlaran 
Granite 


Scalp  of  Miles 


Fig.  194.     Geological  Map  of  the  Southern  Black  Hills,  South  Dakota  (Newton).. 

The  Black  Hills  rise  like  a  long  island  above  the  level  of  the 
plains.  They  form  a  typical  geological  dome  with  a  central  core  of 
metamorphic  crystalline  rocks.     About  the  core  are  grouped  later 

a  Emmons  (S.  F.)  and  Jaggar,  Prof.  Papers  U.S.  Geol.  Surv.,  No.  26,  1904. 

Nl 


578  NORTH    AMERICA. 

sedimentary  strata,  disposed  in  plan  in  rudely  concentric  rings, 
all  the  beds  dipping  away  from  the  central  dome  of  elevation.  In 
the  northern  hills  four  groups  of  rocks  may  readily  be  distinguished. 
The  lowest  is  the  central  core  of  Algonkian  metamorphic  schists, 
for  the  most  part  of  sedimentary  origin.  They  are  crystalline  mica- 
schists,  quartz-schists,  mica-slates,  or  phyllites,  with  which  are 
associated  graphitic,  garnetiferous,  and  chloritic  slates  and  quartzites . 
Metamorphosed  igneous  rocks  are  represented  by  amphibolites 
that  probably  occurred  originally  as  irregular  dykes  in  the  Algonkian 
rocks.  In  the  southern  portion  of  the  Black  Hills,  the  place  of  the 
amphibolite  is  largely  taken  by  a  granite,  which  is  occasionally 
tin-bearing. 

Above  the  Algonkian  rocks  are  those  of  the  Deadwood  (Middle 
Cambrian)  system.  Their  basal  member  is  almost  invariably  a  con- 
glomerate. Succeeding  members  are  alternating  quartzites, 
limestones,  and  shales,  the  whole  having  a  total  thickness  of  some 
400  feet.  Overlying  the  Cambrian  rocks  is  a  buff-coloured  Ordovician 
limestone,  which,  in  its  turn,  is  succeeded  by  the  Carboniferous 
limestones  of  the  Pahasapa  and  Englewood  series.  Later  Mesozoic 
and  Cainozoic  rocks  occur  in  the  region,  but  need  not  now  be 
considered,  auriferous  deposits  occurring  only  in  the  Algonkian, 
Cambrian,  and  Carboniferous  rocks. 

Numerous  porphyry  dykes,  differing  widely  in  type,  are  intrusive 
through  the  sedimentary  rocks.  These  volcanic  rocks  have  been 
divided  by  Irving  a  into  grorudite  (a  highly  alkaline  rock  containing 
orthoclase,  quartz,  aegerine-augite,  and  aegerine),  phonolite, 
rhvolite-porphyry  and  dacite,  andesite-porphyry,  diorite-porphyry, 
and  diorite,  together  with  more  basic  (lamprophyre)  dyke  rocks. 
The  evidence  available  points  to  an  Eocene  age  for  the  majority 
of  these  eruptives. 

The  Homestake  belt  of  mines  in  the  Algonkian  schists  extends 
from  the  town  of  Lead  and  from  Gold  Run  Gulch  north-westward 
to  Deadwood  and  Sawpit  Gulches.  The  three  principal  mines 
on  this  belt  are  the  Homestake,  Clover  Leaf,  and  Columbus.  The 
ores  of  the  Homestake  belt  in  the  metamorphic  schists  are  ill- 
defined  masses  of  rock  sufficiently  impregnated  with  gold  to  pay 
the  expenses  of  working.  The  gold  is  exceedingly  fine  and  can 
rarely  be  detected,  even  with  a  hand-lens.  Arsenopj^rite  and  pyrite 
are  generally  present,  but  carry  no  more  gold  than  quartz,  the 
ordinary  and  most  abundant  matrix,  which  occurs  mainly 
in  lenticular  masses.  Calcite  and  dolomite  are  also  abundant. 
Silicification  and  ore-deposition  appear  to  have  taken  place  along 
two  converging  zones  of  crushing,  one  striking  N.  10°  W.  and  the 

a  Ann.  New  York  Acad.  Sci.,  XII,  No.  9,  p.  244. 


SOUTH    DAKOTA. 


579 


other  N.  30°  W.  Along  the  same  channels  a  comparatively  recent 
mineralization,  yielding  pyrite  and  gold,  has  taken  place  at  the 
period  of  or  subsequent  to  the  intrusion  of  the  presumably  Tertiary 
rhyolite-porphyry.  Secondary  surface  enrichment  in  the  Homestake 
belt  has  been  a  factor  of  little  importance,  since  the  outcrop  ores 


Fig.  195.     Geological  Map  of  Neighbourhood  of  Lead  City,  South  Dakota  (Irving). 
S.  Algonkian  schists.     Cb.  Basal  Cambrian  conglomerate.     C.  Cambrian.     R.  Eruptive  rocks 
(chiefly  rhyolite).    D.  Dykes.    A.  Areas  underlain  by  gold-producing  basal  Cambrian  conglomerate. 

are  said  to  have  assayed  no  more  than  £3.  3s.  8d.  ($16.00)  per  ton. 
In  depth  the  general  tenor  of  the  ore  is  perhaps  23s.  ($5.50)  per  ton. 
In  the  Clover  Leaf  mine  the  gold  is  always  associated  with  galena, 
and  sometimes  occurs  there  as  small  nugget-like  masses,  J-inch 
in  diameter,  and  completely  enclosed  within  galena.  The  smaller 
masses  of  gold  frequently  show  crystal  faces. 


r.so 


NORTH    AMERICA. 


The  auriferous  deposits  of  the  Cambrian  rocks  of  the  Black  Hills 
have  of  late  years  grown  considerably  in  importance.  They  are 
subdivided  by  Emmons"   into  :  — 

(a)  Gold-bearing  conglomerates. 
(6)  Refractory  siliceous  ores, 
(c)  Pyritous  ores. 

The  auriferous  conglomerate  lies  at  the  base  of  the  Cambrian 
and  on  the  upturned  edges  of  the  Archaean  schists.     It  varies  in 


scale 


100'ltv 


■MR  wKMKm 


Fig.  196.     Star-Old  Abe  section,  Homestake  Mine  (Emmons). 

thickness  from  a  few  inches  to  30  feet,  with  an  average  of  perhaps 
3  to  4  feet.  It  passes  upward  into  a  hard  dense  quartzite  of  the  same 
character  as  that  which  forms  the  interstitial  matter  between  the 
pebbles  of  the  conglomerates.  The  conglomerate  pebbles  are  well- 
rounded  and  water-worn  fragments  of  Algonkian  quartz  or  quartzite 
with  a  few  schist  pebbles  intermingled.  Their  average  size  is  from 
1£  to  3  inches  in  diameter,  though  boulders  a  foot  thick   may  be 


fflLoc.  cit.,  p.  '.is. 


SOUTH    DAKOTA. 


581 


encountered.  The  auriferous  portions  of  the  conglomerate  are 
easily  recognised  by  the  invariable  association  of  pyrite  with  the 
gold,  or  by  the  ferruginous  cement  derived  from  the  oxidation  of 
the  pyrite.  Barren  conglomerate  is  cemented  by  quartzite  or  by 
calcite  free  from  pyrite.  Emmons  concludes,  from  its  water-worn 
character  and  from  its  concentration  near  bed-rock,  that  some  of 
the  gold  is  detrital  in  origin,  and  that  this  portion  was  derived  from 
the  erosion  of  the  outcrops  of  the  ore-bodies  of  the  neighbouring 
Homestake  belt,  along  the  strike  of  which  outliers  of  the  rich 
conglomerate  lie ;  and  further,  that  while  some  of  the  gold  is  detrital, 
the  increase  from  a  low  tenor  of,  say,  4s.  ( $1.00)  per  ton  to  the  higher 


ian  schist 


Fig.  197.     Section  through  Hawkeye-Plitma  Mine,  showing  Gold-bearing  Conglomerate 

{Emmons). 

average  of  40s.  ($10.00)  per  ton,  is  nevertheless  due  to  local  secondary 
enrichment.  The  enriching  gold  is  considered  to  have  been  intro- 
duced with  the  pyrite,  which  is  certainly  subsequent  in  age  to  the 
deposition  of  the  conglomerate  along  the  ancient  shores  of  the 
Homestake  area.  That  this  is  the  case  is  shown  by  the  pyrite 
occupying  fissures  and  cavities  in  the  pebbles.  The  argument  for 
secondary  enrichment  is  strengthened  by  the  occurrence  of 
films  of  gold  in  the  laminations  of  the  schist  and  from 
3  to  10  feet  below  the  base  of  the  conglomerate.  At  the 
Hawkeye-Pluma  ore  enrichment  appears  to  have  taken  place 
from  above  through  fissures  in  the  sandy  roof.  According  to 
Devereux,  however,  the  gold  of  the  Cambrian  conglomerates  is  to 
be  considered  entirely  detrital." 

The  richest  conglomerate  area  worked  lay  between  Bobtail 
and  Deadwood  Gulches,  and  was  worth    in    places   £10    ($50.00) 


a  Trans.  Amer.  Inst.  M.E.,  X,  1889,  p.  465. 


582 


NORTH    AMERICA. 


per  ton.     Small  water-worn  nuggets  weighing  nearly  3  dwts.  have 
been  obtained  in  the  matrix." 

A  third  and  increasingly  important  source  of  gold  in  the  Black 
Hills  is  the  refractory  siliceous  ore  of  the  Cambrian  rocks.  These 
ores  are  widely  distributed  over  a  broad  irregular  belt  extending 
from  Yellow  Creek  on  the  south-east  to  Squaw  Creek  on  the  north- 
west.   The  ore  is  a  hard,  brittle  rock,  made  up  mainly  of  secondary 


||fP«» 


l^Sch.st 


Cement  mines 


Porphyry 


Pot  s  d  a  ni 


Fig.  198.     Geological  section-  from  Homestaee  Mine  eastward  (Devereux). 

silica,  and  carrying,  when  fresh,  pyrite,  fluorite,  and  other  accessory 
minerals.  It  occurs  as  flat,  more  or  less  banded  masses  which 
have  a  channel-like  form,  and  are  parallel  or  nearly  parallel  to  the 
bedding  planes  of  the  gently-inclined  fine-grained  dolomitic  lime- 
stones in  which  they  are  found.    The  "  shoots,"  as  they  are  termed, 


2«( 


Figs.   199  and  200.     Sections  showing  Siliceous  Ore-shoots  in  Dolomite,  Black  Hills 

(Irving). 
1.  Algonkian  schists.    2.  Conglomerate.    3.  Hard  quartzite.    4.  Dolomite.    5.  Slate  (impervious). 

6.  Porphyry.     7.  Ore-shoot. 

follow  in  horizontal  extension  almost  vertical  fissures  ("  verticals"). 
In  wide  ore-bodies  the  bottom  of  the  ore-body  may  drop  along 
fractures  far  below  the  base  of  the  dolomitic  belt  in  which  the  mass 
of  the  ore  lies.  In  a  few  cases  it  is  possible  to  trace  the 
"verticals  '      into     the    Algonkian     schists     below.       There     are 


a  Loc.  cit.,  p.  469. 


SOUTH    DAKOTA. 


583 


apparently  two  auriferous  horizons  :  (a)  the  '  lower  contact," 
15  to  25  feet  above  the  Algonkian  schists  and  therefore 
immediately  over  the  basal  quartzite  or  conglomerate  ;  and  (b) 
the  "  upper  contact,"  18  to  30  feet  below  the  Scolithus,  or 
"  worm-eaten,"  sandstone,  the  uppermost  bed  of  the  Cambrian. 
The  width  of  the  "  shoots  "  varies  from  a  few  inches  to  300  feet, 
while  they  have  an  average  thickness  of  perhaps  six  feet.  Their 
extension  along  the  vertical  fissure  may  reach  three-fourths  of  a 
mile.  The  ore  is  high  in  grade.  In  the  main  or  Bald  Mountain  area 
it  is  £3.  lis.  ($17.00)  per  ton,  while  in  the  Lead  and  Yellow  Creek 
districts  it  may  reach  £9.  4s.  6d.  ($45.00)  per  ton.  A  genetic 
relation  between  the  eruptive  porphyries  and  ore-deposition  has 
been  traced  by  Smithy  but  the  relation  is  denied  by  Irving.6 

Low-grade  pyritous  ores  in  limestones  have  also  been  mined 
in  the  Black  Hills,  but  have  not  so  far  proved  of  great  value.  They 
show  a  great  analogy  with  the  refractory  siliceous  ore,  from  which 
they  differ  only  in  that  the  dolomitic  country  has  been  replaced 
by  pyrite  instead  of  silica. 

The  Carboniferous  limestones  of  the  Black  Hills,  like  the 
underlying  Cambrian  limestones,  carry  gold  and  silver  ores  of  the 
refractory  siliceous  type.  These  occur  chiefly  in  the  vicinity  of 
Ragged  Top  Mountain;  they  were  not  discovered  until  1896. 
The  ore  is  largely  a  siliceous  replacement  of  a  brecciated  limestone. 
Tellurides  are  present,  as  shown  by  analysis,  but  have  not  certainly 
been  detected  in  hand  specimens.0 

The  total  gold  production  of  South  Dakota  is  shown  in  the 
following  table  : — 


Year. 

Value,  Dollars. 

Value,  Sterling. 

1900 

$90,000,000 

£18,450,000 

1901 

6,479,500 

1,328,297 

1902 

6,965,400 

1,427,907 

1903 

6,826,700 

1,399,473 

1904 

7,363,977 

1,509,615 

1905 

6,913,900 

1,417,350 

1906 

6,841,469 

1,392,501 

1907 

4,085,446* 

837,516 

Grand  Total  to  end 
of  1907. 

$135,476,392 

£27,762,659 

♦Estimated;  Prelim.  Rep.  Dir.  U.S.  Mint,  Jan.,  1908. 


"  Smith,  F.  C,  Trans.  Amer.  Inst.  M.E.,  XXVII,  1897,  p.  420. 
6  Loc.  cit.,  p.  116. 
c  Loc.  cit.,  p.  418. 


584  NORTH    AMERICA. 

MINNESOTA. 

The  auriferous  region  of  the  Rainy  Lake  in  Canada  extends 
southward  across  the  international  boundary  into  Minnesota. 
The  geology  of  the  Minnesota  occurrences  is  similar  to  that  of  the 
Ontario  region  already  described.  The  oldest  rocks  are  Laurentian 
granitoid  gneisses  and  granites.  These  are  succeeded  by  Huronian 
rocks,  separable  into  upper  (Keewatin)  and  lower  (Coutchiching) 
members.  All  are  intruded  by  diabase  dykes  of  possible 
Keeweenawan  age.  The  auriferous  quartz  veins,  as  in  Ontario, 
lie  for  the  most  part  within  Keewatin  "greenstones"  or  "green 
schists,"  which  represent  ancient  lavas  and  ash-beds.  Associated 
with  the  "  greenstones  "  of  the  Keewatin  series  are  conglomerates, 
slates,  sericite-schists,  agglomerates,  and  grauwackes. 

Auriferous  veins  were  not  worked  in  the  State  until  1893,  when 
the  Little  American  mine,  on  an  island  in  Rainy  Lake,  was  discovered. 
A  small  mill  was  erected  and  crushed  about  500  tons  for  a  yield  of 
£950  ($4,635).  The  available  ore  was  then  exhausted  and  the  mine 
was  closed  down.  In  addition  to  gold-quartz  veins,  impregnated 
bands  of  country,  carrying  gold,  have  been  met  with,  as  at  the 
Lyle  mine,  near  Rainy  Lake  City." 


MAINE. 

Various  cupriferous  lodes  have  from  time  to  time  been  reported 
to  contain  gold  in  small  quantities.  At  Baileyville,  in  the  south- 
east of  the  State  and  near  the  New  Brunswick  border,  gold-quartz 
veins  occur  in  pyritous  mica-schist.  These  are  apparently  of  no 
present  economic  value.6 


NEW  HAMPSHIRE. 

Schistose  rocks,  similar  to  those  forming  the  bed-rock  of  the 
Chaudiere  goldfields  in  Quebec,  occur  along  the  Connecticut  river 
in  the  north  of  New  Hampshire.  These  schists,  as  well  as 
the  talcose  schists  of  the  Green  mountains  in  Vermont,  are 
probably  of  Huronian  age.c  They  contain  small  auriferous  veins. 
The  Dodge  vein,  at  Lyman,  near  the  Lower  Ammonoosuc  river, 
is  the  most  important.  It  is  16  feet  wide,  with  well-defined  ore- 
shoots.  Its  gangue  is  quartz,  slate  fragments,  and  ankerite.  Free 
gold  occurs  with  galena  and  barren  pyrite.     The  gold  is  917   fine. 

"  Winchell  and  Grant,  Geol.  Surv.  Minnesota,  IV,  1896-1898,  p.  192. 

6  Holmes  and  Hitchcock,  2nd  Ann.  Rep.  Geol.  Surv..  Maine,  1862.  p.  423. 

c  Becker,  16th  Ann.  Rep.  U.S.  Geol.  Surv.,  Part  III,  1895,  p.  331. 


NEW    HAMPSHIRE.  585 

The  value  of  the  ore  varies  between  12s.  6d.  and  79s.  ($3.00  and 
$19.00)  per  ton.  The  vein  is  said  to  have  produced  £10,000  ($50,000) 
to  the  end  of  1877.° 

VERMONT. 

Gold  has  been  found  along  a  belt  some  20  miles  in  width  lying 
to  the  eastward  of  the  Green  mountains.  The  rocks  of  the  belt 
are  talcose  (sericitic  ?)  schists  and  slates  with  mica-gneiss.  The 
Long  Ditton  auriferous  belt  near  the  head  of  the  St.  Francis  river 
in  Quebec  is  apparently  the  north-easterly  continuation  of  the 
belt.  The  age  of  the  Vermont  rocks,  is  therefore,  probably  pre- 
Cambrian.  With  the  schistose  rocks  are  found  steatite  and 
serpentine,  representing  basic  igneous  rocks  intrusive  through  the 
schists.  The  gold  deposits  are  possibly  in  intimate  genetic  connection 
with  these  basic  rocks. h  The  more  important  auriferous  occurrences 
are  those  which  were  found  in  1853  in  the  vicinity  of  Plymouth 
and  Bridgewater,  Windsor  County.  Small  pockets  of  gold  have 
occasionally  been  met  with  in  the  quartz  veins  of  the  district,  but 
the  yield  has  always  been  too  small  to  warrant  the  establishment 
of  a  gold-mining  industry.  A  small  placer  deposit  near  Plymouth 
is  said  to  have  produced  between  1855  and  1861  from  £1,800  to 
£2,600  ($9,000  to  $13,000)  gold.c  Even  this  amount  failed,  in  all 
probability,  to  cover  the  high  working  expenses  due  to  extravagance 
and  inexperience.  

NEW  YORK. 

Gold  has  been  recorded  from  quartz  veins  in  mica-schist  at 
Rhinebeck  and  Wassaic,  near  the  Hudson  river,  Dutchess  County ; 
also  from  quartz  from  the  north  end  of  Manhattan  Island.  Assays 
of  the  latter  quartz  gave  returns  of  16s.  8d.  ($4.00)  per  ton.d 


MARYLAND. . 

The  auriferous  occurrences  of  Maryland  lie  immediately  to  the 
north-east  of  the  Potomac  river  in  the  picturesque  region  of  the 
Great  Falls,  16  miles  from  Washington.  They  are  small  pockets 
of  free  gold  in  veinlets  in  Algonkian  mica-schist.  The  total  breadth 
of  the  schist  belt  is  here  about  50  miles,  but  the  gold-quartz  veins 
are  restricted  to  a  band  7  to  8  miles  wide.  They  lie  along  a  well- 
marked  zone  of  Assuring  and  are  directly  on  the  strike  of  a  diabase 
dyke  traceable  far  to  the  south  in  Virginia. 

a  Hitchcock,  "  Geology  of  New  Hampshire,"  Pt.  V,  1878,  p.  7. 
b  Smith,  G.  O.,  Bull.  U.S.  Geol.  Surv..  No.  255,  1904,  p.  88. 
c  Hager,  Vermont  Geol.  Surv.,  II,  1861,  p.  844. 
*  Becker,  loc.  cit.  sup. 


586 


NORTH    AMERICA. 


The  gold  is  found  in  pure,  often  drusy,  white  quartz,  free  from 
pyrite  ;  associated  with  pyrite  ;  and  in  the  pyrite  itself.  It  is 
also  found  impregnating  the  schists  adjacent  to  the  veins.  Alluvial 
gold  derived  from  the  local  veins  has  formed  the  greater  part  of  a 
total  Maryland  yield  estimated  at  about  £9,200  ($46,068).  From 
the  Montgomery  mine,  gold  valued  at  £1,600  ($8,000)  was  obtained 
prior  to  1890.  Most  of  the  gold  recovered  was  coarse,  containing 
nuggets  weighing  3  and  4  ounces. a 

In  December,  1904,  the  Maryland  mine,  which  was  working 
from  a  shaft  180  feet  deep,  crushed  504  tons  for  a  yield  of  £1,054 
($5,144).&  The  total  quantity  of  gold  ore  treated  in  Maryland  in 
1905  was  only  2,698  tons,  containing  an  average  value  of  23s.  ($5.51) 
per  ton.  

VIRGINIA. 

The  Great  Falls  schist  belt  is  continued  south-west  across 
the  Rappahannock  through  Spotsylvania,  Orange,  Louisa,  and 
Fluvanna  counties  to  the  James  river,  and  across  that  river  into 
Buckingham  County.  The  characters  of  country  and  veins  are 
those  of  the  Potomac  area.  The  total  yield  of  Virginia  to  1900 
is  estimated  at  £656,706  ($3,203,443).  The  greater  part  of  this 
appears  to  have  been  obtained  before  the  Civil  War.  According 
to  Whitney  c  the  Marshall  mine  on  the  Rappahannock  river  had 
before  1854  produced  about  £60,000  ($300,000)  gold.  At  the  present 
time  one  of  the  few  profitable  gold  mines  of  the  Appalachian  States 
appears  to  be  the  Goldbank,  six  miles  north  of  Virgilina.^ 


SOUTHERN    APPALACHIAN  STATES. 

For  the  better  consideration  of  the  auriferous  occurrences  of 
the  Southern  Appalachian  belts,  five  political  divisions —North 
Carolina,  South  Carolina,  Georgia,  Tennessee,  and  Alabama — 
may  be  conveniently  grouped  and  regarded  as  a  single  area.  The 
already-mentioned  scattered  gold  mines  of  Virginia  and  Maryland 
are  to  be  considered  as  merely  the  northern  prolongation  of  the 
most  easterly  southern  auriferous  zone  of  the  Southern  Appalachian 
region. 

Nebulous  rumours  of  gold  in  the  interior  reached  the  ears  of 
the  earliest  of  the  Spanish  adventurers  on  the  North    American 

a  Emmons,  S.  F.,  Trans.  Amer.  Inst.  M.E.,  XVIII,  1890,  p.  391. 

'•  Weed,  Bull.  U.S.  Geol.  Surv.,  No.  260,  p.  129. 

c  "Metallic  Wealth  of  the  United  States,"  1854,  p.  125. 

d  Judd,  Eng.    Min.    Jour..    Feb.    16,   1907 ;    Nitze   and    Wilkens,  Bull.  N.C.   Geol. 
Surv.,  X,  1897,  p.  71. 


APPALACHIAN    STATES. 


58^ 


main.  In  1513,  Ponce  de  Leon,  seeking  in  Florida  the  elusive 
fountain  of  eternal  youth,  heard  them,  but  it  was  only  some 
14  years  later  that  they  took  definite  shape.  Narvaez  then  learned 
from  the  Indians  that  the  gold  in  their  possession  came  from  a 
region  called  Appalache,  far  in  the  interior.  Fugitive  references 
to  gold  are  made  by  subsequent  explorers,  but  it  was  near  the 
end  of  the  eighteenth  century  before  statements  of  actual  occur- 
rences in  clearly  specified  localities  were  made.  In  1782  a  fragment 
of  quartz  four  pounds  in  weight  and  containing  17  dwts.  gold  was 
found  in  the  Rappahannock  river  in  Virginia.  In  the  first  years 
of  the  nineteenth  century  large  nuggets  of  gold,  one  of  which  weighed 
28  pounds,  were  obtained  near  the  present  Reed  mine,  Cabarrus 
County,  North  Carolina.  Gold-washing  appears  to  have  first  been 
practised  in  this  State  about  1804.  By  1827  there  had  been  recovered 
some  £22,500  ($110,000)  alluvial  gold.  Two  years  earlier  the  first 
gold-quartz  veins  of  the  State  were  worked  in  Montgomery  County. 
Both  in  South  Carolina  and  in  Georgia  the  first  extensive  gold 
discoveries  were  made  about  1829.  In  the  former  State  the  famous 
Brewer  mine  was  being  worked  in  1830  or  1831.  The  Georgian 
discoveries  caused  general  excitement,  and  in  1830  a  miniature 
rush  to  the  placer  deposits  of  Habersham  County  took  place. 
At  one  time  no  less  than  6,000  to  7,000  men  were  busily  engaged 
in  washing  gravels.  The  excitement  engendered  by  the  Georgian 
discoveries  led  to  vigorous  prospecting  in  the  neighbouring  States. 
As  a  direct  result,  many  auriferous  veins  were  located  in  Virginia  ; 
and  the  Cherokee  Indian  reserves  in  Georgia  and  Alabama,  known 
to  be  gold-bearing,  but  up  to  then  closed  for  mining,  were  thrown 
open  to  prospectors.  Prior  to  the  opening,  in  1849,  of  the  great 
goldfields  of  California  and  the  west,  the  mines  of  Virginia,  the 
Carolinas,  Georgia,  and  Alabama,  were  vigorously  worked,  and  indeed 
supplied  most  of  the  gold  coinage  of  the  United  States.  In  the 
'fifties  they  declined  considerably,  while  the  long  cessation  of 
industrial  operations  during  the  Civil  .War  dealt  a  blow  from 
which  they  have  not  even  yet  recovered.  The  following  table 
shows  the  gold  production  of  the  various  Appalachian  States  from 
1901    to  1906  inclusive  :  — 


State. 

Value,  Dollars. 

Value,  Sterling. 

.Maryland 

§20,200 

£4.141 

Virginia 

45,532 

9,334 

North  Carolina 

546,631 

112,059 

South  Carolina 

565,159 

115,858 

Georgia 

509.150 

104.376 

Alabama 

105.721 

21.672 

Tennessee 

13.238 

2.714 

588 


NORTH    AMERICA. 


Details  of  the  total  yields  of  the  separate  States  are  not  accessible. 
Combined  yields  of  the  various  Appalachian  States  are  :  — 


Year. 

Value,  Dollars. 

Value,  Sterling. 

1799  to    1900 

$47,000,000 

£9,635,000 

1901 

235,100 

48,195 

1902 

318,500 

65,293 

1903 

252,400 

51,742 

1904 

382,400 

78,3&2 

1905 

380,500 

78,003 

1906 

236,731 

48,530 

1907 

215,275 

44,131 

Grand    total    to  | 
end  of  1907 . .  j 

$49,020,906 

£10,049,286 

Following  Becker,"  the  Southern  Appalachian  gold  regions  may 
be  conveniently  divided  into  three  main  belts  :  (a)  the  Georgia  belt 
extending  from  near  Montgomery,  Ala.,  in  a  north-easterly  direction 
by  way  of  Dahlonega  through  North  Georgia,  and  so  into  North 
Carolina  ;  (6)  the  South  Mountain  belt  in  North  Carolina  ;  and  (c) 
the  Carolina  belt,  the  most  easterly  and,  like  the  first,  parallel  in 
strike  to  the  Appalachian  trend.  It  stretches  from  South  Carolina 
north-east  by  Charlotte  into  North  Carolina.  The  Virginian  and 
Maryland  occurrences  already  described  are  on  the  strike  of  the 
last-named  belt. 

The  Georgia  belt  runs  north-east  from  near  Montgomery  in 
eastern  Alabama  through  northern  Georgia  as  far  as  the  North 
Carolina  boundary.  The  direction  of  the  belt  and  of  the  schistosity 
of  its  rocks  is  therefore  parallel  with  that  of  the  axes  of  Appa- 
lachian folding.  The  rocks  of  this  belt  are  Archaean  micaceous 
and  hornblendic  gneisses  and  schists,  representing  possibly  sheared 
granitic  and  dioritic  rocks.  Diabase  dykes  are  almost  unknown, 
their  place  being  apparently  taken  by  granitic  intrusions  of  probable 
Algonkian  age.  The  Archaean  schists  are  bounded  to  the  north- 
west by  the  Ocoee  formation  (Palaeozoic  or  Algonkian).  The 
majority  of  the  veins  of  the  belt,  as  indeed  of  the  Appalachian  region 
generally,  conform  closely  to  the  strike  and  dip  of  the  enclosing 
rocks.  Occasionally,  however,  while  remaining  parallel  in  strike 
they  may  cut  across  the  dip  at  low  angles.  The  ore-deposits  are 
generally  contained  as  numerous  narrow  and  discontinuous  lenses 
in  zones  of  fracture  and  Assuring.  The  better-known  mines  on  the 
belt  are  all  in  northern  Georgia,  and  more  particularly  in  the  vicinity 
of  Canton,  Auraria,  and  Dahlonega.     The  Franklin  veins,  14  miles 

"  16th  Ann.  Rep.  U.S.  Geol.  Surv.,  Pt.  III.  1895,  p.  252. 


APPALACHIAN    STATES.  589 

north-west  of  Canton,  lie  in  gneissoid  mica-schists.  The  wall  rocks 
are  undulating,  and  corrugated  quartz  veins  that  recall  the  "  barrel- 
quartz"  of  Nova  Scotia,  have  been  produced.  The  ore  is  low-grade, 
being  worth  about  25s.  ($6.00)  per  ton.  Half  the  gold  is  free  milling, 
clean  concentrated  sulphides  carrying  somewhat  less  than  £12 
($56.00)  in  gold.  Numerous  gold  mines  are  found  near  Dahlonega 
and  Auraria,  where  the  deposits  lie  nearly  all  on  contacts  either  of 
the  prevailing  mica-schist  and  amphibolite  or  of  mica-schist  and 
granite.  At  no  place  are  the  veins  far  from  granitic  intrusions. 
The  dominant  quartz-mica-schist  is  regarded  by  Lindgren0  as  an 
altered  sedimentary  rock,  while  the  amphibolite  is  a  highly  metamor- 
phosed original  diabase  or  diorite.  The  country  generally  has  been 
greatly  eroded,  perhaps  to  the  extent  of  15,000  to  20,000  feet, 
since  the  period  (Algonkian)  of  vein-deposition.  The  outcrops  now 
showing  represent,  therefore,  the  roots  of  the  original  fissures. 
Lindgren  compares  the  Dahlonega  occurrences  with  those  of 
California  and  of  Victoria,  Australia,  especially  in  their  association 
with  and  possible  dependence  on  granitic  intrusions,  but  the  evidence 
here  is  by  no  means  so  clear  as  in  the  two  richer  regions.  Indeed, 
some  granitic  intrusions  are  certainly  later  than  the  period  of  vein- 
deposition,  as  is  shown  in  the  case  of  the  faulting  of  quartz  veins, 
by  a  pegmatite  dyke  at  the  Thompson  mine  near  Nacoochee,  Ga. 
In  the  present  case,  however,  it  is  considered  more  probable,  when 
the  general  relations  of  the  whole  series  are  considered,  that  the 
amphibolitic  schists  were  originally  auriferous,  rather  in  respect 
of  gold-quartz  veins  than  in  disseminated  gold,  and  that,  having 
reached  by  simple  loading  and  by  flexure  considerable  depths, 
the  distribution  of  their  gold  was  modified  by  the  action  of  heated 
solutions.  The  granitic  intrusions  are  therefore  to  be  looked  upon 
rather  as  evidence  of  the  heat  prevailing  and  of  the  stress  to 
which  the  region  has  been  subjected  than  as  actual  carriers  of  gold. 
Their  heat  must  certainly  have  assisted  in  the  redistribution  of 
the  metalliferous  content.  A  rare  association  of  gold  and  garnet  is 
reported  from  the  Lockhart  and  other  mines.  Assays  of  clean 
garnet  from  the  former  mine  have  shown  a  value  of  nearly  £2. 
15s.  ($10.74).  Garnets  showing  free  gold  have  also  been  obtained.6 
It  is  not  difficult,  from  the  general  principles  of  metasomatic 
replacement,  to  construe  this  association  to  denote  a  deposition  of 
gold  in  situ  prior  to  the  formation  of  the  garnet,  followed  by 
contact-metamorphism  arising  from  the  granitic  intrusion. 

The  Lockhart  mine  is  typical  of  the  Dahlonega  occurrences. 
It  has  been  worked  successfully,  but  on  a  small  scale,  for   many 


°  Bull.  U.S.  Geo!.  Surv.,  No.  293,  1906,  p.  120. 
6  Becker,  loc.  cit.  sup.,  p.  297. 


590 


NORTH   AMERICA. 


years.  The  veins  lie  in  mica-schist  underlain  by  amphibolite. 
The  ore  occurs  in  shoots  or  lenticular  masses  of  quartz  in  the  mica- 
schist,  but  very  close  to  the  amphibolite  contact.  The  vein  is  some 
7  feet  wide,  consisting  of  lenticular  masses  of  quartz  intercalated 
within  the  lode  with  streaks  and  bands  of  a  gangue  consisting 
principally  of  garnet,  dark-green  mica,  and  hornblende.  Sulphides 
(pyrite,  chalcopyrite,  pyrrhotite,  and  galena)  occur  with  the  quartz. 
Most  of  the  gold  is  said  to  occur  native  in  the  reddish-brown  garnets." 
The  garnet-mica-hornblende  rock  is  considered  by  Lindgren  to  be  a 
replacement  of  the  original  country. 

The  Loud  mine,  11  miles  east  of  Dahlonega,  is  noted  for  its 
coarse  and  well-crystallized  gold,  often  reaching  800  in  fineness. 
Its  placer  deposits  are  among  the  richest   and  most  extensive    in 


Quartz.  Mica-garnet  rock.  Schist. 

Fro.  201.     Diagrammatic  section  across  Lockhart  Vein,  Dahlonega  (Lindgren). 

the  Southern  States.  Near  the  Nacoochee  Valley,  in  a  region  of  niica- 
and  hornblende-schists  with  numerous  granitic  dykes,  rich  alluvial 
ground  has  been  worked,  as  at  Duke's  Creek.  The  Boilston  mine, 
Henderson  County,  N.C.,  is  the  most  north-easterly  deposit  on  the 
Georgia  belt.  Here  a  large  dyke  of  granite  strikes  parallel  to  the 
vein  and  at  a  little  distance  away.  The  pay-ore  is  confined  to  small 
shoots  in  a  large  quartz  vein  often  20  feet  wide. 

The  South  Mountain  belt  of  western  North  Carolina  extends 
from  near  Morganton  south-south-west  to  the  vicinity  of  Ruther- 
fordton,  a  distance  of  some  25  miles.  Its  average  width  is  10  to  12 
miles.    The  rocks  of  the  mountain  svstem  are  Archaean  mica-  and 


°  Lindgren,  Bull.  U.S.  Geol.  Surv.,  No.  293,  1906,  p.  127. 


APPALACHIAN    STATES.  591 

hornblende-gneisses  and  schists  of  similar  character  to  those  of 
the  Georgia  belt.  The  auriferous  quartz  veins  form  a  system  of 
fissures  of  remarkable  regularity,  striking  always  east-north-east 
and  dipping  southward.  The  majority  are  thin  milky-quartz 
stringers  containing  pyrite,  galena,  chalcopyrite,  and  blende. 
Five  principal  zones  have  been  distinguished.  The  veins  are  as  a 
rule  too  small  to  admit  of  profitable  working,  but  they  have  furnished 
placer  deposits  that  have  been  attacked  from  time  to  time  with 
considerable   energy. 

The  Carolina  belt  is  the  most  extensive  and  most  productive 
of  the  Southern  Appalachian  belts.  It  lies  parallel  to  the  axis  of 
Appalachian  folding  but  is  far  to  the  east  of  the  higher  ranges.  It 
extends  from  the  Virginia  frontier  south-west  by  way  of  Monroe 
across  North  Carolina  into  South  Carolina.  Here  it  disappears  for 
a  short  distance  beneath  the  sediments  of  the  coastal  plain,  but 
reappears  in  Abbeville  County,  S.C.,  and  passes  into  Wilkes  County, 
Ga.  The  belt  is  10  to  40  miles  wide.  Its  auriferous  rocks  are 
(a)  argillaceous,  sericitic,  and  chloritic  metamorphosed  slates  and 
schists  ;  (6)  devitrified  ancient  volcanics  (rhyolite,  quartz-porphyry, 
and  pyroclastic  breccias  of  the  same)  ;  (c)  igneous  plutonic  rocks 
(granite,  diorite,  diabase,  &c.)  ;  (d)  siliceous  magnesian  limestone  ; 
(e)  sedimentary  pre- Jura-Trias  slates.  These  rocks  are  all  non- 
fossiliferous  and  must  be  provisionally  classed  as  Algonkian.  The 
belt  is  flanked  on  the  north-west  by  granites  and  gneisses,  and  on 
the  south-east  towards  the  coastal  plain  by  Jura-Trias  sandstones  and 
conglomerates  which  have  yielded  gold  in  insignificant  quantities." 
Auriferous  deposition  in  this  belt  is  believed  by  Becker b  to  have 
taken  place  at  the  close  of  the  great  Algonkian  volcanic  era ;  it  is  also 
believed  that  the  same  relation  holds  true  of  the  South  Mountain  and 
Georgia  belts.  Gold  deposition  was  seemingly  renewed  with 
diminished  activity  after  the  formation  of  the  Ocoee  series  and  the 
Monroe  Beds,  and  is  probably  to  be  attributed  to  the  heated  waters 
set  in  circulation  by  the  diabasic  intrusions  of  a  later  period. 

The  gold-ores  of  the  Carolina  belt  are  found  both  in  quartz 
fissure-veins  and  as  pyritous  impregnations,  the  latter  being  accom- 
panied by  irregular  stringers  and  lenticles  of  quartz  striking  with 
the  foliation  of  the  schists  and  the  lamination  of  the  slates.  The 
sulphides  are  ordinarily  pyrite,  chalcopyrite,  galena,  mispickel, 
and  blende.  The  tellurides,  nagyagite  and  tetradymite,  have  a  wide 
distribution,  but  are  nowhere  present  in  large  quantities. 

The  Carolina  belt  contains  several  workable  gold  occurrences 
of  which  the  Haile  and  Brewer  mines  in  South  Carolina,  and  the 

«  Nitze  and  Wilkens,  Bull.  N.C.  Geol.  Surv.,  X,  1897,  p.  15. 
b  Loc.  cit.,  p.  261. 


592 


NORTH    AMERICA. 


King's  Mountain  and  Colossus  mines  in  North  Carolina,  are  perhaps 
the  most  notable. 

Haile  Mine. — The  country  of  the  Haile  is  a  light-grey  quartz- 
sericite-schist,  very  hard  and  dense.  It  probably  is  a  member  of 
the  great  group  of  metamorphosed  Algonkian  volcanic  rocks 
described  by  G.  H.  Williams a  as  having  a  large  development  in 
eastern  North  America.  As  pointed  out  by  Becker  h  it  is  certainly  of 
volcanic  origin,  still  showing  flow-structure,  and  represents  an 
acid  rock.      The  determination  has  been  confirmed  by  Graton/ 


6a"  ren  ouert.   *e.i 


Fig.  202.     Sketch  Map  showing  principal  Oee-bodies,  Haile  Mine  (Nitze  and  Wilkens). 

A.  Beguelin  pit.     jB.  Chase  Hill  pits.     C.  New  Haile  pit.     D.  Old  Haile  pit.     E.  Bumalo  pit. 

F.  Red  Hill  pit. 

who  refers  the  rock  to  an  original  acid  porphyry-tuff .  The  bedding 
of  the  tuffs  is  in  some  places  still  well  preserved.  The  general  strike 
of  the  schists  is  north-east  to  east-north-east,  and  their  dip  from 
45°  to  80°  north-west.  The  Haile  mine  is  traversed  by  three 
approximately  vertical  olivine-diabase  dykes  crossing  the  schists 


"  Jour.  Gcol.,11,  1894,  p.  28. 

b  Loc.  cit.,  p.  307. 

'  Bull.  U.S.  Geol.  Surv.,  No.  293,  1906,  p.  16. 


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APPALACHIAN    STATES. 


593 


from  south-east  to  north-west,  as  shown  on  the  accompanying 
sketch.  Their  widths  are,  respectively,  27,  130,  and  192 
feet.  The  Haile  ore-bodies  are  lenses  of  silicified  tuff  impregnated 
with  auriferous  pyrite.  Silicification  and  pyritization  appear  to 
have  been  contemporaneous,  and  the  richness  of  the  ore  varies  in 
direct  proportion  to  the  degree  of  siliceous  replacement.  True 
quartz  veins  are  few  and  are  generally  worthless.  Molybdenite  is 
often  associated  with  the  pyrite.  Gold  occurs  free,  both  as  a 
primary  and  a  secondary  deposit  and  also  within  the  pyrite  crystals. 
The  ore-bodies  are  large  but  low-grade,  that  of  the  Haile  proper  being 
about  200  feet  long  and  disposed  for  about  100  feet  on  both  sides  of  a 
diabase  dyke.  The  width  of  the  ore-body  is  determined  solely  by  the 
values.  The  Bumalo  ore-body  to  the  east  of  the  Haile  is  about  250 
feet  long  by  40  feet  wide.    The  Beguelin  to  the  north-west  and  on 


Altered  volcanic  tuff 


Diabase 


Scale  cf 'feet 

200 


4  00 


Fig.  203.     Vertical  section  of  the  Beguelin  Ore-body,   Haile  Mine,  South  Carolina  (Graton)- 

the  course  of  the  two  main  dykes  is  much  larger,  carrying  ore  for  nearly 
300  feet  on  each  side  of  the  130-foot  dyke.  Recently,  the  energetic 
prospecting  drilling  carried  on  by  the  manager,  the  late  Mr.  E.  A. 
Thies,  disclosed  a  valuable  ore-body  further  north-west,  and  300  feet 
away  from  the  diabase  dyke.  This  ore-body  was  being  worked 
at  the  time  of  the  present  writer's  visit  to  the  mine  in  May,  1907. 
The  ore  is  decidedly  low-grade,  averaging,  as  sent  to  the  mill,  perhaps 
12s.  6d.  ($3.00)  per  ton.  The  total  costs  are  said  to  be  only  6s.  8d. 
($1.60)  per  ton.a  The  total  output  of  the  Haile  mine  to  1905  is 
estimated  at  about  £666,250  ($3,250,000).  The  mine  has  been 
worked  almost  continuously  since  1830,  and  in  the  early  days  of 
working  very  rich  ore  was  obtained  at  and  near  the  outcrops,  the 
result  obviously  of  secondary  enrichment. 


a  Graton,  loc.  cit.,  p.  8: 
Oi 


594  NORTH    AMERICA. 

Attacking  the  problem  with  an  obvious  bias  towards  the  hypothe- 
sis of  a  genetic  connection  between  auriferous  deposition  and  granitic 
magmas,  Graton  has  concluded a  that,  notwithstanding  the  relative 
positions  of  diabase  dykes  and  ore-bodies,  the  diabase  is  subsequent 
to  and  has  consequently  exercised  no  effect  on  the  deposition  of 
the  ore-bodies.  For  his  interesting  argument  in  support  of  his 
hypothesis,  which  can  be  fairly  quoted  only  in  extenso,  the  student  is 
referred  to  the  original  memoir.  The  result,  however,  of  the  present 
writer's  examination  of  the  mine  led  him  to  adopt  in  its  entirety 
the  hitherto  generally-accepted  assumption  that  the  Haile  ore-bodies 
were  directly  due  to  the  influence  of  the  diabasic  dykes  traversing 
the  mine.  It  may  further  be  mentioned  that  the  nearest  known  granite 
is  two  miles  away  from  the  pits.  The  Haile  mine  is  interesting  in 
another  respect  as  having  been  the  home  of  the  Thies  barrel- 
chlorination  process,  that,  until  the  introduction  of  cyanide  of 
potassium,  was  among  the  most  successful  of  lixiviation  processes. 

Brewer  Mine. — The  Brewer  mine  lies  10  miles  north-east  of 
the  Haile,  and  13  miles  north-east  of  Kershaw.  It  is  believed  to 
have  been  the  first  important  gold  producer  in  South  Carolina.  As 
at  the  Haile  the  first  operations  were  on  the  placer  deposits  of  the 
small  streams  of  the  neighbourhood.  The  rocks  and  the  ore  are 
practically  identical  with  those  of  the  Haile,  though  the  great 
amount  of  decomposition  makes  the  determination  of  the  character 
of  the  country  very  difficult.  A  diabase  dyke  lies  on  the  west  bank 
of  Flat  Creek  near  the  mine,  and  granite  intrusions  are  said  to  occur 
within  half  a  mile  of  the  ore-body.  The  ore  is  a  dense  blue  rock 
similar  to  that  of  the  Haile,  but  is  even  more  siliceous.  It  has  been 
formed  by  siliceous  impregnation  and  replacement,  and  is  now 
low-grade  in  depth.  The  Tan- Yard  placer  deposit  at  the  Brewer 
mine  was  for  long  the  richest  of  the  Southern  Appalachian  alluvial 
deposits. 

Colossus  Mine.— The  Colossus  mine  lies  in  Union  County,  N.C., 
some  four  miles  south  of  Waxhaw.  Its  geology  is  similar  to  that 
of  the  Haile,  25  miles  further  south.  Quartz-sericite-schists  intruded 
by  diabase  dykes  are  silicified  along  certain  bands.  The  ore  is  a 
dense  and  highly  siliceous  rock  impregnated  with  pyrite.  The 
ore  mined  is  on  the  whole  richer  than  that  of  the  Haile,  averaging 
some  £3  ($15.00)  per  ton.  The  greater  value  is  probably  due 
to  closer  selection. 

King's  Mountain. — The  King's  Mountain  mine,  Gaston 
County,  N.C.,  has  yielded  since  its  discovery  in  1834  about 
£184,500  ($900,000).     The  country  is  micaceous  schist  overlying 


a  Loc.  cit.,  p.  70. 


APPALACHIAN    STATES.  595 

a  schistose  impure  limestone  closely  associated  in  origin  with 
interlaminated  biotite-schist.  A  zone  of  graphite  and  pyrite  directly 
underlies  the  limestone.  A  granitic  dyke  is  reported  to  have  been 
met  with  in  the  workings.  The  valuable  ore  was  derived  in  the  past 
from  narrow  quartz  veinlets  and  stringers  in  the  upper  oxidised 
zone.  In  depth  the  ore  became  very  complex,  containing  free  gold, 
pyrite,  pyrrhotite,  chalcopyrite,  galena,  mispickel,  blende,  and 
tetrahedrite,  with  the  rare  minerals  nagyagite  (gold  telluride), 
altaite  (lead  telluride),  and  bismite.  Sericite  and  fluorite  form  gangue 
minerals  in  addition  to  quartz.  The  ore-bodies  are  said  to  have  been 
exceptionally  rich  at  the  limestone  contact. 

The  Iola  mine,  Montgomery  County,  N.C.,  is  one  of  the  most 
important  of  recently-opened  mines.  Its  yield  is  about  £24,000 
per  annum." 

Placers. — Placer  gold  in  the  Southern  Appalachians  is  found, 
as  elsewhere,  in  valley  bottoms  and  gravels.  Much  more  important 
than  the  stream  gravels  are  the  auriferous  deposits  resulting  from 
the  decomposition  and  disintegration  in  situ  of  impregnated  ore- 
bodies,  veins,  and  country.  For  such  loose  decomposed  rock  the 
term  saprolite  has  been  proposed  by  Becker. h  In  the  Southern 
States  decomposition  often  extends  to  a  depth  of  50  to  100  feet. 
When  the  decomposed  rock  has  been  seamed  by  auriferous  quartz 
veins,  little  of  the  gold  passes  into  the  streams,  and  the  great  bulk, 
falling  into  crevices,  remains  on  the  hillsides  to  materially  enhance 
the  value  of  the  surface  soil  and  rock.  The  quartz  of  the  original 
veins,  especially  when  it  has  contained  very  little  pyrite,  is  but 
slightly  disintegrated,  and  contains  gold.  To  obtain  such  gold 
the  so-called  Dahlonega  method  has  been  developed.  The  decom- 
posed rock  is  washed  by  water  under  pressure  into  sluices,  where 
the  quartz  is  caught  on  grizzlies  and  passed  through  amalgamating 
stamp-mills.  Amalgamation  is,  however,  often  ineffective  owing 
to  the  gold  being  coated  with  a  film  of  iron-oxide.  In  some  saprolites 
little  residual  quartz  is  found  with  the  gold.  The  gold  of  the  sapro- 
lites is  naturally  very  rough,  and,  in  some  cases,  as  at  the  Loud  mine 
near  Dahlonega,  masses  of  wire  gold  are  met  with.  For  such  occur- 
rences the  present  writer  suggests  a  secondary  origin,  akin  in 
operation  to  the  growth  of  nuggets  in  situ  or  to  the  secondary 
enrichments  of  vein  outcrops.  The  general  low-grade  of  the  ores 
in  depth  certainly  indicates  some  such  explanation  of  the  wide 
surface  enrichment.  In  addition  to  hydraulicking  by  the  Dahlonega 
method,  dredges  have  been  employed  to  work  the  gold  deposits 

a  Min.  Sci.  Press,  March  28,  1908. 
b  Loc.  cit.,  p.  289. 


596  NORTH    AMERICA. 

of  the  shallow  valleys  and  also  of  the  rivers,  and  have  been  of  late 
moderately  successful  on  the  Chestatee  river,  Lumpkin  County,. 
Georgia,  where  they  have  been  in  operation  for  many  years.  The 
earlier  dredges,  however,  having  been  built  before  the  broad 
principles  underlying  dredging  were  understood,  were  invariably 
failures. a 

Negro  miners,  when  working  the  saprolites  on  a  small  scale,, 
make  extensive  use  of  rockers  made  from  logs  hollowed  in  the  form 
of  a  rocking  cradle,  but  with  the  upper  end  alone  closed.  The 
length  of  the  rocker  is  from  5  to  10  feet.  Three  or  four  are  often  so 
joined  as  to  move  in  unison,  and  are  thus  worked  by  one  man  or 
woman.  A  reciprocating  motion  is  given  to  the  rocker  which, 
combined  with  the  inclination  at  which  it  is  set,  and  the  flow  of 
water  from  the  head,  gradually  works  off  the  lighter  materials. 

A  small  portion  of  the  North  Georgian  auriferous  belt  passes 
through  Polk  and  Monroe  counties  in  the  extreme  south-west  of 
Tennessee,  where  lenticular  veins  occur  in  the  pre-Cambrian  Ocoee 
slates.  The  Coco  Creek  placers  in  this  region  are  worked  by 
dredging.  These  deposits  have  been  known  since  1833.  Some 
portion  of  the  small  gold  yield  of  Tennessee  comes  from  the  famous 
Ducktown  copper  veins.  The  ores  from  these  contain  about  1-8 
per  cent,  copper,  while  the  copper  pig  produced  yields  from  0-02 
to  0-04  ounce  gold  per  ton.  Not  all  the  contained  gold  is  recovered, 
since  a  considerable  portion  of  the  copper  obtained  is  not  electro- 
lytically  refined. 


a  Eng.  Min.  Jour.,  Nov.  2,  1901. 


597 


CENTRAL   AMERICA  AND  WEST   INDIES. 


MEXICO. 


The  great  mineral-bearing  zones  of  Western  North  America 
are  continued  southward  into  Mexico.  The  Pacific  Coast  belt  has, 
it  is  true,  no  very  great  or  extensive  development,  but  the  hitherto 
subordinate  belt  of  south-western  Nevada  assumes  great  importance 
in  the  north-western  States  of  Sonora  and  Sinaloa,  while  the  later 
Tertiary  propylitic  zone  of  Colorado  loses  none  of  its  prominence 
on  reaching  the  southern  republic.  The  mineral  wealth  of  Mexico 
lies  rather  in  silver  than  in  gold,  but  its  production  of  the  latter 
metal  is  nevertheless  very  large.  For  many  years  it  has  occupied 
the  fourth  position  in  the  list  of  gold-producing  countries,  being 
surpassed  in  this  respect  by  the  Transvaal,  the  United  States, 
and  Australasia.  In  September,  1906,  there  were  in  the  republic 
1,572  gold  mines  (of  which  one-third  were  in  Sonora),  6,467  gold- 
silver  mines,  1,373  gold-silver-copper  mines,  1,317  gold-silver-lead 
mines,  and  262  gold-copper  mines.  It  will  therefore  be  abundantly 
apparent  that  much  of  the  gold  yield  of  Mexico  is  largely  a  by- 
product, and  that  it  fluctuates  with  the  demand  for  the  baser  metals, 
lead  and  copper.  The  most  notable  gold  producers  are  the  three 
mines  of  the  El  Oro  group  (Esperanza,  El  Oro,  and  Dos  Estrellas) 
lying  some  80  miles  west  of  Mexico  City,  and  the  Dolores  mine  in 
Western  Chihuahua.  The  Esperanza  mine  was  in  1906  the  first 
in  the  list  of  the  world's  gold  mines  both  in  respect  of  actual  output 
and  of  profit  earned,  producing  £1,580,321  ($7,708,883),  and  paying 
in  dividends  £952,077  ($4,644,279).  Its  place  was,  however,  taken 
in  1907  in  the  former  respect  by  the  Goldfield  Consolidated  (Gold- 
field,  Nevada),  and  in  the  latter  by  the  Robinson  Mines,  Transvaal. 

Gold  occurs  in  Mexico,  as  already  indicated,  in  simple  gold- 
quartz  veins,  in  silver-gold  veins,  and,  in  subordinate  quantity, 
in  copper  veins.  Veins  of  the  first  class  lie  for  the  most  part  in 
crystalline  or  metamorphic  schists,  pegmatites,  granites,  and  diorites, 
always  in  the  vicinity  of  recent  eruptives.  Examples  of  this  class 
are  found  most  abundantly  in  Lower  California  and  in  the  Pacific 
Coast  States  of  Sonora,  Sinaloa,  &c.  The  Lower  Calif ornian  zone 
may  be  considered  the  southern  continuation  of  the  Californian 
granodioritic  gold  belt.  The  auriferous  deposits  of  Sonora,  west 
of  the  Sierra  Madre,  apparently  belong  to  the  same  type  as  those 
developed  in  Arizona. 


598  CENTRAL    AMERICA. 

Gold-silver  veins  in  propylitic  rocks  are  numerous  and  show 
all  the  characteristics  of  such  veins.  Their  gangue  is  ordinarily 
quartz  with  subordinate  calcite,  accompanied  by  occasional  fluorite, 
gypsum,  and  rhodochrosite.  The  sulphide  minerals  occurring  in 
depth  are  pyrargyrite,  proustite,  miargyrite,  polybasite,  argentite, 
stibnite,  pyrite,  galena,  chalcopyrite,  and  a  little  blende.  Numerous 
veins  of  this  type  are  found  also  on  the  western  slopes  of  the  Sierra 
Madre,  but  they  attain  their  greatest  development  in  the  central 
southern  plateau,  where  lie  the  great  silver  mines  that  contributed 
so  largely  to  the  wealth  wrested  from  Mexico  by  the  Spaniards.  The 
famous  El  Oro  mines,  among  the  most  productive  of  recent  years, 
belong  to  this  type,  notwithstanding  the  fact  that  their  veins  lie  in 
Cretaceous  shales,  for  they  are  certainly  dependent  on  late  Miocene 
andesitic   intrusions  for  their  metalliferous  content. 

Contact  metamorphic  deposits  of  Lower  Tertiary  age  occur 
along  the  planes  of  contact  of  Cretaceous  limestone  and  diorite, 
especially  on  the  eastern  flanks  of  the  Sierra  Madre.  Examples  are  to 
be  seen  at  Encarnacion,  Hidalgo  ;  San  Jose  del  Oro,  Tamaulipas  ; 
Mazapil,  Zacatecas  ;   and  at  Santa  Fe,  Chiapas. a 

Numerous  veins  in  the  provinces  of  Sonora  and  Tepic,  are  in 
granulite  country.  In  Oaxaca  and  Jalisco  they  occur  in  diorites, 
and  in  Sinaloa  and  Guerrero  in  crystalline  schists.  These  veins  have 
a  quartz  matrix  and  are  generally  pyritous.  In  the  San  Cristobal 
mine,  Guerrero,  veins  pass  from  the  crystalline  schists  into  andesites 
where  they  contain  a  notably  greater  percentage  of  silver.  In  the 
Los  Ocotes  mine,  Sultepec  district,  State  of  Mexico,  veins  in  phyllite 
are  intimately  associated  with  pyroxene-andesite.  There  is  thus  a 
fairly  well-defined  zone&  lying  entirely  to  the  west  of  the  Sierra 
Madre  mountains  in  which  the  veins  are  in  the  older  rocks  (granite 
and  crystalline  schists),  and  are  probably  of  Lower  Cretaceous  or 
Early  Tertiary  age,  owing  their  mineralisation  to  intrusions  of  this 
age.  This  belt  or  zone  is  continued  northwards,  as  has  been  seen, 
into  the  south-western  part  of  New  Mexico. 

The  mineral  zones  of  Mexico  are  among  the  richest  in  the 
world.  The  veins  are  perhaps  most  numerous  along  the  western 
range  of  the  Sierra  Madre,  but  the  largest  and  richest  have  been 
found  in  the  Central  Plateau  region.  The  veins  occur  always  in 
connection  with  volcanic  rocks.  Gold,  unaccompanied  by  silver, 
is  found  mainly  in  the  crystalline  gneisses  and  schists  that  outcrop 
in  the  low  country  towards  the  Pacific  Coast.  The  largest  (mainly 
silver)  deposits  are  in  the  Upper  Mesozoic  sediments  (Cretaceous 

a  Ordonez,  Mem.  y  Rev.  Soc.  cient.  "Ant.  Alzate,"  XI,  1897,  p.  216  ;  Aguilera,  Trans. 
Amer.  Inst,  M.E.,  XXXIII,  1902,  p.  517. 

°  Sonoran  of  Merrill,  loc.  cit.  inf. 


MEXICO. 


599 


limestones,  shales,  and  slates)  intruded  and  accompanied  by 
numerous  volcanic  dykes  and  flows. a 

The  yield  of  gold  in  Mexico  is  steadily  increasing.  Its 
production,  since  it  is  often  merely  a  by-product,  is  largely  pro- 
portional to  that  of  the  baser  metals,  silver,  copper,  and  lead. 

Exact  figures  of  the  total  gold  output  of  Mexico  are,  of  course, 
unattainable.  It  is,  however,  estimated  by  Lindgren&  at  at  least 
£37,043,500  ($180,700,000)  from  1690  to  1900  inclusive.  Since  the 
latter  year  it  has  been  as  follows  :  — 


Year. 

Kg- 

Crude  Ounces. 

Value,  Dollars. 

Value,  Sterling. 

1901 

13,458 

432,674 

$9,089,800 

£1,863,409 

1902 

13,792 

443,412 

9,315,257 

1,909,627 

1903 

15,134 

466,558 

10,222,318 

2,095,575 

1904 

17,518 

563,203 

25,842,563* 

2,584,256 

1905 

23,599 

758,707 

31,793,841* 

3,179,384 

1906 

20,247 

650,941 

13,174,331 

2,699,658 

*  Mexican  dollars  or  pesos. 

Lower  California. — The  Lower  Californian  goldfields  may 
be  considered  the  most  southerly  members  of  the  great  Pacific 
belt  of  Cretaceous  veins,  best  exemplified  by  the  Mother  Lode  of 
California.  Thus  the  mines  of  Santa  Clara,  Real  del  Castillo,  El 
Alamo,  Camalmahi,  and  San  Borja  are  all  in  granite  country.  Their 
gold  is  associated  with  quartz,  auriferous  pyrite,  and  copper  sulphides. 

In  Lower  California  the  principal  auriferous  region  is  Alamo, 
originally  a  placer  field,  and  discovered  about  1889.  The  district 
is  70  miles  east  of  La  Encinada.  The  mines  lie  in  the  Alamo  basin. 
The  rock  of  the  region  is  granite,  traversed  by  diorite  dykes. c 

In  the  Viznaga  mine  gold  occurs  in  lenticular  quartz  varying 
in  width  from  6  to  18  feet.  The  workings  here  reach  a  depth  of  more 
than  400  feet.     Very  rich  pockets  are  occasionally  found.^ 

Sonora. — The  district  of  Sonora  has  long  been  prominent 
for  the  great  number  of  its  ancient  gold  mines,  generically  termed 
antiguas,  many  of  which  have  been  abandoned  since  the  War  of 
Independence  of  1810,  or  were  exhausted  even  before  that  date,  for 
the  mining  industry  had  then  been  in  existence  in  Sonora  for  nearly 
three  centuries.  The  district  is  the  southern  continuation  of  the 
Arizona  desert  and  present  the  same  characteristic  features— a  sandy 


a  Merrill,  Eng.  Min.  Jour.,  Ap.  G,  1907,  p.  667. 

b  Trans.  Amer.  Inst.  M.E.,  XXXIII,  1903,  p.  844. 

c  Wankowski,  Mines  and  Minerals,  June,  1901,  p.  507. 

d  Trentini,  "  El  Floreceimento  de  Mexico,"  Mexico,  1906,  Vol.  II,  Eng.  Ed. 


600  CENTRAL    AMERICA. 

plateau,  at  an  elevation  of  some  2,000  feet,  from  the  level  of  which 
isolated  granite  peaks  or  short  granite  ranges  rise.  The  oldest  rocks 
are  granites  and  gneiss  overlain  by  Palaeozoic  (Cambrian  to  Carboni- 
ferous) limestones  and  quartzites,  on  which  Triassic  beds,  containing 
coal  and  graphite,  rest.  Cretaceous  limestones  and  shales 
are  exposed  in  the  central  region  of  Sonora  and  often  carry  copper 
deposits.  The  latest  deposits  of  the  region  are  the  great  volcanic 
lavas  and  tuffs  of  quartz-porphyry,  rhyolite,  dacite,  and  andesite, 
that  contain  so  many  of  the  more  important  ore-bodies.a 

Extensive  dry  placers  occur  in  the  Altar  district  near  La 
Cienaga  and  Palomas.  These  have  yielded  hundreds  of  thousands 
of  ounces  to  the  dry-pan.  The  Altar  region  has  also  been  long  noted 
for  rich  gold-quartz  veins,  of  which  El  Tiro  vein  and  the  Cerro 
Colorado  Hill,  near  La  Cienaga,  have  been  the  most  productive. 

The  gold-quartz  veins  of  the  Sierra  Pinta  del  Bajio,  Altar 
district,  lie  in  pegmatites  intrusive  into  metamorphic  schists. 
These  carry  also  auriferous  pyrite  and  chalcopyrite  with  minor 
galena  and  blende.  The  Altar  region  was  the  chief  source  of  the 
gold  supply  of  the  Aztecs,  of  the  conquistador -es,  and  of  the  later 
Spaniards. 

East  of  Altar  is  the  Magdalena  district,  containing  numerous 
ancient  gold  mines,  many  of  which  are  now  being  opened  anew. 
The  mines  of  the  Sierra  Pinitos  lie  a  few  miles  south  and  south-east 
of  Nogales  on  the  Arizona  frontier.  Their  ore-bodies  are  quartz  veins 
carrying  gold.  Several  of  the  deposits  occur  on  the  contact  between 
the  prevailing  andesitic  rock  and  an  intrusive  dacite.  Others  are 
fissure  veins  filled  with  shattered  and  altered  andesite  and  with 
long  thin  lenses  of  white  or  rusty  quartz.  The  gold  veins  vary 
from  5  to  7  feet  in  thickness,  and  carry  low  values  in  the  altered 
and  pyritized  country.6  The  Sierra  Azul  mines  lie  on  the  eastern  edge 
of  the  Magdalena  district.  Their  auriferous  ore-deposits  are  quartz 
veins  in  granite.  The  ore  lies  often  in  a  vein-filling  of  brecciated 
granite.  The  Cerro  Prieto,  30  miles  south-east  of  Magdalena,  is 
one  of  the  most  extensive  of  the  antiguas  in  the  country.  It  is  now 
being  worked  by  the  Black  Mountain  Company  (Chicago)  with  120 
stamps.  An  enumeration  of  the  names  alone  of  the  antiguas  of 
these  districts  would  occupy  pages. 

Arizpe,  the  next  district  to  the  east  in  Sonora,  is  famous  rather 
for  its  copper  camps  (as  Cananea)  than  for  gold.  The  old  Santa 
Rosalia  gold  mine,  famous  in  former  days,  lies  to  the  north-east  of 
Cerro  Prieto.  El  Tigre  is  the  best  known  gold  and  silver  mine  in  the 
Moctezuma  district.     In  Ures  district  is  the  San  Ricardo,  a  formerly 


"  Merrill.  Min.  Sci.  Press,  Jan.  4,  1908,  p.  33. 

b  Weed,  Trans.  Am.  Inst.  M.E.,  XXXII,  1902,  p.  428. 


MEXICO. 


601 


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602 


CENTRAL    AMERICA. 


rich  gold  mine  that  was  escheated  to  the  Mexican  Government 
from  American  owners  for  smuggling  gold  out  of  the  country  in 
onler  to  evade  royalty.  The  most  important  mining  camp  in 
Hermosillo  district  and  the  largest  gold  camp  in  Sonora  is  Minas 
Prietas.  Its  mines  were  long  worked  in  Mexican  fashion,  but  are 
now  controlled  by  American  capital  and  are  worked  successfully 
by  modern  methods. 

Sonora  was  overrun  by  Apache  Indians  from  the  time  of  the 
revolution  against  Spain  until  the  capture  of  the  notorious  Geronimo 
in  1884.  Since  then  it  has  been  vigorously  prospected  and  numerous 
antiguas  have  been  re-opened.  Gold  occurs  usually  in  small  cpian- 
tities  in  the  copper  ores  of  Sonora,  the  free  gold-cpiartz  veins 
occurring  chiefly  in  the  Altar  district.  The  zone  of  oxidation  in 
Sonora  is  usually  very  deep.  Vein-filling  occurs  principally  in 
shear-zones,    with    attendant    splittings,    horses,    &c. 


Fig.  205.     Guadalupe  y  Calvo  (Weed). 

Chihuahua — The  Descubidoro  mine,  a  few  miles  north  of 
the  town  of  Chihuahua,  lies  in  limestone  almost  entirely  surrounded 
by  volcanic  rocks  (andesites  and  rhyolites).  The  ore-bearing  zone 
is  about  40  feet  thick,  and  dips  at  8°  to  10°  south-east.  The  ore  occurs 
in  brecciated  cherty  patches  through  the  limestone,  and  is  generally 
associated  with  earthy  manganese  ore,a  carrying  about  12  ounces 
silver  and  0*3  ounce  gold  per  ton.  Free  gold  also  occurs  locally 
in  the  siliceous  portions  of  the  rock.6 


a  Cf.  Pilgrim's  Rest,  Transvaal,  and  Rico,  Colorado. 
b  Lakes,  Mines,  and  Minerals,  May,  1903,  p.  447. 


MEXICO.  603 

The  Guadalupe  y  Calvo  mines  in  the  south-west  corner  of 
Chihuahua  are  among  the  most  famous  in  Mexico  for  their  production 
of  gold  in  former  days.  The  gold  occurs  in  fissure  veins  traversing 
altered  and  fractured  andesitic  rocks.  Veins  are  not  found  in  the 
younger  rhyolites,  but  are  restricted  to  the  light-coloured  chalky- 
white  or  pink  porphyry-tuffs.  The  principal  mines  are  the  Rosaria 
and  the  Independencia.  The  former  is  a  huge  vein  60  to  150  feet 
wide,  averaging  perhaps  100  feet,  and  dipping  with  the  hillside 
so  that  it  yields  a  conspicuously  exposed  hanging-wall.  Four 
distinct  ore-shoots  separated  by  low-grade  quartz  have  been  worked. 
It  has  been  mined  since  1835.  The  early  yield  was  so  great  that 
a  mint  was  established  at  the  mine.  The  value  of  the  total  output 
from  1838  to  1847  is  estimated  at  £8,000,000  ($40,000,000).^  The 
Independencia  veins  in  the  same  locality  lie  in  an  andesite  that  is 
associated  with  intrusive  dacite.  They  are  considered  by  Weed 
to  be  replacement  veins.  The  La  Cumbre  mines,  further  west  near 
the  Sinaloa  frontier,  are  in  andesites,  altered  breccias,  and  lava 
flows.  Their  quartz  veins  also  were  formed  before  the  deposition 
of  the  rhyolite.  They  are  well-defined  reefs  with  bold  outcrops, 
and  contain  much  pyrite,  the  sulphide  zone  commencing  at  a  very 
short  distance  below  the  surface.^ 

Numerous  old  gold-districts,  some  of  which  are  now  being 
re-opened,  lie  near  Parral  in  the  south-west. 

The  Lluvia  de  Oro  mine  is  also  in  the  west  of  Chihuahua, 
about  5  miles  from  the  Sinaloa  boundary,  near  the  Rio  Fuerte. 
Though  long  known  to  the  Indians,  it  was  discovered  by  the 
Mexicans  only  in  1900;  two  years  later  it  was  bought  by  an 
American  company  for  £358,750  ($1,750,000).  It  owes  its  name 
("  Shower  of  Gold  ")  to  the  extraordinary  richness  of  its  outcrop. 
It  has  a  present  output  of  some  £16,400  ($80,000)  per  month. 
The  ore-bodies  occur  along  an  escarpment  of  Jurassic  limestone 
that  has  been  intruded  by  diabase  and  raised  by  faulting  about 
2,300  feet.  The  diabase  now  underlying  is  believed  to  be  at  least 
4,000  feet  in  thickness.  Eruptions  of  rhyolite  later  than  the  diabase 
have  been  of  frequent  occurrence,  one,  indeed,  occupying,  as  shown 
in  the  accompanying  sketch,  the  plane  of  the  great  fault. 
The  ore-bodies  are  metasomatic  replacements  of  the  limestone  with 
quartz.  They  are  confined  to  the  limestone  and  occur  in  irregular 
lenses  along  zones  of  sheeting  parallel  to  the  fault  system  of  the 
district,  and  transverse  to  the  bedding.  Thus  they  differ  from  the 
Mercur  and  Pilgrim's  Rest  occurrences  which  lie  parallel  with  the 


a  Weed,  loc.  cit.  sup.,  p.  408. 
^  Idem,  loc.  cit.,  p.  426. 


604 


CENTRAL    AMERICA. 


bedding.  The  ore  is  a  solid  grey  cherty  quartz  with  little  pyrite. 
Average  ore  in  depth  gave  3  ounces  gold  and  30  ounces  silver  per 
ton.    At  the  surface  it  was  much  richer. a 

The  Dolores  mine,  next  to  the  El  Oro  group,  perhaps  the  most 
productive  of  the  gold  mines  of  Mexico,  lies  on  the  western  slope 
of  the  Sierra  Madre  in  the  Tutuaca  Valley,  due  west  of  Chihuahua 
and  on  the  Sonora  border.  It  is  in  an  extremely  isolated  part  of 
the  State,  is  more  than  100  miles  from  a  railway,  and  may  be  reached 
only  by  rough  mule  trails.  The  country  is  diabase  greatly  intruded 
by   dykes    that   are   partly    responsible   for  the  zones  of  shearing 


Uuvio  de  Oro  Mine 


A         A. 


•V        "> 


jjffg  RadTuff-Aqqlomerafe  \?:p$    Gray  Tuff.  Ao^lomerafe 

ETT^|  Quartz-ande6ite  FvTl   Dark  Andesite 

F^r]  Limestone        ^^   Shale         FjFfj    Sandstone 

£3  Diabase            /   Rhyolite 
_   IK.  miles _    _   — 


Fig.  206.     Geological  section  of  the  Lluvia  de  Oko  district  (Burrows). 

that  constitute  the  auriferous  belts  of  the  district.  The  largest 
of  the  old  workings  is  on  the  Alma  de  Maria  zone,  but  two  other 
zones  (San  Francisco  and  Barrow)  are  also  worked.* 

Other  camps  in  the  same  neighbourhood,  but  further  south, 
are  the  Ocampo,  Pinos  Altos,  and  Soyopa.  Ocampo  was  discovered 
in  1821,  and  has  produced  several  rich  gold  mines,  the  Watterson 
being  the  most  notable  of  recent  times.  The  country  of  the  neigh- 
bourhood of  the  Ocampo  gold-silver  quartz  veins  is  rhyolite, 
andesite,   diabase,  rhyolite  tuff,  and  breccias.0 

Durango. — In  Durango  the  Inde  gold  mines  are  the  best 
known.    Thev  lie  in  the  north  of  the  State. 


a  Burrows,  Min.  Sci.  Press,  May  25,  1907,  p.  664. 
b  Farish,  Eng.  Min.  Jour.,  May  4,  1907,  p.  849. 
c  Bagg,  Min.  Sci.  Press,  Aug.  8,  1908,  p.  188. 


MEXICO.  605 

Hidalgo.— The  celebrated  mines  of  the  Pachuca  district  yield 
silver  with  very  little  gold.  The  veins  lie  in  a  complex  of  Tertiary 
volcanics,  the  principal  member  being  a  pyroxene-andesite,  with  which 
is  associated  rhyolite  and  basalt,  the  last  being  always  barren. 
The  silver  ores  occur  as  sulphides  and  are  associated  with  pyrite, 
galena,  blende,  stephanite,  and  polybasite.  The  veins  are  simply- 
filled  fissures.  Silicification  and  pyritization  has  gone  on  in  the 
adjacent  country  to  a  considerable  extent.  The  general  conditions 
therefore  much  resemble  those  of  the  Comstock  in  Nevada. 

Mexico. — The  famous  El  Oro  mines  are  90  miles  north-west 
of  Mexico  City  on  the  Michoacan  border.  The  mines  are  situated 
on  the  slope  of  a  ridge  rising  600  feet  above  the  valley.  On  the 
eastern  side  of  the  ridge  are  the  Mexico,  Esperanza,  and  El  Oro 
mines,  and  on  the  western  side  the  Dos  Estrellas,  the  last  being  in  the 
State  of  Michoacan.  The  country  consists  of  Cretaceous  shales 
covered  by  late  Tertiary  andesites.  The  shale  is  thinly  laminated, 
black,  and  calcareous  ;  it  contains  occasional  layers  of  limestone, 
and  is  intruded  in  many  places  by  andesite  stocks  of  apparently 
the  same  magma  as  that  which  furnished  the  overlying  flow. 
There  are  also  andesitic  intrusions  of  an  older  date.  Rickard" 
summarises  the  geological  sequence  of  events  as  follows  :  — 

(1)  Deposition  of  shale. 

(2)  Intrusion  of  andesite  as  dykes  and  sills. 

(3)  Successive  faulting,  with  formation  of  San  Rafael  lode. 

(4)  Ore  deposition. 

(5)  Eruption  of  younger  andesite. 

(6)  Cross  faults. 

The  period  of  vein-formation  appears  to  have  been  inter- 
mediate in  time  between  the  two  andesitic  intrusions.  In  some 
places  ore  has  been  found  in  the  older  andesite,  but  only  when 
adjacent  to  an  ore-body  in  the  shales.  The  lode  consists  of  a  broad 
zone,  80  feet  wide,  of  banded  quartz  veins  with  intervening  country, 
the  veins  being  formed  largely  by  siliceous  replacement  of  brecciated 
country.  The  ore  occurs  in  pay-streaks  along  the  walls  of  the 
veins.  The  largest  ore-bodies  lie  on  the  footwall  and  hanging- wall 
respectively,  and  are  connected  by  cross  stringers.  The  shale 
and  the  veins  have  obviously,  as  may  be  seen  from  the 
accompanying  section,  undergone  considerable  erosion  before 
the  deposition  of  the  later  andesite.  The  apex  of  the  vein  did  not 
in  all  places  reach  the  old  eroded  surface  of  the  shale,  in  these  cases 
fraying  out  some  depth  below  the  old  surface.     The  pay-ore  is  not 


"  Rickard,  T.A.,  Min.  Sci.  Press,  Sept.  22,  1906,  p.  352. 


£06  CENTRAL    AMERICA. 

confined  to  any  particular  vein  in  the  zone.  The  main  lode-channel 
is  faulted  by  a  fairly  parallel  series  of  faults  dipping  north  65°  to  70°. 

The  San  Rafael  Lode  is  the  main  lode  of  the  Mexico,  Esperanza, 
and  El  Oro  mines.  It  follows  a  great  fault  line,  and  is  itself  faulted. 
The  lateral  displacement  caused  by  the  later  fault  is  130  feet,  the 
vertical  500  feet.  Other  Esperanza  ore-bodies  (in  the  Esperanza  mine) 
are  the  West  vein,  which  opened  up  a  roughly  lenticular  pay-shoot  680 
feet  long,  9  feet  wide,  carrying  2-4  ounces  or  75  grammes  gold 
($49.70)  and  37  ounces  or  1,150  grammes  silver  ($19.55)  per  ton. 
Small  bands  of  shale  included  within  the  quartz  assayed  equally 
well.  The  ore  itself  is  beautifully  ribboned  ;  minute  crystals  of 
pyrite  encrust  the  quartz,  especially  in  geodes  and  vughs,  while  the 
richest  ore  contains  magnetite.  The  gold  is  free  and  in  fine  particles ; 
is  rarely  visible ;  and  is  associated  with  argentite  in  the  lower 
levels.  The  ore,  both  in  andesite  and  in  shale,  is  a  siliceous 
replacement  of  the  country.  The  andesite  country  near  the  vein 
often  contains  silver  and  traces  of  gold  on  assay. 

The  West  vein  of  the  El  Oro,  90  feet  west  of  the  San  Rafael, 
is  small,  rich,  and  unoxidised,  while  the  great  San  Rafael  lode  is 
oxidised  to  great  depths.  At  the  1,050-foot  level,  however,  a  rich 
body  of  sulphide-ore  worth  £8  ($40)  per  tona  has  been  struck  in 
the  San  Rafael  lode,  giving  a  new  lease  of  life  to  the  mine,  which 
had  formerly  been  rather  poor.  The  total  depth  attained  by  January, 
1908,  at  the  El  Oro  mine,  was  1,150  feet.  In  the  oxidised  ore  the 
ratio  of  the  gold  to  silver  was  1  to  6 J,  and  in  the  sulphide  ore,  1 
to  15,  the  ratios  in  both  being  fairly  constant. 

The  Somera  mine  is  on  the  dip  of  the  great  San  Rafael  lode, 
but  has,  by  arrangement,  no  rights  over  that  lode  on  the 
dip.  On  another  lode  is  the  Dos  Estrellas,  the  third  great  mine 
at  El  Oro.  Its  lode  is  divided  into  two  portions,  one  3  to  5  feet 
thick,  with  rich  bodies  of  ore  in  it,  and  beyond  it  another  vein  40 
feet  thick  with  12  dwts.  ore. 

In  1906  the  three  El  Oro  properties  produced  more  than 
£1,200,000  ($12,000,000  Mexican)  of  which  80  per  cent,  of  the  value 
was  from  gold.  The  Esperanza  is  one  of  the  most  productive  of 
the  world's  goldmines,  producing  $400,000  per  month.  In  1905, 
the  monthly  yield  was  over  a  million  dollars,  thus  contributed  : — 

Esperanza §650,000 

El  Oro $200,000 

Dos  Estrellas        $240,000 

Electricity  for  the  mines  is  brought  from  a  distance  of  176 
miles,  or  from  100  miles  beyond  Mexico  City. 


a  Min.  Jour.,  Oct.  26,  1907. 


MEXICO. 


607 


San  Luis  Potosi.— The  country  of  the  San  Pedro  district 
is  andesite,  underlying  and  probably  intrusive  into  a  limestone, 
which  is  capped  on  the  higher  summits  by  rhyolite.  The  rhyolite 
is  barren,  the  ores  occurring  at  limestone-andesite  contacts 
or  in  the  limestone  near  the  andesite.  Veins  in  the  andesite  itself 
are  ordinarily  small  and  barren.  The  ores  carry  both  gold  and 
silver,  free  gold  having  been  found  in  masses  from  300  to  350  ounces 
in  weight. a     The  gold-ore  mined  in  the  upper  levels  is  haematite-chert 


Fig.  207.    Longitudinal  section,  El  Oro  Mine. 

carrying  large  quantities  of  free  and  visible  gold  with  little  silver. 
In  depth  the  ores  are  generally  cherty  and  are  low  in  gold  and  high 
in  silver.  Samples  of  the  andesite  country  on  analysis  gave  2 
grammes  gold  and  20  grammes  silver  per  metric  ton. 

Guanajuato.— The  vein  systems  of  the  Guanajuato  State 
are  three,  viz.,  the  Sierra,  Veta  Madre,  and  La  Luz.  They  furnish 
mainly  silver  mines,  the  output  of  gold  being  comparatively  insig- 
nificant. The  proportion  of  gold  to  silver  in  weight  is  only  about 
1  to  250.     The  Pinguico  is  a  fault  vein  entirely  in  rhyolite    in  the 


°  Laird,  Trans.  Am.  Inst.  M.E.,  XXXV,  1905,  p.  863. 


608  CENTRAL    AMERICA. 

hanging-wall  of  the  great  Veta  Madre,  and  is  one  of  the  few  Mexican 
mines  discovered  in  recent  years.  The  country  of  the  Veta  Madre 
is  not  uniform,  schists,  agglomerates,  andesite,  and  rhyolite  occurring 
at  various  points.  The  thickness  of  the  rhyolite  near  the  Pinguico 
vein  is  from  1,500  to  1,700  feet.  The  vein  is  17  feet  wide  on  an 
average,  with  a  value  of  £7.  10s.  ( $36.00)  per  ton/' 

The  veins  of  La  Luz  are  of  great  length.  They  traverse  the 
La  Luz  (Cretaceous)  schists  for  7,200  feet,  and  may  be  traced  for 
4,000  feet  further  in  the  adjacent  granite.  The  ore-bodies  are  formed 
by  the  local  union  of  the  numerous  stringers  ("  ramaleos  ")  that 
lie  along  the  ore-zone.  The  La  Luz  mine  from  1843  to  1856  (14 
years)  is  estimated  to  have  produced  £8,200,000  ($40,000,000) 
gold  and  silver.  The  value  of  the  production  of  the  whole  district 
is  estimated  at  £22,960,000  ($112,000,000).^ 

Chiapas. — At  the  Santa  Fe  mine  in  Chiapas,  Southern  Mexico, 
gold  is  found  associated  with  bornite  lying  in  a  gangue  of  wollastonite. 
The  bornite  has  an  average  value  in  gold  of  an  ounce  per  ton,  and  in 
silver  60  ounces  per  ton.  Free  gold  is  found  in  the  upper  portions 
of  the  vein.  It  is  also  found  with  a  sulphide  of  nickel,  cobalt, 
iron,  and  copper,  akin  to  linnaeite.c  The  deposit  is  in  massive 
wollastonite  (silicate  of  lime)  apparently  due  to  local  thermo-  and 
dynamo-metamorphism  arising  from  the  intrusion  of  the  igneous 
rocks  that  are  found  in  the  mine.  Schistose,  garnetiferous,  and 
quartzose  rocks  are  met  with  in  the  neighbourhood.  The  ore-bodies 
occur  irregularly  disposed  in  the  wollastonite  matrix,  and  are 
largely  associated  with  garnet.^ 


GUATEMALA. 

Tradition  places  a  famous  ancient  gold  mine  in  the  mountains 
of  Illon,  department  of  Quiche,  Guatemala  Republic.  It  is  said 
to  have  been  worked  hy  the  Jesuits,  and  numerous  references  to  it 
are  made  in  ancient  ecclesiastical  records.  All  recent  attempts 
to  rediscover  the  mine  have  failed. 

The  only  placers  of  present  importance  in  Guatemala  are  those 
of  Las  Quebradas,  15  miles  from  Morales,  and  near  the  banks  of 
the  Motagua,  or  Rio  Grande,  flowing  north-east  into  the  Gulf  of 
Honduras.  The  placers  of  the  Yzabal  department,  in  which  is 
situated  Las  Quebradas,  were  a  source  of  great  revenue  to  the 
Spaniards  between  1627  and  1820/       The  gravel  deposits  of  Las 

"  Church,  Eng.  Min.  Jour.,  Nov.  24,  1906,  p.  960. 
6  Idem,  ib.,  July  27,  1907,  p.  153. 
c  Collins,  Trans.  Inst.  Min.  Met.,  VIII,  1900,  p.  303. 
d  McCarthy,  E.  T.,  ib.,  IV,  1896,  p.  169. 
"  Guatemala,"  Bureau  of  American  Republics,  Washington,  Xo.  32.  1892. 


GUATEMALA. 


609 


Quebradas  are  now  being  worked  by  hydraulic  methods,  and  are 
yielding  a  profit.  Three  monitors  are  employed.  The  surface 
gravels  carry  about  5  grains,  the  pay-streak  from  2  dwts.  to  9  dwts. 
per  cubic  yard.a 

BRITISH    HONDURAS. 

Auriferous  quartz  veins  are  reported  from  the  broken 
mountainous  region  between  Garbutt's  Falls  on  the  Belsize  river  and 
the  sea-coast  at  Deep  river.  The  value  of  these  veins  is  unknown, 
as  also  is  the  geology  of  the  country  in  which  they  occur.& 


SALVADOR. 


Very  little  information  is  available  regarding  the  mineral 
wealth  of  this  republic.  Gold-quartz  veins  occur,  but  the  principal 
metal  mined  is  silver.  The  country  rocks,  so  far  as  they  are  known, 
are  ancient  eruptives.  The  gangue  of  the  veins  is  largely  calcite. 
The  disposition  of  gold  is  extremely  capricious,  and  the  metal  is 
obtained  merely  as  a  by-product  of  the  silver  mines. c 

Numerous  small  gold  mines  are  known  ;  as  those  of  Pepita  de 
Oro,  in  the  Department  of  Cabanas  ;  of  El  Porvenir,  south-west 
of  Sesuntepeque  ;  of  San  Sebastian,  in  the  Department  of  La 
Union  ;    of  La  Poza  and  others  in  the  Department  of  San  Miguel.^ 

The  following  is  an  estimate  of  the  gold  production  of  Salvador 
from  1901   to   1906  :— 


Year. 

Pesos. 

Sterling. 

1901 

53,467 

£5,346 

1902 

4,000 

400 

1903 

30,144 

3,014 

1901 

16,127 

1,612 

1905 

652,568 

65,256 

1906 

2,662,092 

266,209 

HONDURAS. 

Of  the  six  minor  Central  American  States  Honduras  is  the 
richest  in  mineral  wealth.  Its  gold  deposits  were  known  to  Columbus 
who,  on  his  arrival  on  the  coast  in  1502,  was  informed  of  the  golden 
sands  of  the  streams  of  the  interior.  Not  long  after,  the  placers  of 
the  Olancho  department  were  discovered  and  worked  by  the  famous 
conquistador,  Gil  Gonzalez  Davila,  who  obtained  as  his  reward 
120,000  golden  crowns  (perhaps  £48,000).    There  are  no  exact  records 

a  Eng.  Min.  Jour.,  Aug.  25,  1904,  p.  302  ;  lb.,  June  13,  1908. 
b  Bristowe,  "  Handbook  of  British  Honduras,"  1892,  p.  17. 
c  Annales  del  Museo  Nacional,  San  Salvador,  I,  1904,  pp.  328,  424. 
d  Barbarena,  Eng.  Min.  Jour.,  Ap.  18,  1908,  p.  810. 
Pi 


610 


CENTRAL    AMERICA. 


of  the  yield  of  the  mines  of  Honduras  during  Spanish  rule,  but 
the  royal  fifth  (quinto)  in  the  year  1594  is  said  to  have  amounted 
to  1|  million  piastres  (£300,000).  In  the  beginning  of  the  seven- 
teenth century  the  exceedingly  rich  placers  of  El  Clavo  Rico,  at 
El  Corpus,  department  of  Choluteca,  were  discovered.  Their  gold 
was  very  coarse  and  nuggets  were  numerous.  With  the  promulgation 
of  the  edict  of  1729  prohibiting  the  employment  of  forced  labour 
many  mines  were  abandoned,  but  the  gold  industry,  as  a  whole, 
flourished  for  many  years  longer,  and  commenced  to  decline  only 
in  the  early  years  of  the  nineteenth  century,  when  Central  America 
was  given  over  to  internecine  warfare.  During  the  last  15  years  a 
revival  in  Honduras  mining  has  taken  place,  largely  owing  to  the 
introduction  of  foreign  capital. 

Gold-quartz  veins  occur  both  on  the  Caribbean  and  on  the 
Pacific  slopes.  On  the  former  slope  the  veins  are  of  minor  importance. 
They  occur,  as  at  Santa  Cruz,  in  foliated  gneiss,  mica-schist,  and 
talcose  schist,  through  which  penetrate  numerous  hornblende- 
diorite  dykes. a  On  the  Pacific  side  the  country  of  the  veins  is 
Tertiary  andesite  and  associated  volcanic  rocks.  The  veins  in  these 
rocks  show  all  the  irregularities  characteristic  of  andesitic  quartz 
veins.  The  common  associates  of  the  silver-gold,  for  the  gold  content 
is  here  comparatively  unimportant,  are  pyrite,  galena,  and  blende. 
The  most  important  enterprise  at  the  present  time  is  the  Rosario 
silver-gold  mine,  in  the  San  Juan  mountains,  21  miles  from 
Tegucigalpa.  The  production  of  this  mine  in  1903  was  about 
£180,000  ($900,000)  and  it  had  in  18  years  distributed  nearly 
£400,000  ($2,000,000)  in  dividends.  The  Aramecina  mine,  Valle 
department,  also  giving  a  silver-gold  product,  has  likewise  had  a 
successful  career.  The  richest  departments  in  Honduras  are 
undoubtedly  Tegucigalpa  and  Valle.  Other  departments  in  which 
auriferous  deposits,  vein  or  alluvial,  are  known,  are  El  Paraiso, 
Choluteca,  Gracias,  Comayuga,  Copan,  Santa-Barbara,  and  Yoro.& 

The  following  is  the  estimated  value  of  the  produce  of  gold 
and  gold-ore  in  Honduras  during  recent  years  : — 


Year. 

Value, 
Sterling. 

Year 

Value, 
Sterling. 

1900 
1901 
1902 
1903 

£7,247 
16,491 
14,363 
14,896 

1904 
1905 
1906 

£14,896 

19,495 

7,350 

a  Jalhay,  Bull.  Soc.  Geog.  d'Anvers,  XXVTII,  1904,  p.  39. 

6Leggett,  Trans.  Am.  Inst.  M.E.,  XVII,  1887,  p.  432;    Bourdariart,    Bull.  Soc. 
Beige  de  Geol.,  VII,  1893,  p.  35. 


611 

NICARAGUA. 

The  mineral  resources  of  Nicaragua  are  second  in  importance 
only  to  those  of  Honduras.  Its  placer  deposits  were  worked 
probably  before  the  advent  of  the  Spaniards.  Of  its  mining  history 
during  Spanish  rule  few  records  are  extant,  and  indeed  the  mining 
industry  appears  to  have  been  of  little  importance  during  the 
eighteenth  century.  At  the  time  (1821)  of  the  declaration  of 
Central  American  independence  there  was  not  a  single  producing 
goldmine.  A  revival  of  interest  in  mining  took  place  about  1860, 
but,  of  the  many  mines  then  opened  up,  few  are  now  working. 

The  principal  veins  lie  in  the  central  chain  of  mountains,  and 
particularly  in  the  departments  of  Chontales  (north-east  of  Lake 
Nicaragua)  and  Nueva  Segovia,  on  the  Honduras  frontier.  The 
districts  of  La  Libertad  and  Santo  Domingo,  in  the  latter  depart- 
ment, are  perhaps  the  most  promising.  Their  veins  are  high-grade 
( 1 J  to  2  ounces  per  ton).  The  mining  development  of  Nueva  Segovia 
is  greatly  hindered  by  lack  of  roads,  and  in  most  cases  yields  of  even 
an  ounce  per  ton  are  hardly  profitable.01 

About  1888  rich  placers  were  discovered  on  the  Prinz  Apulca 
and  other  rivers  flowing  north-east  into  the  Caribbean  Sea.  These, 
despite  crude  methods  of  washing,  produced  great  quantities  of 
gold.  In  a  few  years  they  were  exhausted,  and  attention  was 
then  turned  towards  the  gold-quartz  veins  of  the  region.  Many 
of  these  showed  considerable  secondary  surface  enrichment,  raising 
hopes  that  were  dashed  when  the  mines  were  sunk  below  the  zone  of 
oxidation.  There  are,  nevertheless,  several  mines  working  at  a 
profit  on  the  Caribbean  slope.  They  appear  to  be  located  on  veins 
in  andesite.6  The  country  of  the  mining  districts  at  the  head  of 
the  Prinz  Apulca  is  diabase.  The  veins  in  the  diabase  are  of  clear 
quartz  carrying  free  gold,  835  to  871  fine.c 

The  value  of  the  gold  exported  from  Nicaragua  for  the  period 
1902  to  1904  is  :- 


Year. 

Value,  Sterling. 

1902 
1903 
1904 

£96,870 
114,336 
137,303 

a  Jalhay,  Bull.  Soc.  Geog.  d'Anvers,  XXIII,  1899,  p.  323. 

h  Min.  Jour.,  Nov.  16,  1907. 

c  Mierisck,  Petermann  Geog.  Mittheil,  XXXIX,  1893,  p.  35. 


612 


CENTRAL    AMERICA. 


COSTA  RICA. 

This  region  now  known  as  Costa  Rica  was  overrun  by  the 
conquistador  es  somewhat  later  than  was  Mexico  and  Honduras, 
but  by  1514  the  Spaniards  were  firmly  seated  in  power.  Costa 
Rica  (Sp.,  rich  coast)  is  a  portion  of  the  Castille  d'Or,  both 
names  showing  the  estimation  in  which  it  was  held,  and  the  high 
hopes  that  were  entertained  by  the  early  adventurers.  Little  is 
known  of  the  history  of  its  gold  deposits.  The  famous  placer 
deposits  of  the  Monte  del  Aguacate  are  said  to  have  yielded 
£1,400,000  ($7,000,000)  to  the  end  of  1892/*  Most  of  the  mines 
being  worked  in  1907  in  Costa  Rica  were  dependent  on  United 
States  capital.  Two  main  groups  of  mines  occur  near  the  north- 
west coast,  viz.,  the  Bella  Vista  mines  near  Miramar,  15  miles 
from  Puntas  Arenas,  and  the  Abengares  group,  18  miles  from 
Puerto  Yglesias  on  the  Gulf  of  Nicoya.  At  the  latter  place  the 
principal  mines  are  the  Abengares  and  Esperanza.  The  former, 
with  a  40-stamp  battery,  is  crushing  easily-mined  quartz  of  a 
reputed  value  of  15  dwts.  per  ton.  Much  of  the  gold  obtained  in 
Costa  Rica  is  placer-gold,  mainly  derived  from  the  Aguacate 
district,  still  the  most  important  in  this  respect  in  Costa  Rica.  The 
Aguacate  quartz  veins  were  discovered  about  1815  and  are  now  of 
some  importance.6 

The  following  are  the  annual  gold  and  silver  returns  from  Costa 
Rica  in  recent  years  : — 


Year. 

Value,  Sterling. 

Year. 

Value,  Sterling. 

1900 
1901 
1902 
1903 

£32,000 
27,632 
29,482 
46,914 

1904 
1905 
1906 

£8,367 

58,058 

110,645 

PANAMA. 

The  first  gold  obtained  by  Europeans  on  the  mainland  of  the 
Americas  was  that  washed  from  the  river  gravels  of  Panama  in  1502 
during  the  fourth  voyage  of  Columbus  to  the  west.  Since  that  time 
the  sands  of  Darien  have  been  more  or  less  continuously  worked 
by  Spanish  or  by  native  industry. 

The  best-known  gold-quartz  mine  of  the  Panama  regions 
and,  indeed,  the  only  one  of  importance,  is  the  deservedly-famous 


a  Calvo,  "  Republic  of  Costa  Rica,"  Washington,  1894,  p.  19. 
b  Crespi,  Min.  World,  Chicago,  Nov.  9,  1907. 


PANAMA.  613 

mine  of  Espritu  Santo  in  the  Isthmus  of  Darien.  It  is  situated  on 
the  plateau  of  Cana,  about  2,000  feet  above  sea-level  and  at  the 
head-waters  of  the  Tuyra  river  on  the  Pacific  slope  of  the  ranges. 
The  placer  deposits  of  Cana  were  first  worked  about  1665,  and  the 
gold-quartz  vein  of  Espritu  Santo  about  1680."  The  mines  were 
captured  and  the  village  sacked  by  English  pirates  in  1702.  The 
village  was  held  by  the  invaders  for  some  time,  but  they  were  eventu- 
ally forced  to  retreat ;  work  was  at  once  resumed  by  the  Spaniards 
and  was  carried  on  with  great  success.  In  the  beginning  of  the 
eighteenth  century  Espritu  Santo  was  undoubtedly  the  richest  known 
gold  mine.  About  200  miners  were  employed  underground  day  and 
night.  The  ore  was  passed  from  hand  to  hand  along  the  working 
until  it  reached  the  bottom  of  the  shaft,  when  it  was  hauled  to  the 
surface  by  a  windlass.  At  the  surface  the  ore  was  taken  to  the 
river  to  be  crushed  and  washed.  The  miners  were  nearly  all  free 
negroes  who  received,  as  wages  at  the  end  of  the  week,  a  small  dish 
of  crushed  gold-quartz  for  each  day  that  they  had  worked.  As  in 
modern  rich  "pocket"  mines,  a  considerable  amount  of  gold-quartz 
was  stolen.  In  1727  a  great  cave  took  place  in  the  mine,  and  this, 
coupled  with  a  succession  of  determined  attacks  on  the  camp  by 
the  Cana  Indians,  led  to  the  abandonment  of  the  mine.  In  course 
of  time  its  very  site  was  forgotten,  and  was  re-discovered  only 
about  25  years  ago  by  Senor  Vincente  Restrepo,  to  whom  most  of 
our  knowledge  of  ancient  mining  in  Columbia  is  due.  Work  on 
the  old  mine  was  resumed  about  1884.  After  some  desultory  and 
futile  work  by  the  Darien  Gold  Mining  Company,  the  old  Spanish 
workings  were  drained  in  1893  by  an  adit  level  and  rich  ore  was 
at  once  obtained. b 

The  country  of  the  vein  is  an  andesite,  which  is  ordinarily 
greatly  propylitised.  The  greater  part  of  the  ore-body  is  composed 
of  boulders  and  fragments  from  the  adjacent  walls,  some  of  the 
masses  being  many  tons  in  weight.  The  rock  fragments  are  generally 
completely  surrounded  by  concentric  shells  of  sulphides  and  calcite. 
The  order  of  deposition  has  apparently  been  pyrite,  blende,  and 
galena,  with  an  outermost  layer  of  calcite  in  which  acicular  quartz- 
crystals  occur.  The  gold  occurs  for  the  most  part  crystalline, 
but  is  often  met  with  as  wires  or  strings.  As  a  rule,  the  greater 
the  percentage  of  blende  and  galena  present  the  richer  is  the  ore. 
The  prevailing  matrix  is  quartz  and  calcite.  The  gold  is  of  a  very 
much  higher  grade — from  932  to  940  fine — than  would  be  expected 
from  its  occurrence  in  a  Tertiary  andesite.     Of  late  years  the  ore 

a  Kestrepo,  "Gold  and  Silver  Mines  of  Colombia,"  New  York,  1884,  p.  160. 
6  Woakes,  Trans.  Am.  Inst.  M.E.,  XXIX,  1899,  pp.  249,  ct  seq. 


614 


CENTRAL    AMERICA. 


is  becoming  poor  in  depth,  and  the  returns  of  gold  from  this  mine  have 
diminished  so  far  that  prospecting  work  is  being  carried  on  in 
neighbouring  veins  rather  than  on  the  main  Espritu  Santo  lode. 

Elsewhere  in  Panama,  several  futile  attempts  have  been  made 
to  mine  the  erratic  gold-quartz  veins  in  the  decomposed  andesites 
of  the  province  of  Veraguas.      The  Remance  mines  lying  about 


Scale  100  feet=l  inch 

Fig.  208.     Section  of  the  Esprittt  SaKto  Mine,  Cana  (Woakes). 


100  miles  south-west  of  Panama  and  near  Santiago  in  this  province, 
have  been  working  unsuccessfully  for  20  years  on  a  hard  quartz 
vein  6  feet  wide  and  of  a  tenor  of  about  29s.  per  ton.  The  centre 
of  mining  activity  in  Veraguas  is  Canazas.  In  its  neighbourhood 
several  small  veins  have  been  worked  in  augite-andesites  and 
dacites.  At  Viriguas,  30  miles  north  of  Canazas,  are  the  remains  of 
extensive  reservoirs  and  sluices  constructed  at  least  a  century  ago 
to  wash  a  residual  clay  (saprolite)  containing  a  little  gold." 


a  Turner,  Scott,  Min.  Sci.  Press,  1908,  p.  130  ;  Hershey,  lb.,  p.  226. 


Plate  XXXV. 


Cana,  Isthmus  of  Darien.     (Woakes) 


The  Porce  Valley.  Axtioquia,  Colombia. 


PANAMA.  615 

No  placer  mining  of  any  importance  is  now  carried  on  in  the 
Panama  State.  In  1903  gold  to  the  amount  and  value  of  40,570 
ounces  and  £160,189  respectively  was  exported  from  Panama. 


CUBA. 

It  would  appear  that  the  alluvial  auriferous  deposits  of  Cuba 
became  known  to  the  Spaniards  very  soon  after  the  discovery  of 
the  New  World.  As  early  as  1512  a  proportion  of  the  gold  sent 
from  Puerto  Rico  to  Spain  is  recorded  as  having  been  obtained  in 
Cuba.  In  1514,  Diego  Velasquez  wrote  to  the  effect  that  he  had 
completed  an  examination  of  the  Cuban  gold-gravels.  Even  then, 
negroes  were  being  imported  from  Africa  to  work  in  them.  From 
1515  to  1534  gold  to  the  value  of  260,000  pesos  (say  £62,000)  was 
shipped  from  Cuba  to  Spain.  The  royalty  due  to  the  Spanish  crown 
was  10  per  cent,  of  the  amount  collected  by  Spaniards  and  negroes, 
and  20  per  cent,  of  that  obtained  by  Indians.  In  1521  the  latter 
royalty  was  also  fixed  at  10  per  cent. 

The  gold  occurrences  of  Cuba  have  been  minutely  described 
by  Castro  (1868),  special  attention  having  been  paid  to  the  veins 
of  the  Guaracabulla  district,  in  Santa  Clara  province,  in  the  middle 
of  the  island.  Castro  made  numerous  assays  of  the  vein-matrix 
in  the  neighbourhood  of  Holguin,  obtaining  an  average  return  of 
£17  per  ton.  Later  information  has,  however,  showed  that  the 
true  value  of  the  ore,  when,  indeed,  ore  is  available,  is  only  from 
50s.  to  70s.  per  ton.  The  Holguin  veins  are  apparently  thin  clay 
seams  in  serpentine.  Alluvial  gold  has  been  found  near  Puerto 
Principe,  in  the  province  of  that  name.  It  is  also  reported  to  occur 
in  the  vicinity  of  Mantua,  Pinar  del  Rio  province,  on  the  west 
of  the  island. a 

HAITI  (Santo  Domingo  or  Hispaniola). 

On  the  arrival  of  Columbus  from  Cuba,  December  6th,  1493, 
the  caciques  of  Haiti  were  found  to  be  in  possession  of  considerable 
quantities  of  gold  and  golden  ornaments,  derived  from  the  streams 
of  the  interior.  Two  years  later  Pablo  Belvis  arrived  from  Spain 
with  a  great  quantity  of  mercury,  and  initiated  the  search 
for  gold  in  the  New  World  that  was  destined  to  be  fraught 
with  consequences  so  terrible  to  the  unfortunate  inhabitants, 
not  only  of  the  West  Indies,  but  also  of  Central  and  Southern 
America.  The  first  gold  recovered  was  at  once  sent  to 
the    King    of    Spain,    and    was    by    him     forwarded     to     Pope 

a  Hayes,  Vaughan,  and  Spencer,  "Report  on  a  Geological  Reconnaissance  of  Cuba,?' 
Washington,  1901. 


616  WEST    INDIES. 

Alexander  VI.  in  Rome,  where  it  was  dedicated  to  the  service 
of  religion  in  the  gilding  of  a  cathedral  dome !  The  old 
Spanish  historians  are  agreed  that  the  early  yield  of  gold  from 
Haiti  was  enormous.  It  is  said  that,  as  early  as  1502,  240,000  gold 
crowns  (£96,000  or  $468,000)  were  minted  at  La  Vega,  and  that 
most  of  this  gold  came  from  the  Cordillera  de  Cibao.  The  mines 
of  La  Vega  and  the  Cibao  were  visited  by  Bartholomew  Columbus 
in  May,  1496,  and  very  soon  after  the  San  Cristobel  mines  were 
discovered.  The  largest  nugget  recorded  was  that  sent  by  Bobadilla 
to  Spain  in  1502.  It  was  said  to  weigh  about  600  ounces,  but  was 
lost  by  shipwreck  on  the  voyage  across  the  Atlantic.  According 
to  the  Spanish  historian  Herrera,  writing  about  1601,  the  gold  mines 
of  La  Espariola,  in  their  earlier  years  produced  some  £92,000 
( $460,000)  per  annum  !  This  is  probably  an  exaggeration,  and  it  is 
at  least  certain  that  the  gold  yield  of  Haiti  during  the  seventeenth 
and  eighteenth  centuries  was  insignificant. 

The  central  core  of  the  northern  mountains,  the  Cordillera  de 
Cibao,  is  a  post-Cretaceous  hornblende-granite  that  is  intrusive 
through  Cretaceous  limestones  and  shales.  Associated  with  the 
granites  are  diorite  and  dioritic  porphyry. a  The  last  are  the 
metalliferous  rocks  of  the  country,  gold-quartz  veins  and  stringers 
occurring  in  them.  These  veins  have  furnished  the  alluvial  gold 
of  the  streams.  When  the  latter  flow  entirely  through  granite 
areas,  their  sands  are  devoid  of  gold.  The  gold-dust  is  of  high 
quality,  ranging  from  940  to  970  in  fineness.  The  principal  auriferous 
streams  are  the  Jaina  and  Yaqui  on  the  northern  slope  of  the 
Cordillera  de  Cibao.  All  the  tributary  streams  of  the  Yaqui  carry 
gold. 

In  the  south  of  the  island  the  Gosseline  river,  flowing  into  the 
sea  at  Jacmel,  is  auriferous  below  its  junction  with  the  Mabial. 
The  doleritic  basalt  through  which  the  Gosseline  flows,  contains 
•  0003  per  cent.  (2  dwts.  per  ton)  gold.&  No  free  gold  was  visible 
in  the  basalt,  though  flakes  half  an  inch  in  diameter  have  been  found 
in  the  Gosseline  sands. 

Puerto  Rico. — The  placer  gold  of  Puerto  Rico  was  first  worked 
by  the  famous  Ponce  de  Leon  in  1508  a.d.,  using  native  labour  and 
native  methods,  and  the  first  gold  from  this  island  reached  Spain 
in  August,  1509.  For  many  years  the  placers  yielded  considerable 
quantities  of  gold,  and  the  outcrops  of  gold-quartz  veins  were  also 
worked.     By  1535,  however,  the  yield  had  appreciably  diminished, 

a  Roth  well,  Trans.  Am.  Inst.  M.E.,  X,  1882,    p.  345 ;      Garrison,  Eng.  Min.  Jour., 
Juno  15,  1905,  p.  1128  ;  Id.,  ib..  Sept.  14,  1907,  p.  491. 

b  Tippenhauer,  Petermann  Mittheil.,  XLVII,  1901,  p.  169. 


PUERTO    RICO.  617 

and  the  industry  may  be  said  to  have  ceased  some  3  or  4  years 
later.  The  streams  worked  by  the  Spaniards  were  the  Cibuco 
and  the  Maunabo,  the  latter  stream  flowing  to  the  south-east  corner 
of  the  island.  The  total  gold  production  of  Puerto  Rico  is  estimated 
by  McKinley  at  2,294,054  pesos  (£1,222,730  or  $5,964,541). a 

Gold  has  been  washed  in  small  quantities  from  many  streams, 
and  especially  from  the  Luquillo  and  Loiza,  in  the  north  and  east 
of  the  island  of  Puerto  Rico  ;  and  from  the  streams  of  the  Corozal 
district,  25  miles  south-west  of  San  Juan,  in  the  north  of  the  middle 
portion  of  Puerto  Rico.^  From  El  Yunque,  the  highest  mountain 
on  the  island,  and  situated  to  the  north-east,  several  auriferous 
streams  descend.  The  Mameyes,  with  its  numerous  tributaries, 
is  the  richest.  A  considerable  amount  of  washing  was  done  in 
1868  on  the  Anon,  one  of  these  tributaries.  The  rocks  commonly 
found  in  the  watershed  of  the  Mameyes  are  eurite  and  porphyry/ 

In  the  Corozal  district  no  great  quantity  of  gold  has  been  found, 
but  gold-washing  gives  employment  to  a  number  of  peons,  who 
are  believed  to  earn  from  2s.  to  4s.  ($0.50  to  $1.00)  per  diem. 
Hydraulicing  plant  has  been  installed  by  an  American,  who  proposes 
to  divert  a  portion  of  the  Mabille  river.  No  placer  mining  is  at  the 
present  time  carried  on  elsewhere  in  the  island.  There  are,  however, 
evidences  of  former  washings  at  San  German,  10  miles  south-east 
of  Mayaguez,  on  the  west  side  of  the  island.  The  valleys  of  the 
Negros,  Congos,  Cibuco,  Mavilla,  and  Manati  rivers  are  all  known 
to  contain  auriferous  sands.  Near  the  source  of  the  Congos  river 
pieces  of  quartz  have  been  found  containing  120  to  150  grains 
gold.  Nuggets  and  coarse  gold  are  not  uncommon,  the  largest 
reported  from  the  Corozal  river  weighing  more  than  10  ounces. 
The  natives  use  the  wooden  batea,  here  termed  "  gaveta." 

The  central  mountains  of  Puerto  Rico  are  composed  of  water- 
sorted  volcanic  ejecta — tuffs  and  agglomerates — together  with 
dykes  of  hard  black  igneous  rock  containing  white  porphyritic 
crystals.  Sub-crystalline  bluish  limestones  occur  with  the  igneous 
rocks.  In  the  east,  the  underlying  rock  appears  to  be  granite  and 
syenite.  It  is  considered  that  the  original  source  of  the  gold  is  not 
gold-quartz  but  auriferous  pyrite  scattered  through  the  igneous  rocks 
of  the  island.^ 

Up  to  the  present  the  experience  gained  by  prospectors  tends 
to  show  that  the  placer  deposits  of  Puerto  Rico  are  neither  rich  nor 
extensive.  The  annual  yield  of  gold  is  estimated  at  nearly 
400  ounces,  worth  perhaps  £1,200  to  £1,600  ($6,000  to   $8,000). 

a  Min.  Sci.  Press,  July  25,  1908,  p.  129. 

b  Day,  Eng.  Mag.,  XVII,  1899,  p.  242. 

c  Rep.  Dep.  Commerce  and  Labour,  Washington,  1907. 

d  Hill,  20th  Ann.  Rep.  U.S.  Geol.  Surv.,  1900,  Pt.  VI,  p.  794. 


618  WEST    INDIES. 

JAMAICA. 

The  occurrence  of  gold,  with  oxidised  copper  ores  is  reported 
by  Sawkins61  from  the  Charing  Cross  and  Stamford  Hill  mines  in 
the  parish  of  Clarendon.  Selected  fragments  assayed  at  the  rate 
of  15  ounces  per  ton.  A  tradition  is  still  extant  that  the  Spaniards 
worked  for  gold  at  these  mines,  and  Herrera,  writing  about  1601, 
mentions  Jamaica,  together  with  Cuba,  Haiti,  and  Puerto  Rico,  as 
containing  gold. 

TRINIDAD. 

The  southern  slopes  of  the  north-coast  mountains  of  Trinidad 
have  from  time  to  time  furnished  small  gold-specimens.  These 
have  been  obtained  from  Caura,  St.  Ann's,  and  Arima.  The  possibly 
auriferous  belt  is  considered  by  Guppy  b  to  extend  from  the  valley 
of  the  Caura  eastward  along  the  low  hills  at  the  foot  of  the  main 
range.  These  rocks  of  the  northern  range  of  Trinidad  form  part 
of  the  same  massif  that  is  found  in  Tobago  and  in  the  Parian  range 
in  Venezuela.  They  are  limestones,  graphitic  schists,  mica-schist, 
talc-mica-schist,  and  quartzose  grits.  Basic  intrusive  rocks 
(epidiorite)  are  also  found.  While  shoadings  of  quartz  and  quartz 
veins  have  furnished  gold  on  assay,  no  workable  veins  have  as  yet 
been   found.0 


DUTCH  WEST  INDIES. 

Aruba. — In  the  island  of  Aruba,  lying  at  the  mouth  of 
the  Gulf  of  Maracaibo,  42  miles  from  Curacoa,  gold-quartz  veins 
occur  in  syenitic  granite  and  schistose  rocks  that  are  traversed 
by  diorite  and  diabase  dykes  forming  the  heights  and  the  isolated 
plateaux  of  the  island.  The  occurrences  are  therefore  in  all 
probability  to  be  grouped  with  those  of  the  Guianas,  to  be 
described  later. 

Mining  for  gold  in  Aruba  was  commenced  by  the  Spaniards 
who  worked  the  shallow  but  rich  placer  deposits  of  the  "  roois," 
or  normally  dry  thalwegs  that  run  with  water  only  during  the 
rains  of  the  wet  season.  Numerous  outcrops  of  gold-quartz  are 
known  and  have  been  worked  from  time  to  time.  A  stamp  mill 
was  erected  in  1872,  and  to  the  end  of  1874  had  crushed  252  tons 
ore  for  556  "6  ounces  gold  worth  £1,667.  Another  company  working 
from  1878  to  1880  obtained  2,075  ounces  gold  from  2,938  tons  ore.d 

a  Geology  of  Jamaica,  London,  1869,  pp.  34,  189. 

b  Proc.  Vict.  Inst.  Trinidad,  1902,  p.  522. 

c  Cunningham-Craig,  Council  Paper,  Trinidad,  No.  76,  1907. 

d  Rickard,  T.,  "  Aruba  Co.  Report,"  1885. 


DUTCH    WEST    INDIES. 


619 


An  English  company,  holding  a  concession  from  the  Dutch 
Colonial  Office,  carried  on  extensive  mining  operations  for  some 
years,  sinking  to  a  depth  of  600  feet,  but  finally,  owing  to  failure 
to  find  and  open  up  new  ore-bodies,  abandoned  the  concession 
towards  the  end  of  1907.     The  recent  gold  yields  have  been  : — 


Year. 

Kg.  Gold. 

Ounces,  Gold. 

Value,  Sterling. 

1901 

16 

514 

£2,129 

1902 

20 

643 

2,734 

1903 

21 

675 

1,904 

1904 

98 

3,151 

11,110 

1905 

123 

3,954 

16,768 

1906 

72 

2,315 

9,639 

1907 

27,134 

SOUTH   AMERICA. 

The  goldfields  of  South  America  are  disposed  in  three  somewhat 
sharply-separated  areas.  The  chief  is  that  extending  the  length  of 
the  Andes  from  the  Isthmus  of  Panama  to  Central  Chile.  In  its 
northern  portion  and  certainly  as  far  south  as  Valdivia  in  Chile, 
auriferous  impregnation  must  be  attributed  to  Tertiary  igneous 
activity,  manifested  largely  by  the  extrusion  of  andesitic  and 
kindred  rocks.  An  analogy  with  the  auriferous  Calif ornian  Sierra 
Nevada  granodioritic  belt  may  also  be  made  out  in  Chile,  but  in  the 
absence  of  data  concerning  the  general  geology  of  the  Andes,  no 
great  accuracy  in  comparison  is  possible.  Further  south,  in  southern 
Chile  and  in  Tierra  del  Fuego  there  are,  however,  grounds  for  the 
belief  that  the  minor  primary  gold  occurrences  of  those  regions 
are  of  much  earlier  origin,  occurring,  as  they  do,  mainly  in  ancient 
metamorphic  rocks.  The  general  geological  relations  of  the  northern 
and  southern  occurrences,  however,  suggest  here,  as  in  certain 
other  regions  of  Tertiary  auriferous  impregnation,  that  the  gold 
content  of  the  later  effusives  may  have  been  derived  from  deposits 
in  underlying  metamorphic  rocks  that  have  yielded  up  their  gold 
either  by  absorption  of  the  whole  in  an  upward-moving  magma, 
or,  more  probably,  by  the  leaching  action  of  solutions  either 
contained  in  and  attendant  on  the  magma  or  merely  set  in 
circulation  by  it. 

The  second  group  is  contained  in  a  well-marked  petrological 
province  extending  for  650  miles  across  the  hinterland  of  the 
Guianas  from  the  El  Callao  mine  in  the  Yaruari  basin,  Venezuela, 
to  Carsavene  in  the  disputed  Franco-Brazilian  territory.  The 
country   is   essentially  one    of   metamorphic    schists    and   ancient 


620  SOUTH   AMERICA. 

plutonic  rocks  seamed  with  dykes  of  diabase  and  diorite.  Every- 
where the  deposition  of  gold  (primarily  as  auriferous  pyrite)  is 
clearly  to  be  associated  with  the  intrusion  of  the  basic  dykes.  The 
gold  production  of  the  Guianas  is  at  the  present  time  rather  from 
placers  than  from  veins. 

The  third  auriferous  area  of  South  America  is  contained  within 
the  Minas  Geraes  province  of  Brazil.  The  country  of  the  auriferous- 
deposits  is  a  series  of  ancient,  possibly  pre-Cambrian,  not  greatly 
metamorphosed  sedimentaries,  which  lie  on  a  floor  of  granite- 
gneiss  and  schist.  Clear  evidence  of  connection  of  gold  deposition 
with  igneous  intrusions  is  lacking,  and,  indeed,  dyke  rocks  are  not 
anywhere  abundant  in  the  neighbourhood  of  the  gold  mines.  At 
Passagem  and  possibly  also  at  Morro  Velho,  some  faint  relation 
may  be  traced  between  ore-deposition  and  acid  igneous  rocks,, 
but  a  few  diabase  dykes  are  also  known,  and  must  be  considered 
in  this  connection. 

The  isolation  of  the  South  American  auriferous  areas  is  due 
to  the  orogenic  conditions  prevailing  during  the  Tertiary  period, 
conditions  that  permitted  of  the  deposition  of  the  great  masking 
plains  of  the  Orinoco  and  Amazon  and  of  the  rivers  of  the  Argentine. 
It  is  possible  that  with  fuller  knowledge  a  genetic  relation  may  be 
established  for  the  gold-deposits  of  the  Guianas,  Brazil,  and  southern 
Chili,  and  that  the  auriferous  occurrences  of  South  America  may 
thus  be  brought  into  two  groups  instead  of  three. 


COLOMBIAN 

From  those  highlands  of  northern  South  America  now  included 
within  the  boundaries  of  the  Republic  of  Colombia,  came  much 
of  the  treasure  obtained  by  the  Spaniards  after  the  discovery  of 
the  New  World.  Colombia  was  then  the  northern  portion  of  the 
Peruvian  dominions  and  was  inhabited  by  a  harmless  inoffensive 
people  with  a  civilisation  akin  to  that  enjoyed  by  the  more 
southerly  subjects  of  the  Incas.  Possessing  only  the  crudest  of 
weapons  and  unskilled  in  the  use  of  even  these,  the  Indians  offered 
but  a  feeble  resistance  to  the  onslaught  of  the  conquistador es.  Their 
churches  and  their  temples  and,  not  least,  their  graves,  furnished 
abundant  spoil  to  the  ruthless  marauders  whose  sole  purpose — 
the  acquisition  of  the  gold  and  the  treasures  of  the  country — was 

«  Restrepo,  "  Gold  and  Silver  Mines  of  Colombia,"  New  York,  1884,  pp.  1-320  ; 
<  hvcn,  Trans.  Inst.  Min.  Met.,  IV,  1896,  p.  3  ;  Granger  and  Treville,  Trans.  Amer.  Inst- 
M.E.,  XXVIII,  1898,  p.  33;  Nichols  and  Farrington,  Public.  No.  33,  Field  Columbian 
Mus.,  Chicago,  1899  (with  bibliography) ;  Granger,  Eng.  Min.  Jour.,  Aug.  4, 1906,  p.  194  ; 
Petre,  "  The  Republic  of  Colombia,"  London,  1906,  p.  222  ;  Halse,  Trans.  Amer.  Inst. 
M.E.,  XXXVI,  1906,  p.  160. 


COLOMBIA. 


621 


but  thinly  veiled  under  the  cloak  of  Christianity.  It  is  related  of 
Don  Pedro  de  Heredia,  who  set  out  in  1534  in  search  of  the  golden 
•city  of  Mahoa  and  its  ruler,  El  Dorado,  that,  failing  in  his  quest,  he 
remained  in  Colombia,  and  from  the  graves  alone  of  the  Indians 
collected  booty  to  the  value  of  £100,000.  Of  this,  as  indeed  of  other 
treasures  wrung  from  the  unfortunate  inhabitants  of  the  country, 
one-fifth  went  to  the  King  of  Spain  as  royalty.  Even  at  the 
present  day  there  exists  in  Colombia  a  semi-nomadic  class  of  Indians 
(guaqueros)  devoted  to  the  search  for  Indian  graves  (guacas)  of  pre- 
Spanish  times.  One  such  grave  found  in  recent  years  yielded  no 
less  than  300  ounces  gold. 

It  is  probable  that  all,  or  at  least  the  greater  portion,  of  the 
Indian  gold  was  derived  from  placer  deposits  by  simple  batea- 
washing.  After  the  Conquest,  however,  the  Spaniards  by  means 
of  their  unfortunate  slaves,  searched  the  country  systematically 
for  gold.  Spanish  mining,  placer  and  vein,  commenced  about  the 
year  1537.  Both  sources  of  gold  were  so  productive  that 
until  comparatively  recent  years  Colombia  ranked  next  to 
California  and  Victoria  in  the  list  of  the  gold-producing  countries 
of  the  world.  Its  place  is  now  taken  by  the  Transvaal.  Negro 
slaves  were  introduced  at  the  same  period  as  into  Peru  and 
Chile,  and  their  employment  was  continued  until  the  middle  of  the 
nineteenth  century.  In  Antioquia  the  first  vein  mines  were  opened 
up  about  the  end  of  the  sixteenth  century,  and  about  the  same  time 
the  placers  of  the  Pacific-flowing  streams  were  first  worked. 

It  is  difficult  to  estimate  the  past  gold  production  of  Colombia, 
since  the  greater  part  of  it  was  obtained  before  the  days  of  accuracy 
in  statistical  information.  It  has,  however,  been  estimated  by 
Sehor  Vincente  Restrepo,  than  whom  no  one  is  more  competent 
to  judge,  to  the  end  of  1886,  as  follows  : — 


16th  century  (from  1534) 

17th  century 

18th  century 

19th  century  (to  1886) 

(1886-1900) 


20th  century  :— 

Kg. 

1901 

4,215 

1902   . . 

3,796 

1903   . . 

4,100 

1904   . . 

.   2,971 

1905   . . 

3,888 

1906   . . 

3,296 

£41,600,000 
8,216,000 

Sterling. 

£575.216 
517,988 
559,425 
405,421 
530,595 
449,114 


£10,600,000 
34,600,000 
41,000,000 


49,216,000 


3,037,759 


Grand  total  to  end  of  1906 


£138,453,759 


622 


SOUTH   AMERICA. 


The  following  table  compiled  by  Restrepo  shows  the  comparative 
richness  of  the  various  states,  or  rather  departments,  of  Colombia. 
The  yield  is  calculated  to  the  year  1886  : — 


Antioquia 
Cauca    . . 
Tolima  . . 
Santander 
Bolivar . . 
Cundinamarca 
Magdalena 
Boyaca . . 


Panama 


£50.000.000 

49,800,000 

10,800,000 

3,000,000 

14,000,000 

360,000 

200,000 

40,000 

115,600,000 

12,200,000 

£127,800,000 


The  foregoing  estimate  is  probably  rather  under  than  over 
the  truth,  since  evasions  of  the  heavy  Crown  royalty  (20  per  cent.) 
were  common.  Of  the  total  amount,  probably  three-fourths  was 
derived  from  placers  and  the  remainder  from  veins. 

The  chief  auriferous  departments  of  Colombia  are  Cauca, 
Antioquia,  Tolima,  Santander,  and  Bolivar.  Very  little  gold  is 
derived  from  Cundinamarca,  Boyaca,  and  Magdalena.  Until  a  few 
years  ago  Panama  was  a  state  in  the  Colombian  confederacy,  but 
its  autonomy  may  now  be  considered  to  be  secured. 


Antioquia. — In  Antioquia  the  principal  southern  auriferous 
district  is  Manizales,  where  there  are  many  veins  and  numerous 
small  mines.  The  best  known  are  perhaps  those  of  Diamante, 
Gallinazo,  and  Tolda  Fria.  The  elevation  of  the  first-named  above 
sea-level  is  some  12,000  feet.  The  vein-filling  is  a  soft  breccia  of 
trachyte  and  rhyolite/'  The  lode  is  3  to  4  feet  wide  and  is  traversed 
by  small  quartz  veinlets  £  to  1|  inches  wide,  carrying  free  gold, 
auriferous  pyrite,  argentite,  and  a  little  chalcopyrite.  Free  gold 
is  also  disseminated  through  the  brecciated  vein-filling.  With 
increasing  depth  the  tenor  of  the  lode  in  silver  increases  greatly  ; 
at  the  outcrop  it  shows  free  gold  with  only  a  trace  of  silver. 

The  Gallinazo  workings  are  hydraulic,  the  decomposed  surface 
rock  (originally  a  granite)  being  washed  away  to  depths  of  9  to 
60  feet.  The  rock  was  originally  highly  pyritous,  and  it  seems 
probable  that  the  decomposition  of  auriferous  pyrite  has  liberated 
the  gold.  The  average  tenor  of  the  pay-dirt  varies  between  12  and 
25  grains  per  cubic  yard. 

The  Tolda  Fria  mine,  10,000  feet  above  sea-level,  was  opened 
up  in  1873.    Its  vein  is  in  decomposed  talcose  schist,  and  lies  parallel 


a  Nichols  and  Farrington,  loc.  cit.,  p.  156. 


COLOMBIA.  623 

to  the  cleavage  planes.  It  is  only  from  \  to  2  inches  in  thickness — 
perhaps  on  an  average  f-inch — but  is  of  very  high-grade,  reaching 
tenors  of  100  ounces  gold  per  ton.  The  schist  on  either  side  of  the 
lode  is  freely  interlaminated  with  quartz  veinlets,  and  the  whole 
width  of  the  lode-channel  is  estimated  to  carry  from  \\  to  2 
dwts.  gold  per  ton. 

The  El  Zancudo  mine,  4,000  feet  above  sea-level,  and  situated 
near  Titiribi,  south-west  of  Medellin,  was  discovered  about  1793. 
It  was  worked  by  crude  native  Colombian  methods  until  1883, 
in  which  year  it  was  acquired  by  a  foreign  company  with  a  con- 
sequent application  of  modern  knowledge  to  its  exploitation.  The 
main  Zancudo  workings  have  been  in  contact  veins  that  lie  at  the 
junctions  of  metamorphic  schists  (Silurian  ?)  with  overlying 
conglomerate.  In  close  proximity  are  great  bodies  of  diorite. 
From  the  contact-vein  several  droppers  fall  that  eventually  form 
a  strong  lode  in  the  schists.  The  contact-vein  carries  free  gold  and 
silver,  but  the  free  gold  is  replaced  at  depth  by  auriferous  pyrite. 
The  gangue  is  quartz  and  calcite,  while  the  sulphides  are  mispickel, 
chalcopyrite,  blende,  galena,  stibnite,  and  dyscrasite,  together 
with  nickel,  cobalt,  and  manganese  ores.  The  vein  varies  in  width 
from  a  few  inches  to  6  feet.  The  average  tenor  in  gold  is  17  dwts., 
and  in  silver  18  ounces  per  ton. 

The  Buritica  mines  on  the  west  bank  of  the  Cauca,  below 
Antioquia,  are  in  thin  but  exceedingly  rich  veins.  These  mines  are 
famous  throughout  Latin  South  America  on  account  of  the  enterprise 
and  energy  shown  towards  the  end  of  the  sixteenth  century  by 
their  proprietress — Dona  Maria  del  Centeno — who  brought,  at  great 
expense,  water  from  many  miles  distant  to  work  these  mines. 

The  Frontino  mine  lies  in  the  north-west  of  the  Antioquia 
department.  The  country  of  the  mine  is  a  coarsely  crystalline 
diorite.  The  ores  are  auriferous  copper  sulphides  with  pyrrhotite 
disseminated  through  a  quartz  and  calcite  gangue.  Gold-telluride 
of  an  undetermined  species  is  reported  to  be  present.  In  the  oxidised 
zone  cubo-octahedra  of  gold  were  common.  The  average  tenor 
of  the  ore  is  12  dwts.  per  ton.  This  mine  was  originally  owned  by 
the  Frontino  and  Bolivia  Company,  but  in  1877  was  handed  over 
to  the  Antioquia  (Frontino)  Company. 

At  the  Quiuna  mine  the  country  of  the  gold-quartz  vein  is  a 
limestone.  With  the  vein  is  developed  a  chloritic  schistose  rock 
similar  in  character  to  the  metamorphic  andesites  common  in 
some  of  the  Mexican  mining  fields. a 

The  Frontino  and  Bolivia  Company,  working  the  La  Salada 
mines  in  theRemedios  district,  has  for  long  been  the  most  important 

a  Nichols  and  Farrington,  loo.  cit.  sup.,  p.  142. 


624  SOUTH    AMERICA. 

of  the  foreign  gold-mining  companies  operating  in  Colombia.  It 
was  formed  as  far  back  as  1823,  as  the  New  Granada  Company 
and  was  reconstructed  in  1864  under  its  present  title.  The  La 
Salada  mines  are  El  Silencio  and  La  Salada,  both  on  the  same  lode. 
The  former  had  in  1906  attained  a  vertical  depth  of  366  feet.  Until 
1878  they  were  worked  in  the  crude  Colombian  fashion  ;  in  1888 
modern  methods  were  introduced  with  fairly  successful  results. 
The  country  of  the  lode  is  granite,  which  near  the  vein  is  often 
highly  decomposed  and  strongly  impregnated  with  pyrite.  When 
the  last  is  auriferous  the  adjacent  country  is  sent  to  the  mill, 
together  with  the  true  lode-filling. 

Other  gold-quartz  mines,  lying  to  the  north  and  north-east 
of  Remedios,  are  the  Cristales,  San  Nicholas,  Sucre,  and  Cogotes. 
The  country  of  the  Sucre  lode  is  hornblende-granite.  Frequently 
one  wall  of  the  lode,  especially  in  the  neighbourhood  of  the  ore-shoots, 
is  hornblende-diorite-porphyrite.a  The  matrix  is  normally  a  rudely- 
banded  quartz  and,  more  rarely,  calcite.  The  associated  sulphides 
are  pyrite,  marcasite,  blende,  and  galena,  with  occasional  arseno- 
pyrite,  chalcopyrite,  and  pyrrhotite.  The  galena  is  highly  auriferous, 
the  pyrite  much  less  so.  Free  gold  is  also  met  with  even  below 
water-level.  The  fineness  of  the  bullion  recovered  is  609  in  gold 
with  358  of  silver.  The  pay-ore  occurs  in  shoots  that  have  a 
decided  pitch  to  the  east.  Their  length  is  short,  varying  from  100 
to  300  feet,  and  they  are  separated  by  great  stretches  of  barren 
quartz.  They  appear  to  go  to  considerable  depths  and  had, 
indeed,  not  been  bottomed  as  late  as  1906. 

The  Santa  Isabel  mines  are  at  El  Coco,  12  miles  south  of 
Remedios.  They  were  for  50  years  the  property  of  a  Colombian 
family,  but  are  now  worked  by  a  London  company  employing 
electrical  power  and  the  cyanide  process.  Their  country  is  a  dark, 
fine-grained,  very  basic,  hornblendic  gneiss.  Three  veins,  varying 
in  width  from  3  to  5  feet,  are  worked.  These  mines  are  famous  as 
having  produced  from  vughs  in  their  upper  zones  probably  the 
finest  specimens  of  "wire  gold"  extant. 

Cauca. — In  the  Cauca  department,  lying  in  the  west  of 
Colombia,  the  Marmato  is  the  principal  quartz-mining  district. 
Its  history  dates  back  to  1539.  The  mines  lie  about  4,500  feet 
above  sea-level,  or  2,200  feet  above  the  bed  of  the  Cauca,  and  on 
the  mountain  side  to  the  west  of  that  river.  The  country  is  a  hard 
porphyry  (rhyolite).  Several  silver  veins  are  known,  but  the  majority 
of  the  Marmato  quartz  veins  carry  gold  alone  enclosed  in  sulphide- 
ore.     Six  parallel  veins,  varying  in  width  from  2  to  9  feet,    are 


a  Flctt.  quoted  by  Halse,  loc.  cit.  sup.,  p.  160. 


Plate  XXXVI. 


Santa  Isabel  Mine,  Colombia. 


Portovelo  Mine..  Zaruma,  Ecuador.  (Showing  ancient  Spanish  open-cut  in  hill.) 


COLOMBIA.  625 

worked.  The  tenor  is  high,  ranging  from  12  dwts.  to  U  ounces 
gold  per  ton,  but  owing  to  the  refractory  nature  of  the  ore  the  yield 
in  1898  was  only  some  6  to  8  dwts.  per  ton.  A  feature  of  Marmato 
is  its  gold-gardens  (jardin-de-oro)  in  which  the  pyrites  is  collected 
by  the  peons  from  tailings,  and  is  washed  in  the  batea  from  time  to 
time  as  it  becomes  oxidised. 

The  Echandia  mine,  a  few  miles  south  of  Marmato,  is  one  of  the 
most  famous  of  Colombian  mines,  not  so  much  for  its  total  output, 
which  from  1867  to  1898  was  about  £600,000,  as  for  its  extra- 
ordinarily rich  pockets.  The  country  is  hard  blue  porphyry 
(rhyolite),  called  by  the  peons  ojo  de  muerto,  or  "  dead  man's  eye," 
because  of  the  large  size  and  dead  white  colour  of  the  porphyritic 
crystals.  A  dyke  of  diorite  is  intrusive  through  the  acid  rock. 
The  veins  mined  range  in  width  from  1  to  5  feet.  Their  gangue 
is  calcareous.  The  ores  are  pyrite,  galena,  chalcopyrite,  mispickel, 
native  silver,  and  gold.  The  average  value  of  the  ore  is  about 
£6  per  ton,  of  which  silver  represents  10  per  cent. 

The  gold  and  silver  veins  of  Colombia  occur  either  in  the 
andesite  or  more  acid  lavas  (dacites,  trachytes,  &c.)  that  have 
been  erupted  in  later  Tertiary  times,  or  in  the  granites,  or  inter- 
calated in  the  Archaean  schists  (as  at  Tolima)  in  close  proximity 
to  these  lavas  or  to  their  intrusive  representatives.  Owing  probably 
to  the  vigorous  chemical  action  due  to  tropical  influences  a  remark- 
able amount  of  secondary  surface-enrichment  has  taken  place, 
and  has  formed  those  bonanzas  that  helped  so  largely  to  fill  the 
Spanish  galleons  with  their  precious  freight.  In  the  oxidised  zones 
crystallized  gold  is  common.  Cubo-octahedra,  trapezohedra,  and 
rhombic  dodecahedra  are  the  predominant  forms.  The  average 
fineness  of  the  vein-gold  of  Colombia  is  only  698,  a  feature  in  itself 
indicative  of  andesitic  association. 

Placer  Deposits. — As  already  stated,  the  greater  part  of 
the  gold  yield  of  Colombia  has  been  de-rived  from  placer  deposits. 
These  still  give  employment  to  great  numbers  of  peons  who  live 
along  the  water-courses,  often  waiting  for  periods  of  drought  to 
enable  them  to  reach  the  submerged  gravels.  All  the  larger  rivers 
passing  through  Antioquia  are  auriferous,  as  also  are,  or  have  been, 
the  majority  of  the  smaller  tributaries.  Of  the  former,  the  principal 
are  the  Magdalena,  Cauca,  Porce,  and  Nechi.  On  the  two  last 
the  principal  placer  centres  in  the  upper  waters  are  Yarumal,  Cam- 
pamento,  and  Anori,  but  these  rivers  are  washed  as  far  down  their 
courses  as  Caceres  and  Zaragoza.  At  Zaragoza  the  placers  were 
discovered  in  1581,  and  are  said  to  have  yielded  in  18  years  no  less 
than  £1,200,000.  The  largest  nugget  recorded  from  Antioquia 
was  found  in  1851  and  weighed  80-]-   ounces.     Hydraulicing  with 

Ql 


626  SOUTH    AMERICA. 

elevators  and  monitors  has  been  successfully  carried  on  at  various 
spots  on  the  Porce  and  Nechi  rivers.  All  attempts  at  dredging 
hitherto  made  have,  however,  ended  in  failure. 

Choco. — Perhaps  the  most  promising  placer-deposits  in 
Colombia  are  those  of  the  Choco  district.  They  lie  in  the  basins 
of  the  Atrato  river,  flowing  north  to  the  Gulf  of  Darien,  and  of 
the  San  Juan  river,  which  flows  south  and  finally  west  to  the 
Pacific  Ocean.  The  district  is  unfortunately  one  of  the  most  pesti- 
lential regions  in  South  America,  and  for  that  reason  its  gold  output 
diminished  rapidly  when  in  1851  slavery  was  abolished  in  Colombia. 
The  placers  of  the  Choco  were  known  to  Vasco  Nunez  de  Balboa  in 
1513,  but  owing  to  the  savage  nature  of  the  inhabitants  of  this  region 
they  remained  unworked  until  1654.  Nevertheless,  for  the  46 
remaining  years  of  the  seventeenth  century  they  produced 
£4,000,000  gold.  In  the  following  century  the  yield  mounted 
to  £10,200,000.  These  rich  fields  were  first  worked  by  the  com- 
pulsory labour  of  the  Indians,  but  owing  to  the  merciful  intervention 
of  the  Spanish  missionaries  the  supply  of  Indian  slave  labour  was  cut 
off  in  1729.  The  Choco  is  a  country  of  heavy  tropical  rains  and  of 
dense  vegetation,  and  the  placers  are  worked  by  the  resident  negroes 
only  so  far  as  is  necessary  to  furnish  a  bare  existence.  The  gravels, 
both  of  the  Choco  and  the  San  Juan,  are  undoubtedly  rich,  but 
the  deadly  climate  and  difficulties  of  transport  have  hitherto 
prevented  their  successful  exploitation  by  modern  methods.  Never- 
theless, several  hydraulic  claims  have  been  worked  near  the  heads 
of  the  rivers  with  promising  results.  On  the  Andagueda,  near  the 
head  of  the  Atrato,  the  average  amount  of  gold  recovered  by 
extensive  sluicing  was  4|  grains  per  cubic  yard,  including  the 
overburden.  The  pay-streak  was,  however,  worth  from  11  to 
3  dwts.  per  cubic  yard.  The  largest  nugget  that  has  been  obtained 
on  the  Choco  weighed  300  ounces.  As  on  the  eastern  slopes  of 
the  Cordilleras  all  attempts  at  dredging  have  hitherto  failed.  Yet 
the  negroes  have  obtained  as  much  as  12  ounces  per  day  on  the 
Cauca  river  in  extraordinarily  prolonged  droughts.  The  Barbacoas 
district,  lying  along  the  Patia  river  in  the  extreme  south-west  of 
Colombia,  carries  rich  placer  deposits,  but  its  climate  is  no  better 
than  that  of  the  Choco.  The  average  fineness  of  the  placer  gold 
of  Colombia  is  834  with  136  silver.  The  fineness  of  the  vein  gold 
is  only  698  with  302  silver. a 

Tolima. — The  Tolima  department  in  the  south  of  Colombia  is 
noted  rather  for  its  silver  than  for  gold.  Placers  of  considerable 
value  occur  at  Ibague  and  also  at  Victoria,  near  Mariquita. 

"  Kestrepo,  loc.  cit.  sup. 


COLOMBIA.  627 

Bolivar. — The  Bolivar  department  is  auriferous  only  in  the 
south-west,  where  the  gold  belt  of  the  Remedios  district  is  continued 
for  a  short  distance  into  Bolivar. 

Santander. — The  comparatively  small  yield  of  the  Santander 
department  has  been  derived  from  mines  in  the  neighbourhood  of 
Pamplona  on  the  Venezuelan  border,  and  from  placers  in  the  vicinity 
of  Bucaramanga  and  Giron.  These  last  were  productive  in  the 
eighteenth  century,  but  have  now  greatly  declined. 


ECUADOR, 

The  gold  deposits  of  Ecuador,  though  situated  in  wild  mountain 
regions  accessible  only  with  difficulty,  were  known  to  the  conquis- 
tadores  within  the  first  half-century  after  the  discovery  of  America. 
The  famous  Zaruma  mines,  discovered,  or  perhaps  only  re-opened, 
by  the  Spaniards  in  1549,  are  still  the  only  known  gold  veins  of 
value  within  the  republic.  They  were  worked  vigorously  by  the 
Spaniards  and  hy  their  successors.  The  industry  flourished  for 
more  than  two  centuries,  and,  indeed,  until  the  oxidised  zone  was 
exhausted.  During  the  earlier  and  middle  decades  of  the  nineteenth 
century  gold-mining  was  almost  non-existent  in  Ecuador.  Suc- 
cessive attempts  have  been  made  in  recent  years  to  mine  the 
sulphide-zones  of  Zaruma  at  depth,  first  by  a  French  company, 
then  (in  187S)  by  an  English  company,  and  finally  in  1897  by  an 
American  company.  The  last  has  been  successful.  Zaruma  lies 
about  50  miles  distant  from  the  coast  in  the  south-west  portion 
of  the  republic,  and  in  a  mineral  region  that  extends  for 
several  miles  north  and  south.  Its  elevation  is  about  3,000  feet 
above  the  sea.  The  oldest  rocks  in  the  neighbourhood  are  gneisses 
and   crystalline    schists,    apparently    overlain    by   slates. a  The 

country  of  the  gold-bearing  veins  is  andesite.&  According  to 
Finlay,  however,  the  rock  is  a  fine-grained  holocrystalline  diorite. 
Three  veins  have  been  worked.  The  "  Portovelo  "  vein  consists 
almost  entirely  of  calcite  and  contains  a  little  pyrite.  The  "  Mina 
Grande  "  vein  is  characterised  by  the  banded  appearance  of  its 
bluish- white  quartz  and  by  the  presence  of  galena  and  blende. 
Both  the  foregoing  veins  are  faulted  by  the  "  Abundancia  "  cross- 
fissure,  which  has  a  downthrow  of  100  feet.  The  fissure  is  now 
filled  with  quartz.  The  average  thickness  of  the  Zaruma  veins 
is  about  3  feet.  The  oxidised  zone  worked  by  the  Spaniards  extended 
to  a  depth  of  100  feet  only.  The  quartzose  ore,  as  a  whole,  carries 
about  10  to  12  per  cent,  of  sulphides — galena,  pyrite,  chalcopyrite, 

a  Finlay,  Trans.  Am.  Inst.  M.E.,  XXX,  1900,  p.  248. 
6  Mercer,  Eng.  Min.  Jour.,  Aug.  15,  1903,  p.  233. 


628 


SOUTH    AMERICA. 


and  blende.  Not  more  than  50  per  cent,  of  the  gold  is  free.  The 
free  gold  is  734  fine.a  The  average  yield  was  15  to  20  dwts.  per  ton 
in  1901.  being  worth  £3  per  ton  over  a  quantity  of  40,000  tons. 
The  produce  is  exported  as  gold  bars  and  as  cyanide  zinc-slimes. 
In  1905  the  value  of  the  bullion  thus  exported  from  Zaruma  was 
£35,500,,  and  in  1906  £49,000. 

All  the  streams  that  flow  from  the  mountains  toward  the 
Pacific  carry  gold  in  small  quantities,  but  placer  gold  is  worked 
only  in  the  Esmeraldas  district,  along  the  Rio  Santiago,  where  the 
gravels  are  some  80  feet  in  thickness.6  Early  washings  gave  values 
of  9d.  per  cubic  yard,  but  the  average  tenor  of  these  gravels  is 
estimated  at  4d.  to  5d.  per  cubic  yard.  This  tenor  apparently  does 
not  admit  of  a  profit,  for  the  Playa  de  Oro,  the  principal  mine  in 
the  Esmeraldas  district,  was  abandoned  in  1906. 

The  gold  yield  of  Ecuador  for  the  years  1901  to  1906  inclusive 
is  reported  as  follows  : — 


Year. 

Fine  Gold. 
Kg. 

Fine  Gold. 
Ounces. 

Value. 

1901 

165 

5,321 

£22,500 

1902 

301 

9,675 

41,000 

1903 

413 

13,288 

56,345 

1904 

200 

6,430 

27,290 

1905 

284 

9,130 

38,706 

1906 

360 

11,574 

49,000 

BOLIVIA. 

The  auriferous  deposits  of  Bolivia  may  be  grouped  into  three 
divisions.  The  first  extends  from  the  Inambari  basin  on  the  western 
frontier  across  to  the  eastern  frontier  of  the  republic  on  the  Upper 
Paraguay.  It  embraces  the  mountainous  section  of  the  provinces 
of  Caupolican,  Munecas,  Larecaja,  Cercado,  Yungas,  Inquisivi, 
and  Loayza  in  the  department  of  La  Paz,  and  thence  stretches 
eastward  through  Cochabamba  and  Santa  Cruz  to  the  Paraguayan 
boundary.  The  second  region  lies  to  the  south  of  Potosi,  and  east 
of  the  great  Atacama  desert  in  Chile.  The  third  and  the  richest 
lies  to  the  north  of  Lake  Titicaca  and  east  of  the  Carabava  district 
of  Peru  and  includes  the  headwaters  of  the  eastward-flowing  Madre 
de  Dios,  Acre,  and  Puru  rivers. c     In  the  first  region  the  principal 

a  Van  Isschot,  Ann.  des  Mines,  Ser.  9,  XX,  1901,  p.  97. 

b  Higgins,  Bol.  Soc.  Nac.  de  Min.  de  Santiago  de  Chile,  Ser.  3,  XI,  1899,  p.  310. 

c  Bollivian  and  Zarco,  "El  Oro  en  Bolivia,"  Monografas  de  la  Industria   Minera, 
La  Paz.,  1898,  I,  pp.  1-248. 


BOLIVIA.  629 

centre  is  the  San  Juan  del  Oro,  which  must  not  be  confounded 
with  the  river  of  the  same  name  in  the  south  of  the  republic.  At 
the  headwaters  of  the  Suches  river,  north-west  of  Lake  Titicaca, 
there  are  extensive  gravels  and  conglomerates  that  have  been 
estimated  to  contain  tenors  of  8  grains  per  cubic  yard. 

The  Tipuani  river  in  the  Larecaja  province  is  the  richest  in 
Bolivia.  It  flows  from  the  flanks  of  Illampu  or  Sorata  (21,500  feet). 
Its  deposits  appear  to  have  been  discovered  about  the  year  1562. 
Nine  years  later  they  were  extraordinarily  productive,  and  mining 
was  continued  most  successfully  until  native  labour  became  very 
scarce.  This  drawback  was  remedied  in  1620  by  the  extensive 
importation  of  African  negro  slaves,  whose  labour  initiated  a  second 
period  of  prosperity  that  lasted  until  1760.  During  the  next  20 
years  the  output  declined  largely  owing  to  political  troubles,  and  in 
1780  work  was  completely  stopped  by  revolutions.  But  even 
immediately  before  1780  gold  had  been  so  abundant  that  in  that 
year  one  of  the  principal  owners  had  a  stock  awaiting  sale  of  no  less 
than  400,000  ounces.  A  company  working  in  the  Tipuani  river 
from  1818  to  1867  is  reported  to  have  obtained  150,766  ounces  gold. 
Sorata  was  the  chief  town  of  the  gold  region,  and  as  such  was 
famous  throughout  the  world  in  the  seventeenth  century. 

The  auriferous  gravels  of  the  Tipuani  are  of  great  depth,  and 
true  bed-rock  is  seldom  reached.  Concentration  of  gold  generally 
occurs  on  "  false-bottoms  "  of  ferruginous  conglomerates,  locally 
known  as  cangalli.  The  pay-streak  lying  on  the  cangalli  varies  in 
thickness  from  1  to  3  feet,  and  may  carry  an  ounce  of  gold  to  the 
dish  (200  to  250  ounces  per  cubic  yard).  The  thickness  of  the 
cangalli  is  unknown,  since  it  is  rarely  penetrated.  The  gold  is  980 
fine  and  occurs  in  flattened,  oval  flakes.     Nuggets  are  rare.a 

Other  placer  deposits  of  value  are  at  Yani,  Tacacoma,  and 
Chuquiaguillo.  The  last  are  near  La  Paz,  and  were  the  only  placers 
being  worked  in  1906.  They  have  yielded  much  coarse  gold  and 
many  nuggets.  The  heaviest  of  the  latter  weighed  703  ounces 
(95  marcos)  and  was  sent  to  Madrid  in  1718.  Other  nuggets  of 
162  ounces  and  133  ounces  respectively  have  been  found  in  recent 
years.  Of  lesser  importance  are  the  auriferous  gravels  of  Choque- 
camata  (75  miles  from  Cochabamba),  Chiquitos,  and  Rio  de  la  Paz, 
near  the  capital. 

Of  gold-quartz  mines,  the  Araca,  in  the  province  of  Loayza, 
is  the  chief.  The  tenor  of  the  quartz  is  low,  ranging  from  3  to 
8  dwts.  per  ton,  but  as  the  lode  is  very  wide  and  the  ore  free-milling, 
immense  profits  have  been  made  in  past  years.  It  is  believed  to 
still  hold  large  reserves  of  low-grade  ore,  but  is  no  longer  worked, 

a  Frochot,  Ann.  des  Mines,  Ser.  9,  XIX,  1901,  p.  159. 


630  SOUTH    AMERICA. 

owing  partly  to  the  low  tenor  of  the  ore  and  partly  to  the  difficulty 
of  transporting  stores  and  machinery  to  the  mines. 

In  the  second  auriferous  area  lying  to  the  south  of  Potosi  the 
only  veins  calling  for  present  mention  are  those  of  Poconota,  a 
mountain  in  the  department  of  North  Chichas.  They  are  small 
ferruginous  quartz  veins  that  carry  sometimes  as  much  as  10  ounces 
gold  per  ton.  These  veins  were  mined  by  the  Spaniards  on  a  very 
large  scale." 

Alluvial  gold  occurs  in  several  of  the  rivers  of  southern  Bolivia. 
A  recent  attempt  on  an  extensive  scale  to  dredge  the  gravels  of  the 
Rio  San  Juan  do  Oro  near  Tupiza  resulted  in  failure.  Three  dredges 
had  been  erected.  One  of  these  was  dismantled  and  was  being 
re-constructed  in  1908  on  the  Quebrada  de  Esmorca,  a  neigh- 
bouring tributary  of  the  San  Juan. 

The  northern  regions  of  Bolivia,  east  of  Carabaya,  are  little 
known  and  are  inhabited  mainly  by  wild  Indians. 

Soetbeer  estimated  the  yield  of  the  Bolivian  mines  from  1540 
to  1750  at  £420,000,000,  and  from  1750  to  1870  at  £250,000,000. 
These  estimates  are  certainly  far  too  high,  and  the  estimate  quoted 
byFrochot6  for  the  period  1545  to  1875,  viz.,  £41,013,000,  is 
probably  much  nearer  the  truth.  From  1895  to  1899  an  average 
of  505  kg.  gold  worth  about  £65,000  was  annually  produced.  Since 
then  the  yield  has  diminished  considerably,  the  average  for  the 
three  years,  1903  to  1905,  being  only  about  £4,583  ($21,995).c 

/4v> — u 


PERU. 

Peru  may  be  divided  from  west  to  east  into  three  lateral  belts — 
the  Coast,  Sierra,  and  Montana  zones — the  physiographical  character 
of  each  being  sufficiently  indicated  by  its  designation.  Gold  occurs 
in  all  three  belts,  but  its  method  of  occurrence  is  different  in  each. 
In  the  Coast  region  it  is  found  in  thin  veins  in  granites.  The  gangue 
is,  in  the  oxidised  zones,  quartz  with  ferruginous  oxides  ;  in  depth 
the  gold  is  partly  free  and  partly  associated  with  pyrites.  The 
principal  veins  of  this  region  are  those  of  Andaray,  Montes  Claros, 
and  Otaca.^ 

The  Sierra  region  contains  numerous  veins  of  auriferous  quartz, 
whilst  most  copper-pyrites  veins  also  carry  a  little  gold.  The 
departments  of  Ancachs,  Apurimac,  and  Cerro  de  Pasco  are  the 
most  noteworthy.     In  the  Cerro  de  Pasco  district,  famous  for  its 

a  "Bolivia,"  Bureau  S.  Amer.  Republics,  Washington,  1904,  p.  119. 

"  Loc.  cit.  sup. 

c  Min.  Industry,  1906,  p.  884. 

d  Laroza,  Mining  Mag.,  New  York,  XI,  1905,  p.  50. 


PERU. 


631 


great  silver  mine  of  the  same  name,  is  the  Quinua  mine  of  the 
Chiquitambo  Gold  Mining  Company.  The  country  in  the  neighbour- 
hood of  the  veins  of  Quinua  is  Upper  Cretaceous  dolomite,  limestone, 
red  sandstone,  and  fossiliferous  marl.  Through  the  sedimentary 
rocks  are  intruded  two  andesite  dykes.  The  auriferous  quartz  is 
distributed  in  pockets  in  the  dolomite.  This  mine  was  in  the  early 
part  of  1908  yielding  about  250  ounces  per  month. 


CHUQUITAMBO 
HILL 


Auriferous  quartz 

Dolomite 

Andesite 

Limestone 

Fossiliferous  marls 

Red  sandstone 

Fig.  209.     Section  through  the  Quinua  Mine  (Laroza). 


In  the  Montana  region  the  departments  of  Cuzco  and  Puno 
are  the  most  productive.  In  this  region  gold  occurs  in  the  richer 
areas,  as  in  that  of  Carabaya  (north-west  of  Lake  Titicaca),  in  quartz 
veins  in  Silurian  slates.  The  principal  mine  now  being  worked 
is  the  Santo  Domingo,  owned  by  the  Inca  Gold  Mining  Company 
(Philadelphia).  The  gold  of  its  veins  is  accompanied  by  pyrite  and 
stibnite.  The  mine  is  situated  on  the  eastern  slope  of  the  Andes, 
and  may  be  reached  only  by  a  long  and  arduous  mule  journey. 
It  has  been  highly  productive  for  several  years  and  for  some  time, 
though  crushing  with  only  a  10-stamp  mill,  was  yielding  £25,000 
gold  per  month.     In   1903  its  output  was  15,580  ounces  gold. 

Placer  deposits  are  numerous  in  the  province  of  Sandia  (north 
of  Titicaca  and  south-east  of  Carabaya).  The  tenor  of  the  gravels 
of  Aporona  in  this  province  has  been  estimated  at  lOd.  per  cubic 
vard.    The  sands  of  all  the  rivers  of  the  Eastern  Cordilleras  contain 


632 


SOUTH   AMERICA. 


gold,  some  of  which  is  recovered  by  the  native  method  of  trans- 
forming the  dry  beds  of  the  streams  into  rude  sluices  by  paving 
the  bottom  with  rough  stones,  the  gold  settling  in  the  interstices 
between  the  stones  during  the  floods  of  the  wet  season.  By  this 
method  no  less  than  7,572  ounces  gold  were  obtained  in  1903. 
^Modern  hydraulic  methods  have  been  adopted  in  a  few  cases,  as  at 
the  San  Antonia  de  Poto  mine  (Sandia  district),  which  yielded 
2,666  ounces  gold  during  1903.  The  conglomerate  gravels  of  the 
Poto  are  from  60  to  180  feet  thick.  The  pay-streaks  within  the 
gravels  are  from  6  to  10  feet  thick  and  carry  perhaps  3 \  to4J  grains 
per  cubic  yard  (-3  to  4  gramme  per  cubic  metre)."  Dredging  on  a 
large  scale  was  being  inaugurated  in  1907  on  the  Rio  Inambari  in 
the  Carabaya  province  and  on  the  boundary  between  Peru  and 
Bolivia.  The  extensive  placers  of  Pataz  and  Sandia,  as  well  as 
those  of  the  Rio  Nusimiscato,  were  also  attacked  by  modern 
methods.  In  the  latter  river  the  distribution  of  the  gold  is  very 
irregular,  no  clearly-defined  boundary  existing  between  the  over- 
burden [cargo)  and  the  pay-streak  (venero).  The  tenor  of  these 
gravels  where  examined  varied  from  less  than  \  grain  to  4 \  dwts. 
per  cubic  yard.&  Large  nuggets  have  in  bygone  years  been  found 
in  the  Peruvian  gold-gravels.  One  from  the  Carabaya  district 
weighed  1,503  ounces,  and  was  forwarded  to  Spain  for  presen- 
tation to  Charles  V.  (1517  — 1558). c 

The  following  table  indicates  the  varied  sources  of  the  gold 
of  Peru,  the  year  1906  being  selected  : — 


Kg. 

Gold  in  in 

igots,  dust,  &c. 

..       966-108 

,,      from  lead  bars        .  .          . . 

12-671 

9>                    J> 

pyritous  silver  ores 

16-513 

»>                    >> 

auriferous  mattes 

14-059 

)9                    J  ? 

various  minerals 

.  .       234-265 

?5                     )> 

ingot  copper 

3-730 

1,247-346 
The  gold  yield  of  Peru  during  recent  years  is  as  follows 


Year. 

Fine  Ounces. 

Value,  Sterling. 

1903 
1904 
1905 
1906 

34,667 
19,335 
24,967 
40,091 

£147,262 

82,134 

106,062 

170,355 

a  Malsch,  Verb,  des  Deutsch.  Wissen.  Vereins.  zu  Santiago  de  Chile,  IV,  1899,  p.  339. 

h  Duenas,  Bol.  Cuerp.  Ing.  Min.  de  Peru,  Lima,  LIII,  1907. 

c  For  detailed  accounts  of  the  geology  and  auriferous  occurrences  of  Peru,  see  Boletin 
del  Cuerpo  de  Ingenieros  de  Minas  del  Peru,  Lima,  1902-1908. 


633 


VENEZUELA. 


Gold  is  widely  distributed  throughout  Venezuela,  but  it  is  only 
in  the  Yaruari  district,  in  the  basin  of  the  river  of  that  name,  south 
of  the  Orinoco,  that  it  occurs  in  appreciable  quantity.  Its  existence 
has  been  noted  from  the  west  of  Valencia  in  weathered  gneiss  ; a 
from  near  Carupano,  on  the  same  mountain  chain  as  that  of  northern 
Trinidad  ;b  and  from  metamorphic  schists  in  the  neighbourhood 
of  Caracas.  The  Yaruari  river  flows  southward  to  join  the  Cuyuni, 
the  main  western  tributary  of  the  Essequibo  in  British  Guiana.  The 
possession  of  the  Yaruari  basin  had  long  been  a  subject  of  dispute 
between  Great  Britain  and  Venezuela,  but  the  question  was  settled 
in  1898  by  an  award  in  favour  of  Venezuela.  The  chief  mine  of  the 
district  is  the  famous  El  Callao,  in  its  day  one  of  the  richest  of  the 
world's  gold  mines.  It  was  possibly,  indeed,  a  faint  rumour  of  former 
workings  on  these  mines  that  gave  rise  to  the  El  Dorado  legend 
of  the  early  years  of  the  sixteenth  century.  Between  the  Orinoco 
and  the  Amazon  there  lay  the  dominions  of  the  golden  emperor, 
"  El  Dorado,"  the  last  of  the  Incas.  His  was  the  gorgeous  city 
of  Mafioa  situated  on  the  shores  of  the  beautiful  lake  of  Parima. 
From  1536  to  1746,  and  especially  in  the  earlier  years  of  the  period, 
numerous  expeditions,  commencing  with  that  of  George  de  Spires, 
were  made  in  search  of  Mahoa  by  soldiers  of  fortune  from  all  the 
principal  European  nations.  Of  the  English,  Sir  Walter  Raleigh 
alone  need  be  mentioned.  They  all  failed,  it  is  true,  in  their  quest, 
but  they  nevertheless  rendered  a  lasting  service  to  geographical 
science. 

El  Callao. — Gold  was  discovered,  or  more  probably,  re-dis- 
covered in  the  Yaruari  district  in  1849  by  Dr.  Plassard,  or,  according 
to  other  authorities,  in  1856,  by  Friedrich  Sommer,  but  it  was  not 
until  1865  and  1866  that  the  rich  veins  of  Chile,  Potosi,  and  El 
Callao  were  successively  opened  up. 

The  rocks  of  the  region  are  ancient  metamorphic  schists 
associated  with  a  gneiss  that  is  intruded  by  granite  and  quartz- 
porphyry.  The  schists  are  talcose,  micaceous,  and  amphibolitic.  The 
whole  series  in  Venezuelan  Guiana,  as  indeed  in  the  other  Guianas,  is 
intruded  by  basic  rocks,  mainly  diabase  and  diorite.  In  the  Nueva 
Providencia  district,  which  contains  nearly  all  the  auriferous  occur- 
rences, the  veins  lie  in  the  widely-developed  diabasic  member  of  the 
series.  Though  quartz  veins  are  met  with  in  great  numbers  in  the 
schists,  it  is  only  where  they  are  in  close  connection  with  the  diabase 

°  Wall,  Q.J.G.S.,  XVI,  1860,  p.  463. 
b  Ann.  des  Mines,  I,  1852,  p.  600. 


634 


SOUTH    AMERICA. 


that  they  become  auriferous. a  A  much  later  intrusive  diabase, 
north  of  the  Yaruari  river,  is  associated  with  a  diallage  rock  that  is 
probably  a  gabbro.  The  most  productive  lodes  of  the  Yaruari 
were  the  Callao,  Chile,  Potosi,  and  Caratal.  All  except  the  Callao 
have  a  strike  practically  east  and  west.  El  Callao,  however,  swings 
to  the  north  until  it  runs  north  and  south  across  the  Yaruari  river. 
The  Chile  vein  dips  south  about  55°  and  has  a  thickness  of  some 
4  feet.  At  the  outcrop  its  tenor  was  an  ounce  per  ton,  but  at  200  feet 
in  depth  it  had  risen  to  5  to  6  ounces  per  ton.  On  its  hanging-wall 
and  separated  from  it  by  only  a  few  feet  of  country  is  a  lode,  or, 
more  probably  a  bed,  of  red  hornstone  or  jasperoid  rock  locally 
known  as  porfido  or  piedra  morada.  This  rock  contains  pyrite. 
It  is  found  in  many  places  in  the  district  and  is  everywhere  regarded 
by  prospectors  as  a  favourable  indication  for  gold  veins. 

El  Callao  lode  ran,  as  already  stated,  almost  north  and  south, 
and  dipped  west.  Its  thickness  was  only  from  1  to  2  feet.  The 
quartz  was  white  and  somewhat  vitreous  and  contained  much  coarse 
lamelliform  gold  associated  with  a  little  pyrite.  The  country  of  the 
vein  is  termed  "felstone  "  by  Le  Neve  Foster.6  A  cursory  inspection 
of  specimens  collected  by  him  and  now  in  the  Museum  of  the 
Geological  Society  of  London,  indicates  that  the  felstone  is  either 
a  true  felsite  or  a  highly  silicified  sedimentary  rock,  probably  the 
former, but  in  either  case,  a  member  of  an  ancient  schistose  complex. 
The  felstone   contains  numerous   crystals   of  pyrite. 

In  1895  the  El  Callao  mine  was  no  longer  able  to  pay  expenses, 
and  was  closed  down.  It  had  a  capital  of  £3,220,000,  and  had  during 
its  life  milled  719,257  tons  of  quartz  for  a  yield  of  1,438,638  ounces 
gold.c  Over  one-third  of  the  total  production  was  distributed 
in  dividends  among  the  shareholders. 

East  of  El  Callao  the  Corinna  lode  is  in  decomposed  schist. 
The  Tigre  and  several  other  lodes  to  the  south  lie  in  diabase.  Con- 
siderable secondary  auriferous  deposition,  due  to  the  decomposition 
of  pyrite,  has  taken  place  in  all  these  veins,  in  the  vughs  and  cavities, 
which  are  often  plated  and  are  occasionally  nearly  filled  with 
leafy  gold.  In  nearly  every  case  the  gold  of  the  Caratal  district 
appears  to  have  been  originally  associated  with  pyrite.  In  1907 
only  one  gold-mining  company  was  working  regularly  in  the  Yaruari 
district. 

A  considerable  quantity  of  gold  was  also  obtained  from  the 
placers  of  the  Yaruari  basin,  especially  in  the  quebradas  (valleys) 


a  Attwood  and  Bonney,  Q.J.G.S.,  XXXV,  1879,  p.  582. 

6  Q.J.G.S.,  XXV,  1869,  p.  336. 

c  The  writer  has  been  unable  to  ascertain  whether   the  last   figures  denote  British 
ounces  of  31  •  15  grammes  or  Spanish  onzas  of  28-75  grammes. 


VENEZUELA. 


635 


of  the  Tigre,  Peru,  Aguinaldo,  &c.  In  these  valleys  the  gold  occurs 
both  in  the  ordinary  way  on  "  bottoms,"  on  cascajo  or  decomposed 
bed-rock,  and  also  below  laterites  (moco),  the  latter  being  regarded 
as  indicative  of  good  pay-gravel.  Dredging  was  attempted  on  the 
Yaruari  river  in  1899,  but  proved  a  failure. 

The  gold  yield  from  Venezuela  in  recent  years  has  been  : — 


Year. 

Kg. 

Ounces. 

Value,  Sterling. 

1900 

600 

19.290 

£63,904 

1901 

842 

27,070 

89,151 

1902 

653J 

20,994 

89,076 

1903 

451 

15,000 

61,602 

1904 

262*1 

8,423* 

30,708* 

1905 

621 

19,965 

60,163f 

*  Second  half-year  only. 

f  Includes  £1,428  value  of  gold  ore  exported. 

J  Fine  ounces. 

Several   discrepancies  will  be   noted  in  the    foregoing    table, 
which  is  nevertheless  compiled  from  official  sources. 


BRITISH    GUIANA. 

The  geology  of  British  Guiana  is,  in  its  broader  aspects, 
extremely  simple.  For  50  to  70  miles  from  the  coast  the  country 
is  covered  with  interbedded  clays,  sands,  and  silts  of  recent  or 
Pleistocene  origin.  Further  in  the  interior,  in  the  few  spots  where 
outcrops  of  bed-rock  are  obtainable,  Archaean  metamorphic  rocks, 
varying  in  character  from  aplite-gneiss  to  hornblende-schist,  are 
exposed.  The  foliated  rocks  are  intersected  by  belts  of  granitite 
and  by  masses  of  true  granite.  In  other  parts  the  gneissose  rocks 
give  place  to  wide  areas  of  porphyries,  porphyrites,  and  felsites. 
Overlying  the  Archaean  rocks  in  some  regions  is  a  great  development 
of  unfossiliferous  sandstone  and  conglomerate  of  unknown  age. 
Both  the  Archaean  rocks  and  the  sandstones  are  penetrated  by 
dykes  and  sills  of  diabase.  In  places,  as  at  Koraima,  the  diabase 
appears  to  have  been  developed  as  laccoliths.  Elsewhere  it  has 
flowed  over  the  Archaean  rocks. a  Gold  is  found  widely  diffused  in 
the  districts  occupied  by  the  Archaean  rocks,  but  only  in  payable 
quantities  where  certain  conditions  prevail.  The  chief  of  these 
appears  to  be  the  intrusion  of  basic  igneous  rocks.  The  basic  rocks 
are  of  two  periods  ;   the  earlier  belonging  to  the  gneissose  formation 


a  "  Gold,  &c,  of  British  Guiana,"  Georgetown,  1903,  p.  4. 


636 


SOUTH   AMERICA. 


and  probably  originally  gabbro  and  diabase,  but  now  converted 
to  quartz-diorite,  epidiorite,  amphibolite,  and  hornblende-schist, 
while  the  later  igneous  rock  is  an  unaltered  diabase. 

The  former  type  of  rocks  yields  the  Groete  Creek  goldfield  ; 
parts  of  the  Cuyuni  goldfields  ;  the  Puruni  field  ;  and  that  of  the 
upper  Mazaruni.  Gold  appears  to  be  diffused  through  the  mass  of 
rock  and  to  be  set  free  during  its  weathering  and  degradation. 
Some  of  the  British  Guiana  rocks  contain  sufficient  gold  disseminated 
through  their  bulk  to  account  for  economically  valuable  placers." 

Where  the  Archaean  rocks  are  traversed  by  dykes  of  the  later 
diabase,  gold  is  not  infrequently  found  in  the  decomposition 
products,  especially  in  the  vicinity  of  the  junction  of  gneiss  and 
diabase.  Where  the  diabase  dykes  traverse  a  district  already 
intersected  by  intrusions  of  quartz  porphyry,  felsite,  and  allied 
rocks,  the  junctions  are  frequently  rich  in  gold,  and  from  their 
degradation  products  many  rich  placers  have  been  derived.  The 
auriferous  deposits  occur  most  frequently  where  the  dykes  of 
diabase  are  small  and  numerous. 

A  third  locus  of  gold,  at  times  of  economic  importance,  is  in 
highly  mineralised  acid  rocks,  such  as  the  aplite  of  Omai.  In  many 
places  there  occur  pegmatite  veins  that  gradually  pass  into  quartz 
veins  in  lateral  extension,  but  these  are  almost  always  barren. 

The  fineness  of  the  placer  gold  of  British  Guiana  gold  varies 
from  914  in  the  Potaro  to  932  in  the  Puruni  district.  The  alluvial 
gravels,  except  at  Omai,  where  a  hydraulic  plant  was  erected,  and 
at  various  spots  where  dredging  has  been  attempted,  are  worked 
by  simple  methods  of  sluicing. 

The  alluvial  gold  of  British  Guiana  is  found  in  the  gravels  of 
the  existing  streams.  Ordinarily,  the  pay-streak  is  only  from  2  to 
3  feet  thick,  while  the  overburden  is  from  4  to  7  feet,  but  may 
reach  in  a  few  cases  20  feet  in  thickness.  The  pay-streak  rests 
on  clay  or  on  decomposed  bed-rock.  As  a  rule  the  amount  of  pay- 
gravel  in  the  smaller  streams  is  insignificant.  The  extensive  use 
of  hydraulicing  installations  is  thus  precluded.  Most  of  the  gold- 
washing  is  therefore  done  with  the  "  torn  "  or  sluice  by  small  parties 
of  independent  negro  gold-washers,  locally  termed  "  pork-knockers." 
Gravel  containing  less  than  2  dwts.  per  cubic  yard  cannot  be  worked 
at  a  profit  with  "  toms  "  and  negro  labour.  With  sluices,  however, 
gravels  of  a  somewhat  lower  tenor  (1  to  1^  dwts.  per  cubic  yard) 
may  be  treated. b 


"  Harrison,  Rep.  Inst.  Mines,  Brit.  Guiana,  1906. 
b  Powell,  Trans.  Inst.  Min.  Met.,  VIII,  1900,  p.  354. 


BRITISH    GUIANA.  637 

Only  one  large  hydraulicing  company  has  carried  on  operations 
in  British  Guiana,  viz.,  the  Demerara  Exploration  Company, 
working  at  Omai  on  the  Essequibo  river.  This  company  commenced 
work  in  July,  1902,  but  by  1907  had  exhausted  its  sluicing  ground 
and  had  ceased  operations  in  that  direction.  In  1904,  the  company 
placed  on  Gilt  Creek,  near  Omai,  a  small  dredge  that  had  been 
working  with  indifferent  success  on  the  Barima  river.  Its  operation 
proving  successful,  a  larger  dredge  with  5  cubic  feet  buckets  was 
placed  in  commission  in  June,  1906.  So  far  as  they  are  available 
the  total  returns  of  this  company  from  sluicing  and  dredging  appear 
to  have  been  : — 


July,  1902 

to 

March,  1903 

2,250  crude  ozs 

1903 

1904       . 

4,392  fine  ozs. 

1904 

1905       . 

12,683       „     „ 

1905 

1906       . 

12,651       „     „ 

1906 

1907 

948*     .,     „ 

*  From  the  large  dredge  alone  and  for  eight  months  only. 

Dredging  at  Omai  has  been  largely  hindered  by  buried  logs 
and  trees.  The  fineness  of  the  alluvial  gold  ranges  from  882  to  960. a 

On  the  Conawaruk  river  a  large  dredge  was  erected  and  com- 
menced work  in  January,  1907.  The  costs  of  working  were  estimated 
at  £69  per  week,  and  the  returns  were  at  the  rate  of  £150  per  week. 
To  June  30th,   1907,  it  had  produced  61 2^  ounces  gold. 

Gold-quartz  veins  have  never,  up  to  the  present,  contributed 
materially  to  the  gold  output  of  British  Guiana.  As  early  as  1863, 
however,  a  small  quartz  vein  was  opened  up  at  Wariri,  on  the 
Cuyuni  river,  but  was  abandoned  before  it  had  reached  the  producing 
stage.  In  1892-3  a  remarkable  boom,  based  on  a  single  rich  pocket 
of  vein  quartz,  took  place  in  Demerara.  The  boom  collapsed  as 
soon  as  the  pocket  was  worked  out,  a  matter  of  only  a  few  days 
to  the  20-head  stamp  battery  that  had  been  erected  to  treat  it. 
The  first  serious  gold-quartz  mining  was  at  the  Kaniamapoo  mines, 
some  distance  up  the  Demerara  river,  and  east  of  Omai.  The  quartz 
was  of  very  low  tenor.  The  initial  crushings  yielded  at  the  rate  of  2£ 
dwts.  per  ton  or  480  ounces  in  all.  The  mine  was  soon  abandoned. 
A  Huntington  mill  was  also  in  operation  at  the  Aparpoo  mine, 
5  miles  further  north. 

The  Barima  mine  at  Arakaka  Creek,  in  the  north-west  portion 
of  the  colony,  produced  in  1896-7,  8,017^  ounces  gold  from  9,500 
tons  quartz,  an  average  of  1688  dwts.  per  ton,  before  exhausting 
the  ore-shoot  on  which  it  was  working.    Its  veins  lie  in  a  decomposed 

a  Lungwitz,  Zeit.  fur  prakt.  Geol.,  1900,  p.  213. 


638  SOUTH    AMERICA. 

diabase.  Mining  appears  to  have  been  abandoned  in  subsequent 
years  owing  to  lack  of  ore  developed.  The  mine  was,  however, 
reopened  in  1907.  The  veins  of  the  region  vary  greatly  within 
themselves  in  size  and  in  value.  The  oxidised  zone  reaches  on  an 
average  a  depth  of  100  feet.  At  this  depth  the  ore-bodies  are 
usually  impoverished,  but  the  tenor  of  the  ore  as  a  rule  rises  slightly 
on  passing  into  the  sulphide  zone. 

The  most  promising  mine  in  British  Guiana  in  1908  was 
the  Peters  mine,  situated  on  the  right  bank  of  the  Puruni  river. 
Its  veins  lie  in  solid  hornblende-schist.  Milling  commenced  with 
a  15-stamp  mill  in  September,  1905,  and  by  the  end  of  June,  1906, 
8,278  ounces  gold  had  been  obtained  from  quartz  of  a  tenor  of  15 
dwts.  per  ton.  In  1906-7  a  further  9,500  ounces  were  recovered 
from  12,621  tons  ore.  Its  workings  had  in  1908  reached  a  depth  of 
300  feet. 

An  interesting  occurrence  is  that  of  Omai,  Essequibo  river. 
The  surface  rock  here  is  a  diabase  which  is  associated  with  aplite 
and  granitite.  At  a  depth  of  964  feet  borings  through  the  acid 
rocks  came  upon  epidiorite.  The  Archaean  rocks  of  the  country 
are  apparently  intruded  by  this  mass  or  stock  of  aplitic  granite. 
After  its  intrusion  there  was  a  succession  of  outbursts  of  diabase, 
and  the  latter  rock  is  now  developed  both  above  and  below  the 
aplite.  The  interest  of  the  occurrence  lies  in  the  fact  that  the  aplite 
is  auriferous,  selected  specimens  assaying  as  high  as  15  dwts.  per 
ton.  The  aplite  further  carries  in  depth  a  great  deal  of  pyrites, 
and  the  gold  found  is  probably  to  be  associated  with  that  mineral. 
Small  quartz  veins,  which  are  exceedingly  numerous  in  the  aplite, 
are  slightly  auriferous. a  During  1904-5,  ninety  per  cent,  of  the 
total  yield  of  the  company,  or  more  than  22,600  ounces  gold,  was 
obtained  by  sluicing  the  highly  decomposed  aplite.  It  was  worked 
out  in  benches  to  150  feet,  to  which  depth  the  aplite  was  freely 
decomposed.  The  gold  was  free  and  often  well  crystallized,  and 
there  was  no  pyritous  residue  in  the  wash.  The  acidic  rock  is 
therefore  the  primary  source  of  much  of  the  alluvial  gold  of 
Omai.6  The  only  occurrences  readily  comparable  with  that  of 
Omai  are  those  of  Berezovsk,  in  the  Urals,  and  of  Gallinazo, 
Colombia. 

In  1907  about  80  per  cent,  of  the  gold  yield  of  British  Guiana 
was  produced  by  individual  miners  and  small  parties.  From  1884 
to  the  end  (June  30th)  of  the  fiscal  year  1899-1900  the  total  output 

11  Lungwitz,  Zeit.  fur  prakt.  Geol.,  1900,  p.  213  ;   Harrison,  Govt.  Reports,  George- 
town, 1900,  p.  10  ;  Id.,  ib.,  1905,  p.  52. 

"  Linck,  in  verb. 


Plate  XXXVII. 


Decomposed  Aplite  Dyke,  sluiced  for  Gold. 


General  View 

The  open-cut  made  by  sluicing  away  the  aplite  may  be  seen  traversing  the 
ridge  in  the  middle  background. 

OMAI,  BRITISH  GUIANA. 


BRITISH    GUIANA. 


639 


of  the  colony  had  been  1,250,469  crude  ounces, 
year  there  have   been   produced  : — 


Since  the  latter 


Year. 

Crude  Ounces. 

Value,  Sterling 

1900-1 

114,102 

£409,968 

1901-2 

101,332 

369,450 

1902-3 

104,527 

381,080 

1903-4 

90,336 

329,350 

1904-5 

95,864 

349,504 

1905-6 

94,363 

334,202 

1906-7 

85,505 

303,542* 

*  Estimated. 


DUTCH  GUIANA  (Surinam). 

Gold  in  Surinam  is  entirely  derived  from  placer-mining  of 
comparatively  recent  development,  for  though  it  had  long  been 
known  that  gold  occurred  in  the  hinterland,  it  was  only  after  the 
sugar-cane  industry  had  ceased  to  be  profitable  that  attention  was 
turned  towards  the  minerals  of  the  country.  The  first  gold-deposits 
of  consequence  were  found  in  1885-6  on  the  Lawa  river,  a  tributary 
of  the  Marowyn,  which  separates  Dutch  from  French  Guiana.  These 
proved  very  rich  for  a  time,  and  led  to  the  establishment  of 
permanent  workings  on  both  the  Dutch  and  French  sides  of  the 
river.  Speaking  generally,  the  placer  deposits  of  Dutch  Guiana 
lie  in  the  east  and  south-east  of  the  colony.  The  "  bottom  "  of 
the  placers  is  almost  everywhere  a  stiff  clay.  The  gravel  is  treated 
in  "  long-toms  "  or  in  sluice  boxes.  The  gold  is  often  coarse,  and 
nuggets  are  not  rare.  Of  the  latter  the  heaviest  recorded  weighed 
530  ounces  (16-5  kilos). a  The  gravels  are  often  highly  ferruginous, 
in  which  case  the  gold  is  often  coated  with  iron  oxides,  necessitating 
considerable  care  in  the  treatment  by  amalgamation  of  the  con- 
centrates obtained  by  washing.  The  large  nugget  above-mentioned 
was  thus  coated,  and  nearly  escaped  observation.  Labour  is  scarce, 
ineffective,  and  expensive.  With  it  the  gravel,  to  be  profitable,  must 
be  sufficiently  rich  to  return  at  least  2  dwts.  per  day  per  labourer. 
Du  Bois,  however,  estimates  that  a  yield  of  3s.  4d.  (2  florins)  per 
man  per  day  would  cover  all  working  expenses.  This  sum  would 
require  gravel  of  a  tenor  of  about  45  grains  per  cubic  yard. 


a  Granger,  Trans.  Amer.  Inst.  M.E.,  XXVI,  1896,  p.  516  ;  Hennecke,  Zeitsch. 
Berg-Hiitt.  und  Sal.,  XLVI,  1898,  p.  252 ;  Du  Bois,  "  Geologisch-bergmanniscke 
Skizzen  aus  Surinam,"  Freiberg  i.  S.,  1901,  pp.  1-112. 


640 


SOUTH    AMERICA. 


In  1896  the  six  principal  placers  had  yielded  a  little  over  a 
million  sterling,  divided  as  follows  : — 


Barnett's 

Green's 

Mueller  and  De  Jong's 

Solomon's 

Montana 

Savanna 


£(300,000 

200,000 

100,000 

100,000 

50,000 

30,000 


In  1897  the  principal  producing  rivers  with  their  yields  were  :- 


Surinam 
Saramacca . 
Marowyn 
Lawa 


13,97-4  ounces. 
4,356       ,, 
2,456       „ 
1,479       „ 


The  gold-gravels  here,  as  in  the  other  Guianas,  are  often 
concealed  beneath  a  lateritic  surface  layer.  The  gold,  moreover, 
is  occasionally  disseminated  through  the  more  impure  laterite. 
The  average  fineness  of  Dutch  Guiana  placer  gold  is  926.  Dredging 
methods  have  recently  been  tried,  but  no  information  as  to  their 
success  or  otherwise  is  available. 

The  rocks  of  Dutch  Guiana,  as  indicated  on  the  geological 
sketch-map  accompanying  the  treatise  by  Du  Bois,  already  cited, 
are  mainly  crystalline  schists,  phyllites,  and  ancient  sedimentary 
rocks,  with  which  are  associated  extensive  exposures  of  granite, 
gneiss,  and  diabase.  Search  for  gold-quartz  veins  is  a  matter  of 
extreme  difficulty  in  the  dense  tangled  forests  of  Guiana,  but  veins 
of  a  fairly  high  tenor  have,  nevertheless,  been  found.  These  occur 
in  the  crystalline  schists  and  phyllites,  especially  where  the 
metamorphic  rocks  have  been  intruded  by  igneous  dykes.  Yet 
quartz  veins  in  intrusive  diabase  or  diorite  or  in  granite  have  so 
far  been  found  to  be  either  barren  or  to  be  too  poor  to  be  profitably 
worked.  The  gold-quartz  veins  of  the  neighbourhood  of  the  De 
Jong  and  Guyana-Goud  placer  deposits  He  in  phyllites.  The  country 
is  highly  weathered  ;  the  veins  traversing  it  carry  an  oxidised  zone 
to  depths  of  about  100  feet.  The  average  width  of  the  veins  is 
from  1  to  3  feet.  The  gold  is  finely  disseminated  through  the  quartz 
and  is  associated  with  auriferous  pyrite,  which  often  impregnates 
in  addition  the  walls  of  the  vein. 

The  progress  of.  mining  in  Dutch  Guiana  has  been  greatly 
hindered  by  the  lack  of  transport  facilities.  A  railway  to  the  gold- 
fields  was  in  course  of  construction  in  1907. a 


"  Middelburg,  Min.  Jour..  April  4,  1908,  p.  407. 


DUTCH   GUIANA. 


641 


The  total  gold  production  of  Dutch  Guiana  from  1879  to  1900 
inclusive  was  536,220-2  ounces  (16,678-716  kg.).  Since  1900  there 
have  been  produced  the  following  : — 


Year. 

Kg. 

Ounces. 

Value,  Sterling. 

1901 

753 

21,209 

£85,949 

1902 

587 

18,872 

67,085 

1903 

682 

21,926 

77,918 

1904 

882 

25,784 

91,548 

1905 

1,071 

34,883 

116,848 

1906 

1,188 

38,194 

129,611* 

1907 

1,085 

34,882 

118,373* 

••  Estimated. 


FRENCH  GUIANA  (Cayenne). 

The  general  geology  of  French  Guiana,  as  of  the  other  Guianas, 
may  be  briefly  outlined  as  a  complex  of  Archaean  and  metamorphic 
rocks  lying  in  the  hinterland,  with  Tertiary  or  more  recent  sedi- 
mentary rocks  nearer  the  coast.  Only  minor  modifications  of  the 
foregoing  statement  are  necessary.  Devonian  limestones  outcrop 
not  far  from  Cayenne,  and  Silurian  slates  are  known  in  the  Mana 
valley.  The  ancient  metamorphic  rocks  comprise  gneiss,  talc- 
schist,  mica-schist,  amphibolite,  slate,  &c.  These  are  intruded 
by  granite  and  pegmatite,  and  also  by  diabase  and  diorite,  the 
latter  also  occurring  in  flows. a 

The  quartz  veins  of  French  Guiana  are  met  with  in  the  older 
schists  and  also  in  the  diorites,  forming  often,  as  is  also  the  case  with 
quartz  veins  in  similar  rocks  on  the  Ankobra  river,  West  Africa,  bars 
or  falls  in  the  courses  of  the  rivers.  The  veins  vary  in  width  from  a  few 
inches  to  several  feet.  Their  quartz  is  ordinarily  milky- white  in  colour, 
but  when  rich  it  assumes  a  bluish  tint."  Pyrite  and  mispickel  are 
abundant.  Levat  concludes  that  the  majority  of  these  veins  are 
barren,  and  that  it  is  only  in  the  neighbourhood  of  diorites  and 
diabase  (as  at  Adieu- Vat)  that  they  become  auriferous.  The  diorites 
and  diabases  of  French  Guiana  are  often  highly  impregnated  with 
pyrites,  and  in  such  cases  are  themselves  auriferous.  The  proportion 
of  pyrites  present  may  reach  5  per  cent,  of  the  total  weight  of  the 
rock.  The  auriferous  content  of  these  basic  rocks  as  determined 
by  Levat, b  varied  from  1  to  1J  dwts.  per  ton,  and  depended,   as  a 

a  Levat,  Revue  Scientifique,  Ser.  4,  IX,  1898,  p.  705  ;  Id.,  Ann.  des  Mines,  Ser.  9, 
XIII,  1898,  p.  386  ;  Pelatan,  "  Les  Richesses  Minerales  des  Colonies  francaises,"  Paris, 
1902,  p.  42. 

"  Loc.  cit.,  p.  415. 
Rl 


642  SOUTH    AMERICA. 

rule,  on  the  amount  of  pyrites  present.  A  sample  of  diorite  from 
Maripa  yielded  the  exceptionally  high  return  of  15  dwts.  gold  per 
ton,  but  in  this  case  free  gold  was  noted  in  the  rock  prior  to  assay. 
Granitic  intrusions  on  the  other  hand  appear  to  be  barren.  Similar 
diorites  to  the  foregoing  occur  in  all  the  Guianas,  from  the  famous 
El  Callao  mine  in  Venezuela  in  the  west  to  the  Carsavene  fields  in 
the  Disputed  Territory,  north  of  the  Amazon,  in  the  east — a  total 
distance  of  some  650  miles.  It  therefore  becomes  obvious  that  we 
are  here  dealing  with  a  single  petrological  province,  in  which  the 
intrusion  of  basic  rocks  is  genetically  connected  with  auriferous 
impregnation.  The  subject  has  been  dealt  with  at  length  in  an 
earlier  section  of  this  volume,  and  will  not  be  further  pursued  in 
this  place. 

Only  one  gold-quartz  mine  in  French  Guiana  has  attained 
any  measure  of  success.  It  belongs  to  La  Societe  Anonyme  de  St. 
Elie,  operating  at  Adieu- Vat  on  the  Sinnamari  river.  Its  veins  are  in 
greatly  weathered  dioritic  rock,  the  zone  of  weathering  extending 
to  a  depth  of  80  feet.  The  veins  are  from  1\  to  4  feet  in  thickness 
and  are  of  high  tenor,  ranging  from  2\  to  3  ounces  per  ton  over 
several  thousand  tons.  Work  was  commenced  at  Adieu- Vat  about 
1878,  and  in  1885  a  small  20-head  stamp  mill  was  erected  and 
treated  some  2,500  tons  of  2-ounce  stone,  leaving  from  6  to  30  dwts. 
gold  per  ton  in  the  tailings.  The  ore-shoot  soon  gave  out, 
and  operations  then  ceased.  In  1890  the  mine  was  re-opened  for 
a  short  time,  when  10  tons  of  7^-ounce  stone  were  extracted.  The 
mine  was  being  worked  again  in  1905.  With  a  capital  of  £160,000 
La  Societe  Anonyme  de  St.  Elie  had  paid  in  dividends  to  its  share- 
holders no  less  than  £191,724  between  the  years  1878  and  1898. 

In  the  Disputed  Territory  the  bed-rock  of  the  rich  placers 
is  amphibolite  and  amphibolite  gneiss,  through  which  are  intruded 
diorites  that  are  sometimes  porphyritic  and  are  often  epidotised. 
The  diorites  contain  veins  of  quartz  and  thin  intrusions  of  pegmatite 
(granulite),  the  latter  carrying,  as  accessory  minerals,  garnet  and 
hornblende.  Both  the  quartz  and  the  granulitic  veins  are  auriferous, 
but  the  gold  is  always  intimately  associated  with  the  quartz  even 
in  the  granulites.a 

Nearly  all  the  gold  of  French  Guiana  is  derived  from  its  placer 
deposits.  The  earliest  discovery  of  alluvial  gold  appears  to  have 
been  made  in  1853  by  a  Brazilian  prospector,  who  had  settled 
on  the  upper  waters  of  the  Approuague  river.  The  auriferous 
gravels  occur  along  the  present  valley  bottoms  and  are  of  com- 
paratively recent  origin.  The  richest  placers  are  found  distributed 
along  the  course  of  the  diabasic  and  dioritic  intrusions  through  the 


a  Levat,  loc.  cit.,  p.  437. 


FRENCH   GUIANA.  643 

country,  and  also  along  folds  produced  in  the  quartzose  schist 
by  the  basic  intrusions.  All  streams  radiating  from  such  areas  are 
likely  to  contain  gold.  These  conditions  are  fulfilled  in  the  case  of 
the  St.  Elie,  Dieu-Merci,  Elysee,  Pas-Trop-Tot,  Lawa,  and  other 
placers. 

A  vast  extent  of  the  lower  country  is  covered  with  a  lateritic 
deposit  (roche  a  ravets),  which  is  occasionally  auriferous.  Samples 
of  this  rock  yielded  on  assay  to  Levat  tenors  of  1^  to  4i  dwts.  per 
ton,  with  two  exceptionally  high  assays  of  116  dwts.  and  2\  ounces 
per  ton  respectively.  It  was  in  such  a  ferruginous  rock  that  the 
largest  nugget  found  in  the  colony  was  obtained.  It  weighed  530 
ounces,  and  was  coated  with  iron  oxide.  Levat  compares 
these  lateritic  deposits  with  the  jacutinga  and  canga  of  Brazil, 
but  there  is  no  real  analogy  except  in  the  high  percentage  of  ferru- 
ginous matter.  On  the  other  hand,  an  analogy  between  the  older 
rocks  of  the  two  countries  is  sound. 

With  native  labour  and  under  favourable  conditions  a  gold 
content  of  at  least  1£  dwts.  per  cubic  yard  (3  grammes  per  cubic 
metre)  is  required  in  order  to  return  a  profit.  A  party  of  12  workers, 
of  whom  four  are  diggers,  will  not  treat  more  than  6  to  8  cubic 
yards  per  diem.  The  gold  is  ordinarily  somewhat  coarse,  and  nuggets 
of  \  to  1^  ounces  are  by  no  means  rare. 

Since  the  only  traffic  routes  of  the  country  lie  along  the  water- 
ways, it  is  only  near  these  that  placers  have  been  discovered.  Taking 
the  placer  districts  of  the  colony  in  order  from  west  to  east,  the  first 
is  the  Marowyn  (Maroni),  the  boundary  river  between  Dutch  and 
French  Guiana.  It  was  to  one  of  its  main  tributaries,  140  miles 
from  its  mouth,  that  the  great  Lawa  rush  took  place  in  1889.  The 
ownership  of  the  Lawa  territory  was  long  in  dispute  between  France 
and  Holland,  but  was  finally  awarded  to  the  latter  country.  It 
still  remains  one  of  the  richest  placers  in  the  Guianas.  Next  to  the 
east  is  the  Mana  district,  worked  since  1879.  Then  follow  in  order, 
the  Sinnamari,  Kourou,  Comte,  Approuague,  Oyapok,  and  finally, 
the  Carsavene  district,  on  the  river  of  that  name,  and  in  the  disputed 
Franco-Brazilian  territory  north  of  the  Amazon. a  The  plac*ers 
of  the  last  were  extraordinarily  rich,  the  two  discoverers,  after 
only  two  months'  work,  obtaining  in  1893  nearly  10,000  ounces 
(300  kg.)  gold.  The  news  of  this  yield  naturally  caused  a  rush, 
in  which  many  thousands  participated.  In  1907  the  yield  from  the 
district  was  inconsiderable. 

Until  1905  all  the  alluvial  gold  recovered  had  been  obtained 
by  crude  methods  of  sluicing,  but  in  that  year  a  small  dredge  was 

a  Katzer,  Oesterr.  Zeit.  fur  Berg-  und  Hiitt.,  1897,  p.  295  ;   Id.,  Zeit.  fur  prakt.  Geol., 
y,  1897,  p.  422. 


644 


SOUTH    AMERICA. 


erected  on  the  Courcibo  river,  a  tributary  of  the  Sinnamari.  For 
some  time  it  gave  good  returns,  but  was  eventually  sunk  during 
a  flood.  Two  dredges  were  in  operation  in  1907  on  the  Elysee 
placer  on  the  Lezard  river,  a  left  tributary  of  the  Mana.  The 
Lezard  valley  is  here  from  100  to  400  yards  wide.  The  bed-rock 
lies  at  a  depth  of  some  12  to  16  feet.  Heavy  black  sand  is  very 
abundant,  sometimes  forming  10  per  cent,  of  the  wash.  Assays 
of  the  black  sand  showed  gold  tenors  of  from  U  to  15  ounces  gold 
per  ton.a 

From  1868  to  1899  inclusive  the  officially  estimated  gold- 
yield  of  French  Guiana,  based  solely  on  the  amount  of  duty  paid 
(8  per  cent.),  was  1,920,608  ounces  (59,739  kg.)  worth  £7,168,680. 
For  obvious  reasons,  not  all  the  gold  produced  is  declared  for  duty, 
and  to  the  foregoing  figures  at  least  a  third  is  to  be  added,  making 
the  total  production  of  the  colony  for  the  32  years  stated  worth 
about  10  millions  sterling.  Since  1899  the  following  returns  have 
been  declared  : — 


BRAZIL. 

The  chief  auriferous  region  of  Brazil  extends  from  Bahia  in  the 
north  to  Goyaz  in  the  south.  Gold-bearing  districts  of  minor 
importance  are  met  with  in  the  States  of  Matto  Grosso,  Rio  Grande 
do  Sul,  Sao  Paulo,  Parana,  Ceara,  Para,  and  Maranhao.  The  gold 
deposits  of  the  Disputed  Territory  north  of  the  Amazon  have 
already  been  mentioned  under  French  Guiana. 

Placer  Deposits. — In  Matto  Grosso  gold  has  long  been  worked 
in  the  lateritic  ferruginous  conglomerate  of  the  Cuyaba  district, 
but  these  deposits  are  now  on  the  point  of  exhaustion.  Gold-quartz 
veins  traverse  the  slates  of  the  district,  but  are  not  of  high  tenor. 
Nevertheless,  their  denudation  and  that  of  the  ferruginous  con- 
glomerate has  furnished  gold  to  the  rivers,  and  principally  to  the 


vaux,  Eng.  Mia.  Jour.,  March  2,  1907,  p.  421  ;    Id.,  Bull.  Soc.  des  Ingenieurs. 
Civ.  de  France,  Feb.,  1908. 


BRAZIL.  645 

Coxipo-de-Ouro,  which  flows  into  the  Cuyaba."  The  gravels  of  this 
river,  after  having  been  worked  for  many  years  by  native  methods, 
were  attacked  in  1902  by  dredging,  with  apparently  successful 
results.6  The  workable  portions  of  the  river  vary  from  80  to  200 
feet  in  width  with  a  thickness  of  2  to  25  feet,  and  have  a  total 
length  of  40  to  100  miles.  All  the  pay-gravel  is  in  the  present 
river  bed.  No  boulders  occur  in  the  wash.  Both  gold  and  diamonds 
are  saved.  The  value  of  the  wash  treated  is  about  3Jd.  per  cubic 
yard.  The  gold  is  fine,  and  is  worth  about  £4  per  ounce.  Dredging 
conditions  are  on  the  whole  very  favourable.0 

Elsewhere  in  Brazil  dredging  ground  is  known  to  occur  on  the 
Piracicaba  river,  which  flows  from  near  Sao  Paulo  into  the  Rio 
Tiete,  a  tributary  of  the  Parana.  In  the  province  of  Minas  Geraes 
dredges  are  in  operation  on  the  Rio  das  Mortes  and  the  Ribierao  do 
Carmo. 

The  date  of  the  first  discovery  of  gold  in  Brazil  is  doubtful. 
The  discovery  has  been  credited  to  a  paulista  (half-breed)  named 
Antonio  Rodriguez  Arzao,  who  is  believed  to  have  washed  gold  in 
1693  in  the  Caethe  district.  Other  authorities  ascribe  the  first 
discovery  to  another  paulista,  Antonio  Dias,  working  in  the  placer 
deposits  in  Minas  Geraes  near  the  town  now  known  as  Ouro  Preto. 
The  date  of  his  discovery  is  believed  to  be  1699.  In  1718  the  Cuyaba 
placers,  or,  rather,  those  of  the  Coxipo-de-Ouro  river,  flowing  into 
the  Cuyaba,  in  the  Matto  Grosso  region,  became  known.  Six 
years  later  similar  auriferous  deposits  were  found  in  the  region 
now  forming  the  State  of  Goyaz,  to  the  east  of  Matto  Grosso.  The 
royalty  imposed  by  the  Crown  of  Portugal  was  one-fifth,  and  was 
the  same,  therefore,  as  the  quinto  paid  to  Spain  in  the  case  of 
Mexico,  Panama,  and  the  northern  Spanish  colonies  of  South 
America.  In  1817  the  Baron  von  Eschwege,  a  Prussian  savant 
engaged  by  the  Governor  of  Brazil  to  improve  mining  and  metal- 
lurgical methods  in  Brazil,  opened  up  the  mines  of  Passagem,  near 
Marianna,  after  the  most  approved  methods  then  in  vogue,  at  the 
same  time  erecting  the  first  gold-milling  stamps  worked  in  Brazil. 
Previous  to  that  year  the  methods  of  mining  and  milling  were  crude 
in  the  extreme,  the  quartz  crushed  by  hand  being  laboriously 
washed  by  the  batea.  Indeed,  the  washing  in  the  batea  has  survived 
to  the  present  day,  but  is  employed  only  on  free-milling  ores  with 
coarse  gold.^ 

a  Evans,  Q.J.G.S.,  L,  1894,  p.  102. 

h  Eng.  Min.  Jour.,  March  2,  1907,  p.  419. 

c  Booth,  Min.  Jour.,  May  9,  1908,  p.  562. 

*  For  a  complete  bibliography  of  Brazilian  mineral  deposits  to  1903,  see  Branner, 
Archiv.  Mus.  Nacion.,  Rio  de  Janeiro,  XII,  1903. 


646  SOUTH    AMERICA. 

Rio  Grande  do  Sul. — The  Rio  Grande  do  Sul  is  the  most 
southerly  department  or  state  of  Brazil.  Its  auriferous  deposits 
lie  in  two  formations  :  (a)  in  veins  in  metamorphic  chloritic  schists, 
and  (b)  in  syenites.  The  former  are  in  the  western  portion  of  the 
Sierra  do  Herval,  south-west  of  Porto  Alegre,  the  capital  of  the 
department.  The  metamorphic  schists  are  associated  with  gneiss 
and  with  fine  and  coarse  porphyries.  The  veins  of  the  second  class, 
in  syenites,  are  grouped  more  particularly  in  the  neighbourhood 
of  Lavras,  at  the  head  of  the  Camacuam  river  and  37  miles  north 
of  the  railway  station  of  Bage.  The  matrix  of  the  auriferous  veins 
is  quartz,  but  gold  also  occurs  in  impregnations  in  the  decomposed 
syenite. a 

Mining  has  been  carried  on  since  1835  or  earlier,  the  first- 
discovered  gold-quartz  veins  being  situated  at  San  Antonio  de 
Lavras.  These  were  originally  worked  by  Brazilians,  then  by  an 
English  company,  by  which  they  were  eventually  abandoned. 
In  1898,  three  European  companies,  one  English  and  two  Belgian, 
resumed  work  in  the  vicinity  of  Lavras.  The  gold  occurs  mainly 
in  small  stringers  and  stockworks  of  veinlets  in  a  syenite,  that  near 
the  veins  is  decomposed  for  distances  of  6  feet  or  less  from  the 
walls.  The  gold  generally  occurs  in  pockets  and  is  associated  with 
galena,  pyrite,  and  blende.  Of  these,  galena  is  locally  considered 
the  best  indication  of  richness,  but  the  pyrite  is  also  auriferous 
and  may  reach  tenors  of  16  to  23  ounces  gold  per  ton  of  concentrates. 
At  Sao  Sepe,  north-north-east  of  Lavras  and  22  miles  north-west  of 
Caeapava,  numerous  quartz  veins  exist  over  an  area  of  50  square 
miles.  In  one  place  a  workable  gold-quartz  vein  traverses  the 
granite  and  the  metamorphic  rocks,  close  to  their  contact  with 
coal-bearing  beds  ;  coal  being  mined  in  this  case  not  more  than 
1,000  yards  away  from  the  vein.  It  is  indeed  used  to  drive  a  small 
5-head  stamp  mill.  The  Sao  Sepe  quartz  veins  vary  in  thickness 
from  1|  to  6|  feet.  The  gold  is  sometimes  visible,  and,  as  at  Lavras, 
is  found  in  pockets. 

Near  the  village  of  Dom  Pedrito,  west  of  Bage,  and  near  the 
Uruguayan  frontier,  unimportant  auriferous  veins  were  worked 
for  a  short  time  in  1887.  Within  3  miles  of  the  Barcellos  veins 
similar   auriferous  veins   are   known. 

The  most  important  copper  deposits  of  Rio  Grando  do  Sul, 
viz.,  those  of  Camacuam,  near  the  river  of  that  name,  contain  small 
quantities  of  gold  (perhaps  4  dwts.  per  ton).  The  auriferous  belt 
of  this  department  is  continued  south  into  Uruguay. 

Minas  Geracs. — Few  mines  or  deposits  of  economic  value 
exist  in  Brazil  beyond  the  boundaries  of  the  Minas  Geraes  State, 

"  Scott,  Trans.  Inst.  M.E.,  XXV,  1903.  p.  510. 


BRAZIL. 


647 


which  lies  to  the  north-north-west  of  Rio  de  Janeiro.  The  goldfield 
proper  is  some  80  miles  long  by  60  miles  broad,  lying  at  an  average 
altitude  of  some  4,000  feet  above  sea-level,  and  attaining  a  maximum 
of  6,410  feet.  The  auriferous  deposits  lie  along  the  Sierra  do 
Espinhaco,  a  range  of  mountains  running  north  and  south  to  the 


"7.  _5ife#g53W-*1  /   ■  j£<="Ven<ania 


Fig.  210.     Map  of  Auriferous  portion  of  Minas  Geraes  Province,  Brazil  (Scott). 

Sierra  do  Itacambira  and  the  Sierra  da  Mantiquiera  respectively. 
The  centre  of  this  district  is  about  200  miles  distant  from  Rio  de 
Janeiro,   with  which  it   is   connected  by  railway. 

The  oldest  rocks  of  the  region  are  apparently  gneisses  and 
granites,  having  an  extensive  development  along  the  base  of  the 
Sierra  do  Espinhaco,  from  Ouro  Preto  northward  to  beyond  Cocaes. 
These  rocks  are  generally  much  decomposed,  and  may  in  such  cases 


648 


SOUTH    AMERICA. 


be  occasionally  auriferous.  Derby a  has  described  extensive  old 
workings  in  an  extremely  decomposed  gneiss  in  the  Campanha 
and  Sao  Gonzalo  districts,  50  to  60  miles  south-west  of  Sao  Joao 
del  Rei.  These  mines  are  now  deserted  and  appear  to  have  attained 
their  greatest  productiveness  about  1818.  The  rock  is  a  dark,  highly 
micaceous,  schistose  gneiss,  with  many  thin  seams  of  quartzite 
that  in  places  form  beds  quite  a  yard  in  thickness.  True  quartz 
veins  do  occur,  but  these  are  nearly  always  barren.    Minor  exceptions 


Figs.  211  and  212.     A.  Section  through  Ouko  Preto  Mountain.     B.  Section  through  Passagem 

Mine  (Scott). 

1.  Granite  or  Gneiss.     2.  Micaceous  and  Talcose  schists.     3.  Schistose  quartzite.     4.  Auriferous 
Quartz  Lode.     5.  Argillaceous    schist.     6.  Itabirite.     7.  Limestone.     8.  Canga  or  Iron-ore 

conglomerate. 

to  this  rule  are,  however,  known.  The  valuable  portion  of  the 
gneissose  rock,  and  in  general  the  host  of  the  gold,  is 
that  which  contains  the  above-mentioned  quartzose  bands 
or  beds,  particularly  when  these  are  ferruginous.  Derby 
states  that  the  average  tenor  of  the  whole  mass  at  its 
principal  gold  occurrence  was  some  3|  grains  gold  per  ton. 
Magnetite,  together  with  a  few  grains  of  pyrite,  occurs  in  the  heavy 
residues  left  on  washing,  and  it  is  concluded  that  the  gold  was 


°  Amer.  Jour.  Sci.,  XXVIII,  1884,  p.  443. 


BRAZIL.  649 

originally  in  intimate  association  with  the  latter,  especially  in  view 
of  the  similar  relations  subsisting  between  gold  and  pyrite  in  the 
central  and  northern  portions  of  Minas  Geraes  in  the  auriferous 
schists,  quartzites,  and  itabirite  (haematite-mica-schist)  series.  In 
former  days  these  deposits  were  worked  after  the  same  manner  as 
placers.  A  company  formed  in  1884  to  work  the  Sao  Gonzalo 
deposits  by  hydraulicing  met  with  indifferent  success. 

Overlying  the  fundamental  granites  and  gneisses  of  the  province 
of  Minas  Geraes  is  a  series  of  micaceous  and  talcose  schists  of  possible 
Huronian  age.a  These  are  the  characteristic  gold-bearing  rocks 
of  Brazil.  They  are  not  themselves  auriferous,  but  are  traversed 
by  auriferous  quartz  veins.  The  schists  are  generally  very  much 
decomposed,  and  are,  therefore,  readily  affected  by  stream  waters, 
the  action  of  which  results  in  the  formation  of  deep  ravines. 
Associated  with  the  micaceous  members  of  the  series  are  schistose 
quartzites,  made  up  mainly  of  quartz  and  mica,  and  carrying,  in 
the  neighbourhood  of  Ouro  Preto,  gold-quartz  veins.  Argillaceous 
schists  also  occur  in  the  same  districts,  and  are  traversed  by  quartz 
veins  that  are  occasionally  auriferous.  In  places  these  schists 
become   chloritic.6 

Of  the  schistose  rocks  of  Minas  Geraes  the  micaceous  haamatite- 
quartzite  is  perhaps  the  best  known.  It  is  commonly  known  as 
itabirite,  and  is  essentially  a  mixture  of  specular  iron-ore  and 
magnetite  containing  a  variable  amount  of  quartz.  While 
generally  decidedly  schistose  it  may  also  be  found  either 
solidly  compacted  or,  on  the  other  hand,  loosely  granular. 
With  the  itabirite  are  associated  thin  beds  (1  to  8  inches 
thick)  of  sandy  micaceous  and  limonitic  iron-ore  containing 
yellowish  talc  and  earthy  oxides  of  manganese.  These 
beds  are  generally  friable,  and  appear  to  be  a  decomposition 
product  of  itabirite.  The  rock  is  locally  known  as  jacutinga.  The 
itabirite  is  occasionally  auriferous,  but  the  jacutinga  is  generally  so. 
The  two  most  important  mines  in  this  formation  are  Gongo  Socco 
and  Maquine.  Dolomitic  and  siliceous  limestones  rest  on  the 
itabirite  and  jacutinga  at  Ouro  Preto,  Gongo  Socco,  &c,  and 
contain  no  auriferous  veins.  Overlying  the  calcareous  members 
of  the  series  come  great  thicknesses  of  micaceous  schist.  These  are 
often  auriferous  and  have  been  largely  worked  in  former  days. 

The  primary  gold-deposits  of  Minas  Geraes  may  be  separated 
into  four  divisions  :  contact  lodes,  lodes  in  the  schists,  lodes  in  the 
quartzites,  and  jacutinga  lines  in  itabirite.     The  first  have  been 

a  Wappaeus,  "  Geograpliia  Physica  do  Brazil,"  Rio  de  Janeiro,  1884,  pp.  44-59. 

b  Scott,  Trans.  Amer.  Inst.  M.E.,  XXXIII,  1903,  p.  406,  et  seq.;    from  which  excellent 
account  many  of  the  details  here  given  are  derived. 


650  SOUTH   AMERICA. 

worked  since  the  earliest  days  of  vein-mining  in  Brazil.  They 
have  furnished  the  important  mines  of  Vellosa,  Pellucias,  Tassara, 
Passagem,  and  Morro  Santa  Anna.  Of  these  only  the  two  last  are 
still  being  worked.  These  contact  lodes  are  lenticular  masses  of 
quartz  interstratified  between  the  itabirites  and  the  underlying 
quartzites  or  between  the  itabirite  and  argillaceous  schist.  The 
lenses  are  much  longer  in  dip  than  in  strike,  but  vary  between 
30  and  300  feet  with  a  thickness  of  3  to  50  feet.  The  Passagem  lode  a 
lies  between  mica-schist  and  itabirite  and  is  parallel  to  the  strati- 
fication. The  lode  varies  in  thickness  between  6  and  50  feet.  Its 
vein  filling  is  quartz,  tourmaline,  and  arsenopyrite,  with  lesser 
quantities  of  pyrite  and  pyrrhotite.  Near  the  foot  wall,  where 
arsenopyrite  and  tourmaline  abound,  the  tenor  of  the  ore  may 
reach  6|  ounces  per  ton.  A  notable  feature  in  this  vein  is  the 
presence  of  zircon  and  monazite  of  contemporaneous  deposition 
with  the  ore.  Tourmaline  is  also  present  in  the  country  beyond 
the  lode.  Andalusite  crystals  deposited  in  the  lode-fissure  are 
largely  altered  to  or  replaced  by  sericite,  rutile,  arsenopyrite, 
and  pyrite.  The  whole  association  is  considered  by  Hussak  to 
indicate  an  igneous  intrusion,  but  the  foregoing  association  is  quite 
within  the  powers  of  formation  of  highly-heated  aqueous  solutions. h 
In  the  Passagem  and  similar  lodes  the  gold  is,  as  a  rule,  unevenly 
distributed  throughout  the  quartz,  the  tenor  varying  from  1^  dwts. 
to  7  ounces  per  ton.  The  higher  tenors  occur  only  in  the  presence 
of  arsenical  pyrites.  Nevertheless,  the  results  obtained  from  large 
quantities  of  quartz  at  Passagem  vary  little  from  year  to  year. 
The  Morro  Santa  Anna  mines  are  of  considerable  antiquity,  and  are 
shown  by  Mawe  on  his  route-map c  as  mines  of  some  importance. 
Morro  Santa  Anna  lies  east  of  Ouro  Preto  and  4  miles  north  of 
Passagem.  In  geological  and  mineralogical  characteristics  its  lode 
closely  resembles  that  of  Passagem. 

The  Passagem  and  Morro  Santa  Anna  mines  are  the  property 
of  the  Ouro  Preto  Company.  The  former  lies  about  4|  miles  east 
of  Ouro  Preto  (the  ancient  Villa  Rica).  It  was  worked,  as  has  already 
been  mentioned,  in  1817  by  the  Prussian  engineer,  Baron  von 
Eschwege.  From  April,  1884,  to  December,  1900,  this  mine  treated 
617,129  tons  ore  for  a  yield  of  220,661  ounces  gold,  or  an  average 
of  7-1  dwts.  per  ton.  In  1907  quartz  to  the  amount  of  72,703  tons 
was  treated,  yielding  24,500  ounces  crude  gold  worth  £97,872, 
or  a  yield  per  ton  of  26s.  lid.    Costs  of  treatment  were  22s.  lljd. 


a  Hussak,  Zeit.  fur  prakt.  Geol.,  1898,  p.  345. 
h  Lindgren,  Trans.  Amer.  Inst.  M.E.,  XXX,  1901,  p.  556. 
'  Travels  in  the  Interior  of  Brazil,"  1828,  p.  194. 


BRAZIL. 


651 


per  ton.     In  1906,  the  tonnage,  yield,  and  costs  were  all  slightly 
higher. 

Lodes  in  the  schists  furnish  the  greater  number  of  the  mines 
worked  at  the  present  time  in  Minas  Geraes.  Broadly  speaking, 
they  consist  of  lenticular  shoots  of  quartz  intercalated  in  the  country. 
In  depth,  they  have,  as  at  Morro  Velho,  considerable  persistence. 
The  quartz  contains,  in  addition  to  gold,   varying   quantities  of 


PLAN     OF      PASSAGEM      MINE 


3%f\.  Jk^L 


Fig.  213.     Plan  of  Passagem  Mhe,  Minas  Geraes,  Brazil. 


pyrite  and  pyrrhotite,  together  with  carbonates  of  lime,  magnesia, 
and  iron.  Of  this  type  of  lode  the  Morro  Velho  is  the  most  important 
example.  It  is  situated  in  the  north-west  of  the  auriferous  district 
and  a  few  miles  south-east  of  Bello  Horizonte.  It  is  owned  by  the 
St.  John  del  Rey  Company,  one  of  the  best-known  and  the  longest 
established  of  English  gold-mining  companies.  The  company  was 
formed  in  1830  with  a  capital  of  £165,000  to  work  a  lode  near  Sao 
Joao  d'el  Rei.  This  mine  was  abandoned  in  1834,  and  in  the  same 
year  the  company  commenced  work  on  the  present  Morro  Velho 


652  SOUTH    AMERICA. 

mine.  From  1834  to  1867  mining  was  conducted  after  native 
methods,  with  the  result  that  a  serious  cave  occurred  in  the  latter 
year,  leading  to  the  temporary  abandonment  of  the  mine.  During 
this  period  the  mine  had  produced  28  •  5  tons  gold  of  a  probable 
value  of  some  £3,163,500,  and  had  paid  in  dividends  £896,000 
on  a  paid-up  capital  of  £135,000.  Mining  was  resumed  in  1874, 
but  a  second  extensive  cave  occurred  in  1886.  From  1875  to  1884 
the  total  value  of  the  gold  extracted  was  £5,500,000,  while  £556,000 
had  been  distributed  as  dividends.  In  1901  the  value  of  the  ore 
being  crushed  was  £2.  6s.  6Jd.  per  ton.  There  were  crushed  140,855 
tons  for  a  yield  of  99,197  ounces  bullion  worth  £327,663.  For  the 
year  1907  there  were  treated  151,454  long  tons  of  ore  for  a  yield  of 
gold  worth  £324,882,  and  a  net  profit  of  £70,840  was  made.  The 
average  profit  of  the  six  preceding  years  had  been  £58,747. 

The  country  rock  is  everywhere  a  highly  sheared  calc-schist, 
that,  on  account  of  the  development  of  micaceous  and  chloritic 
material,  has  generally  been  described  as  a  mica-schist.  The 
dominant  carbonate  is  that  of  lime.  The  vein-filling  of  Morro  Velho 
contains  30  to  40  per  cent,  sulphides,  30  to  40  per  cent,  carbonates, 
and  20  to  30  per  cent,  quartz.  Pyrrhotite  is  the  principal  sulphide, 
followed  by  pyrite,  arsenopyrite,  and  chalcopyrite.  Galena  and 
blende  are  rare.  The  gangue  is  quartz  with  siderite,  dolomite, 
and  calcite,  the  proportion  of  the  carbonate  present  diminishing 
in  the  order  given.  Beautiful  crystals  of  albite  felspar  are  common 
in  the  vughs  and  cavities  of  the  Morro  Velho  lode.  Albite  also 
occurs  in  the  quartz.  Graphite  is  met  with.  The  ore  is  very 
irregular  in  its  gold  content.  Pure  quartz  is  seldom  auriferous,  nor 
are  the  sulphides,  except  in  the  case  of  arsenical  pyrites.  The 
richest  ore  is  a  mixture  of  quartz,  dolomite,  and  siderite,  with 
arsenical  pyrites  and  pyrrhotite.  The  enclosing  walls  of  the  lode, 
though  often  highly  pyritous,  rarely  carry  more  than  2  to  3  dwts. 
gold  per  ton,  and  that  only  at  the  contact.  The  proportion  of 
pyrrhotite  in  the  ore  is  on  an  average  28  ■  5  per  cent.  The  bullion 
obtained  is  790  to  810  fine.  The  quartz-body  or  chimney  of  Morro 
Velho  has  a  horizontal  length  of  600  feet  with  an  average  cross- 
section  of  45  feet.  It  has  been  followed  for  more  than  a  mile  on 
the  dip  and  for  3,100  feet  vertically. 

The  Rapasos  and  Cuyaba  mines  in  the  vicinity  of  Morro  Velho 
are  also  the  property  of  the  St.  John  del  Rey  Company.  They 
present  the  same  character  of  country  and  lode  as  does  Morro 
Velho.  At  Rapasos  the  itabirites  are  highly  charged  with  magnetite. 
They  are  further  traversed  by  diabase  dykes,  that  appear  to  have 
a  genetic   connection  with  auriferous   deposition. "      The   Cuyaba 

a  Berg,  Zeit.  fur  prakt.  Geol.,  X,  1902,  p.  83. 


BRAZIL.  653 

workings  are  on  a  bedded  deposit  of  pyrites  of  a  tenor  of  3  to  4  dwts. 
per  ton. 

The  Sao  Bento  mine  lies  a  few  miles  south-west  of  Santa 
Barbara.  Its  lode  is  intercalated  in  micaceous  schists.  The  lode- 
matter  is  a  siliceous  and  micaceous  iron-ore.  The  lode  is  some 
40  feet  in  width,  but  of  this  only  H  to  8  J  feet,  of  a  tenor  of  2  dwts. 
to  1  ounce  per  ton,  is  worth  working.  In  the  oxidised  zones  the  gold 
lay  in  a  ferruginous  granular  quartz  that  was  replaced  in  depth  by 
quartz  carrying  pyrite  and  arsenopyrite.  The  Santa  Quiteria 
mines  in  the  immediate  neighbourhood  show  features  similar  to 
those  of  Sao  Bento. 

The  Taria  mine,  a  short  distance  south  of  Morro  Velho,  is 
working  a  quartz-chimney  similar  to  that  of  Morro  Velho.  It  also 
lies  intercalated  in  mica-schist.  The  chimney  is  about  160  feet 
in  horizontal  length,  and  varies  between  6  and  33  feet  in  thickness. 
The  gold  is  associated  mainly  with  pyrites. 

The  lodes  of  the  third  type,  viz.,  those  in  quartzites,  are  now 
of  no  importance,  and  all  have  long  been  abandoned.  The  Catta 
Branca  appears  to  have  been  the  most  important. 

Of  lines  or  bands  in  jacutinga,  representing  the  fourth  type, 
the  most  famous  has  been  the  Gongo  Socco,  situated  16  miles 
west  of  Santa  Barbara.  It  was  first  worked  by  an  English  company 
in  1820,  and  it  was  its  great  success,  coupled  with  the  fact  that 
Latin  America  had  succeeded  in  throwing  off  the  Spanish  yoke, 
that  appears  to  have  directed  the  flow  of  British  capital  towards 
South  American  mines  in  the  fourth  decade  of  the  nineteenth 
century.  The  gold  of  Gongo  Socco  was  found  in  a  band  of  jacutinga 
that  never  attained  a  greater  thickness  than  7  inches.  In  its  wider 
parts  the  central  portions  were  composed  of  laminated  masses  of 
gold  weighing  from  a  few  pennyweights  to  many  ounces.  In  1830 
a  miner  is  said  to  have  extracted  a  single  capful  that  contained  300 
ounces  of  gold.  Some  two-thirds  of  the  gold  obtained  was  ex- 
ceedingly coarse  and  in  the  form  of  solid  masses,  plates,  and  threads. 
The  whole  of  the  adjacent  itabirite  carried  gold.  The  richer  quartz 
was  crushed  by  hand  and  washed  in  the  batea,  the  poorer  was 
put  through  crude  native  stamp-mills.  The  jacutinga  on  analysis 
contained  no  less  than  97  per  cent,  ferric  oxide.  The  mine 
was  exhausted  about  1846.  It  had  then  reached  a  depth  of  420 
feet.  The  English  company  had  paid  £90,000  for  the  mine,  and 
despite  the  crude  methods  of  mining  and  treatment  then  in  vogue 
had  recovered  between  1826  and  1839  no  less  than  £1,300,000  gold. 
From  1826  to  1856  the  total  yield  had  been  414,317  ounces  (12,837 
kg.)  gold." 

a  Scott,  loc.  cit.,  p.  422. 


654 


SOUTH   AMERICA. 


The  Maquine  mine  near  Morro  Santa  Anna  was  also  in  a 
jacutinga  band.  Its  history  is  similar  to  that  of  Gongo  Socco, 
for  it  was  abandoned  when  its  workings  had  reached  a  depth  of  700 
feet  on  the  dip.  Its  period  of  greatest  production  was  1867-8, 
when  2J  tons  gold  were  extracted  and  dividends  of  100  per  cent, 
were  paid.  The  average  value  of  the  ore  was  |-ounce  per  ton.  This 
successful  mine  was  also  the  property  of  an  English  company. 

A  third  productive  mine  in  jacutinga  was  the  Itabira,  near 
the  town  of  Itabira  do  Matto  Dentro.  Its  workings  dated  from  the 
middle  of  the  eighteenth  century. 

Near  the  town  of  Paracatu  on  the  north-west  frontier  of  Minas 
Geraes,  surface  deposits  of  gold  occur  in  decomposed  mica-schists, 
lateritic  conglomerate,  and  surface  soil,  the  first  being  the  richest. 
No  auriferous  veins  or  igneous  dykes  are  known  in  the  vicinity. 
These  deposits  were  highly  productive  from  1745  to  1825.  It  is 
estimated  that  their  annual  yield  for  this  period  was  31,065  ounces. a 
A  few  faiscedores  still  eke  out  a  scanty  living  from  the  rivers  in  the 
neighbourhood  of  Ouro  Preto  by  batea-washing,  but  the  native 
placer  industry  of  Brazil  is  insignificant. 

The  gold  product  of  Brazil,  which  is  indeed  almost  entirely 
derived  from  the  Minas  Geraes  department,  has  been  in  the  twentieth 
century  : — 


Year. 

Kg. 

Crude  Ounces. 

Value,  Sterling. 

1901 

4,012 

128,986 

£535,000 

1902 

3,971 

127,667 

432,706 

1903 

4,302 

138,309 

468,591 

1904 

3,871 

124,452 

418,309 

1905 

3,879 

124,710 

420,128 

1906 

4,548 

146,218 

485,794 

URUGUAY. 

Little  information  concerning  the  gold  mines  of  Uruguay  is 
available.  The  earliest  discovery  was  made  in  1842  at  Cufiapiru 
in  Tacuarembo,  in  the  north  of  the  republic,  and  these  mines  have 
been  worked  spasmodically  since  1867.  The  production  during  1900 
was  only  2,568  ounces.  The  general  geological  features  of  the 
auriferous  area  resemble  closely  those  of  the  Rio  Grande  do  Sul 
province  in  Brazil.  The  country  of  the  veins  is  composed  of  talcose 
and  chloritic  slates,  penetrated  by  diorite  dykes.  The  gold-quartz 
veins  are  small,  but  near  the  outcrops  carry  gold  to  the  extent  of 

a  Pearson,  Trans.  Inst.  M.E.,  XXXI,  1906,  p.  258. 


URUGUAY.  655 

3  ounces  per  ton.  Hitherto,  the  tenor  has  been  found  to  diminish 
rapidly  at  depths  as  shallow  as  20  to  35  feet.  It  is,  therefore, 
locally  believed  that  when  a  vein  shows  no  gold  at  the  outcrop 
it  is  useless  to  sink  on  it  in  the  hope  of  finding  ore-shoots.  Much  of 
the  gold  is  free,  but  auriferous  pyrite  and  chalcopyrite  are  also 
found.  The  principal  mines  are  those  of  Sao  Gregorio  and  Cuiiapiru. 
In  addition  to  the  small  gold-quartz  veins  great  barren  reefs  with 
quartz  of  a  glassy  or  chalcedonic  aspect  are  known  to  traverse 
the  auriferous  areas. a  At  Cuiiapiru,  in  1907,  there  were  treated 
18,028  metric  tons  quartz  for  a  yield  of  117 "  917  kg.  (3.667  ounces) 
gold,  or  a  little  more  than  4  dwts.  per  ton.  This  amount  probably 
represents  the  total  yield  of  the  republic. 


ARGENTINA. 


The  gold  districts  of  the  Argentine  Republic,  with  the  exception 
of  those  in  Tierra  del  Fuego  (described  with  the  Chilian  occurrences 
of  that  region),  are  situated  on  the  western  slopes  of  the  Andes. 
The  best  known  are  those  of  the  Sierra  de  Famatina  in  the  Rioja 
Province,  somewhat  north  of  the  30th  parallel  of  south  latitude. 
As  far  back  as  1824  an  English  company  (the  Famatina  Mining 
Company)  commenced  work  there,  but  eventually  succumbed  to 
the  difficulties  engendered  by  the  geographical  and  political  con- 
ditions obtaining.    The  region  is  barren,  and  there  is  neither  animal 
nor  vegetable  life,  while  water  is  obtainable  only  by  the  melting  of 
snow  or  ice.     The  veins  are  essentially  cupriferous  but  contain  also 
gold  and  silver.  According  to  Bodenbender  b  the  veins  are  probably 
to   be     associated     in     origin   with   neighbouring     andesites.      So 
precipitous  are  the  mountains  that  the  mines  can  be  worked  on  an 
extensive  modern  scale  only  by  aerial  tramways.    These  have  been 
erected    by  the  Argentine  Government  -and    converge  mainly  on 
Chilecito  at  the  head  of  the  railway  line.     The  Famatina  mines  are 
primarily  copper  mines  containing  from  8  to  10  dwts.  gold  per  ton. 
A  successful  commencement  was  made  in  1908  in  the  smelting  of 
these  ores.    Gold  is  also  found  in  Argentina  in  the  provinces  of  San 
Luis,  San  Juan,  Tucuman,  Catamarca,  Salta,  and  Jujuy.    Dredging 
in  the  northern  rivers  has  not  hitherto  been  successful,  and  better 
results  are  expected  from  the  eastern  portion  of  Tierra  del  Fuego, 
which  lies  within   Argentine  jurisdiction. 

a  Fuchs  and  De  Launay,  "  Traite  de  Gifces  Mineraux,"  Paris,  1898,  p.  910  ;    Scott, 
Trans.  Amer.  Inst.  M.E.,  XXV,  1903,  p.  516  ;    Bodenbender,  "  El  Oro,"  Cordoba,  1902 
p.  41. 

b  "  El  Oro,"  Cordoba,  1902,  p.  41. 


656  SOUTH    AMERICA. 

Auriferous  quartz  veins  occur  in  the  Archaean  rocks  in  gneiss 
and  crystalline  schists  with  granite  and  diorite  in  the  Sierra  de 
Cordoba  (Candelaria  mines),  in  the  San  Luis,  Tucuman,  and 
Catamarca  provinces  ;  in  Silurian  or  Devonian  limestone  in  the 
province  of  San  Juan  (Gualilan  Guachi)  ;a  and  in  slates  of  similar 
age  in  the  province  of  Jujuy  and  possibly  associated  with  acid 
plutonic  rocks.  Alluvial  auriferous  deposits  occur  in  the  Jujuy 
province  ;  at  Famatina ;  and,  as  already  stated,  in  the  eastern  portion 
of  Tierra  del  Fuego. 

Among  the  more  recently  reported  auriferous  fields  are  those 
of  the  Neuquen  territory,  and  near  Chosmalal  at  the  head  of  the 
Neuquen  river  in  the  Cordilleras.  The  auriferous  area  is  said  to  be 
large.  It  has,  however,  been  worked  for  many  years  by  the  Chilians 
using  primitive  methods  of  ground-sluicing. h 

CHILE. 

The  auriferous  veins  of  Chile  have  been  broadly  divided  by 
Moricke  c  into  two  main  classes  :  (a)  Auriferous  veins  proper, 
that  are  worked  entirely  for  their  gold,  as,  Guanaco  in  the  province 
of  Antofagasta  ;  Inca  de  Oro,  Cachiyuyo,  and  Jesus  Maria  in  the 
province  of  Atacama ;  Talca,  Andacollo,  and  Los  Sauces,  in 
the  province  of  Coquimbo ;  Mina  Chivato  in  the  province 
of  Talca ;  &c.  ;  and  (b)  auriferous  copper  deposits  in 
which  the  gold  is  subordinate  in  value  to  the  baser  metal,  e.g., 
Remelinos  and  Ojancos  in  the  province  of  Atacama  ;  Tamaya 
and  La  Higuera  in  the  province  of  Coquimbo  ;  Las  Condes  and  Pera- 
lillo  in  the  province  of  Santiago,  &c.  The  deposition  of  gold  in 
the  case  of  the  first  group  appears  to  be  closely  connected  with  the 
acid  eruptive  rocks  of  the  Chilean  coast  ranges,  a  connection  which 
may,  indeed,  be  traced  with  a  few  breaks  from  the  far  north  of 
Chili  to  and  beyond  Valdivia  in  the  south.  The  connection  is, 
however,  more  or  less  continuous  and  obvious  from  Taltal  to  some 
distance  south  of  Concepcion.  Near  Valdivia  gold-quartz  veins 
occur  in  mica-schist.  At  Lake  Villa  Rica,  north-east  of  Valdivia, 
the  Spaniards  worked  a  rich  gold  mine  whose  veins  apparently 
lay  in  granite. 

Three  Chilean  goldfields  lie  on  or  a  little  to  the  south  of  the  25th 
parallel  of  south  latitude.  These  are  the  Paranao,  42  miles  north 
of  the  seaport  of  Taltal  ;  Guanaco,  80  miles  north-east  of  Taltal  ; 
and  the  Sierra  Overa,  63  miles  south-west  of  Taltal.     The  Guanaco 

a  Bodenbender,  loc.  cit. 

"  For  a  detailed  description  of  the  metalliferous  occurrences  of  the  Argentine  Republic, 
see  Hoskold,  "Official  Report  on  Mines,  &c,  of  the  Argentine  Republic,"  Buenos 
Ayres,  1904. 

c  Berichte  der  Naturfor.  Gesell.,  Freiburg  i.  B.,  X,  1898,  p.  152. 


CHILE.  657 

field  lies  in  the  barren  waterless  Atacama  desert,  perhaps  the  most 
arid  in  the  world.  Its  mines  are  situated  at  an  altitude  of  more 
than  9,000  feet  above  sea-level,  and  are  confined,  with  the  exception 
of  a  rich  chimney  in  a  small  hill  3  miles  away,  to  two  small  hills 
(Guanaco  and  Guanacito)  rising  abruptly  from  the  desert  level. 
No  other  gold  veins  are  known  to  exist  within  a  radius  of  50  miles. 
The  mines  were  discovered  in  1885.  The  country  of  the  gold 
veins  is  liparite  (quartz-trachyte).™  The  rock  is  normally  greatly 
decomposed,  but  in  its  original  state  was  apparently  a  brownish 
somewhat  porphyritic  rock  with  glassy  modifications  (perlitic 
pitchstones).  The  gold  occurs  as  very  fine  particles  strewn  through- 
out the  mass  of  the  rock,  which  is  now  almost  completely  silicified. 
Even  when  the  rock  has  a  tenor  of  hundreds  of  ounces  gold  per  ton, 
the  gold  itself  is  rarely  visible.  Gold  of  secondary  origin  occurs  in 
fissures,  in  cleavage  planes  in  kaolinite,  as  fine  grains  in  cellular 
rock,  and  as  brilliant  spangles  on  barytes  crystals.  The  last  are 
occasionally  covered  by  a  thin  layer  of  clear  crystallized  quartz, 
through  which  the  gold  may  be  seen.  After  the  general  silicification 
of  the  country,  barytes  has  been  deposited  in  fissures,  as  also  has 
scorodite  (hydrous  ferrous  arseniate).  In  depth  tetrahedrite  is 
found,  and  its  oxidation  gives  rise  near  the  surface  to  copper  silicates 
and  copper  carbonates.     The  average  fineness  of  the  gold  is   944. 

The  ore-bodies  of  Guanaco  have  no  definite  shape,  the  nearest 
approach  to  regularity  being  assumed  by  the  bodies  locally  termed 
mantos — oval,  flattened  lenses  of  quartz,  pink  or  grey  in  colour, 
and  themselves  disposed  through  the  country  without  any  indication 
of  system.  The  deposits  appear  to  have  little  permanence  in  depth, 
the  rich  deposits  that  have  hitherto  been  found  lying  less  than 
120  feet  from  the  surf  ace. h  According  to  Moricke  the  primary 
source  of  the  free  gold  is  the  liparite  itself,  and  not,  as  might 
naturally  have  been  expected,  siliceous  solutions  containing 
gold  resulting  from  the  oxidation  of  auriferous  pyrite  or  other 
sulphides. 

The  Sierra  Overa  gold  region,  63  miles  south-west  of  Taltal,  and 
5,600  feet  above  sea-level,  differs  from  that  of  Guanaco  inasmuch 
as  its  gold  lies  in  highly  ferruginous  banded  crystalline  quartz 
veins  in  diorite.  To  depths  of  at  least  300  feet  the  ore  is  free-milling 
with  little  or  no  pyrite.  The  gold  occurs  fairly  evenly  distributed 
through  the  quartz,  and  also  is  occasionally  found  impregnating  the 
country  beside  the  veins.  The  last  vary  in  width  from  a  few  inches 
to  3  feet.     One  vein,  8  feet  in  width  had,  at  a  depth  of  300  feet,  an 


a  Kaiser,  Verb,  naturh.  Verein.  Preuss.  Rheinl.,  LVI,  1899,  p.  31  ;    Moricke,  loc. 
cit.  sup. 

6  Loram,  Trans.  Amer.  Inst,  M.E.,  XXIX,  1899,  p.  489. 

Si 


658  SOUTH   AMERICA. 

assay  value  of  nearly  £13  per  ton.  The  Sierra  Overa  field  was 
discovered  only  in  1893,  and  its  subsequent  progress  has  been 
considerably  retarded  by  the  absence  of  water  and  the  difficulties 
of  access." 

The  district  of  Andacollo  is  the  richest  and  most  important, 
from  the  point  of  view  of  gold  production,  in  Chile.  It  is  situated 
about  40  miles  south-west  of  the  port  of  Coquimbo,  and  lies  on  the 
flanks  of  a  barren  mountain  chain  some  3,250  feet  above  sea-level. 
Its  placers  have  been  worked  since  the  days  of  the  Incas,  and  from 
them  the  early  Spanish  adventurers  also  obtained  great  quantities 
of  gold.  Even  at  the  present  day  a  considerable  amount  of  alluvial 
gold  is  recovered  by  the  inhabitants,  but  the  principal  modern 
source  of  the  gold  of  Andacollo  lies  in  its  gold-quartz  veins,  that, 
like  the  irregular  quartz  bodies  of  Guanaco,  traverse  liparite  or 
quartz-porphyry.  For  the  most  part,  the  veins  of  Andacollo  are 
true  gold-quartz  veins,  but  auriferous  pyrites-veins  are  also  known. 
Pyrite  is  scattered  throughout  the  rock-mass,  as  also  is  chalcopyrite, 
but  the  latter  is  not  abundant. 

The  ores  of  Canutillo,  north  of  Taltal  and  15  miles  south  of 
Freirina,  in  the  Atacama  province,  were  mined  by  the  Incas  between 
1430  and  1470.  In  1535  the  country  fell  into  the  hands  of  the 
conquistadores,  and  the  gold  mines  were  worked  with  great  profit 
for  some  time.  Mining,  however,  ceased  until  1700,  when  the  rich 
oxidised  zones  were  opened  up.  After  a  century  these  in  turn 
were  exhausted,  and,  with  the  political  troubles  of  the  early  years 
of  the  nineteenth"  century,  the  mines  were  again  abandoned,  not 
to  be  re-opened  until  the  advent  of  an  American  company  in  1896. 
The  country  is  augite-diorite,  intrusive  through  hornblende-schist. 
The  age  of  the  intrusive  rock  is  probably  lower  Tertiary.  The  veins 
exist  only  in  the  diorite,  and  in  no  case  pass  out  into  the  schists. 
They  vary  in  width  from  a  few  inches  to  10  feet.  In  the  upper  levels 
the  gold  is  free.  In  the  sulphide  zone  it  is  associated  with  pyrite 
and  arsenopyrite.6 

The  La  Higuera  mines  in  the  province  of  Coquimbo  are  working 
on  gold-copper  veins.  Next  to  the  Tamaya  mines,  they  are  the  most 
important  of  the  auriferous  copper-pyrites  workings  in  Chile. 
The  country  here,  as  at  Tamaya,  is  a  quartz-bearing  gabbro-diorite, 
associated  with  a  normal  quartz-diorite.  The  gold-copper  veins 
of  La  Higuera  occur  in  the  latter  variety  of  diorite.  Both  at  La 
Higuera  and  at  Tamaya  the  veins  are  characterised  by  the  presence 
of  tourmaline.  Similar  gold-copper  ores  occur  at  Remelinos  in  the 
Copiapo  department  of  the  province  of  Atacama,  where  the  country 


a  Loram,  loc.  cit.,  p.  493. 

b  Idem,  Trans.  Amer.  Inst.  M.E..  XXXV,  1905,  p.  696. 


CHILE.  659 

is  hornblende-biotite-granite  and  quartz-diorite.  Free  gold  occa- 
sionally occurs  in  the  Remelinos  veins.  The  Las  Condes  mines, 
south  of  Santiago,  are  the  highest  of  the  Chilean  mines,  lying 
at  an  altitude  above  sea-level  of  13,000  feet.  They  are  found  in  a 
granite  that  has  been  intruded  by  an.  aphanitic  andesite,a  the  ore- 
bodies  being  situated  near  the  intrusive  contacts.  Together  with 
quartz  and  tourmaline  there  occur  in  the  veins  auriferous 
copper  ores,  haematite,  anatase,  titanite,  and  zircon.  According 
to  Domeyko6  molybdenite  also  is  found.  Another  tourmaline- 
bearing  copper-gold  region  is  that  of  Peralillo,  north-west  of  Santiago, 
the  country  of  which  is  quartz-diorite.  For  northern  Chile,  there- 
fore, the  association  of  vein  tourmaline  with  auriferous  copper 
sulphides  is  on  the  whole  highly  characteristic.  Yet,  Moricke 
could  find  in  the  mines  of  Jesus  Maria,  Ojancos,  Cachiyuyo,  and 
Inca  de  Oro  (Atacama  province)  no  trace  of  tourmaline,  although 
the  veins  of  these  mines  are  in  the  same  country  (quartz-diorite) 
as  the  foregoing  tourmaline-bearing  veins.  Cachiyuyo  and  Inca  de 
Oro  mines  are  very  old  and  have  been  extensively  worked.  They 
are,  however,  rather  gold-quartz  mines  with  a  little  copper  sulphide 
than  gold-copper  mines.  In  addition  the  Cachiyuyo  vein  carries 
a  considerable  quantity  of  specular  iron  ore. 

The  general  relations  of  the  Chilean  quartz-diorites  to  the 
andesites  and  liparites  of  the  Cordilleras  are  not  very  clear,  but 
they  nevertheless  recall  very  forcibly  the  orogenic  relations  of 
the  Calif ornian  granodiorites  to  the  Nevada  andesites.  Tourmaline 
occurs  in  each  case  in  the  veins  of  the  older  rocks.  On  the  whole, 
there  is  perhaps  reasonable  ground  for  assuming  that  the  Chilean 
area  is  a  southern  analogue  of  the  Calif  ornian  province. 

The  placer  deposits  of  Chile  are  numerous  and  have  long  been 
worked  in  a  primitive  fashion,  which  is  now  gradually  giving  place 
to  modern  methods  of  sluicing  and  dredging.  The  alluvial  gold 
produced  in  Chile  in  1903  amounted  to  13,561  ounces  (421,817  kg.) 
fine  gold  worth  £57,606  (768,078  pesos). 

The  gold  of  Chilean  placers  is  fairly  coarse,  and  nuggets  of  6  and 
22  ounces  have  been  found  in  recent  years.  Many  placers,  as  at 
Loica,  Melipilla,  &c,  have  been  covered  by  clay.  The  gold  of  the 
fine  sands  of  Carelmapu  in  southern  Chile  has  been  concentrated 
on  the  ocean  beaches  until  they  sometimes  contain  as  much  as 
9  to  30  dwts.  per  cubic  yard  (10  to  35  parts  per  million).  These 
auriferous  deposits  have  been  proved  to  depths  of  26  feet.  Similar 
marine  placers  occur  at  Cucao,  and  at  Chacao  passage  near  the  island 
of  Chiloe.c 

a  Stelzner,  Zeit.  fur  prakt.  Geol.,  1897,  p.  41. 

b  "Mineralojia,"  Santiago,  1879,  p.  437. 

c  Cortes,  Bol.  Soc.  Nag.  Min.,  3,  XV,  1903,  p.  49. 


660  SOUTH    AMERICA. 

River  placers  of  some  extent  and  value  occur  at  Quilacoya, 
25  miles  north  of  Concepcion  ;  at  Marga  Marga  ;  and  at  Catapilco. 
An  attempt  was  made  to  work  the  last  in  1903  by  hydraulicing, 
but  the  enterprise  failed  from  lack  of  water.  It  is  believed  that  the 
placers  of  Loica,  Yale,  Caxuto,  and  Andacollo  would  yield  profitable 
returns  with  modern  methods. 

Ticrra  del  Fuego. — In  Tierra  del  Fuego  and  the  regions  that 
lie  adjacent  to  the  Magellan  Straits,  partly  in  Chile  and  partly  in 
Argentina,  gold  deposits  have  been  known  for  many  years.  The 
first  washings  were  made  in  the  valley  of  the  Rio  de  las  Minas, 
near  Punta  Arenas.  Towards  the  end  of  1880  gold  was  discovered 
on  the  south  coast  of  Tierra  del  Fuego,  near  Ushuaia  (Argentina), 
and  also  on  the  islands  of  Navarin  and  Lennox  (Chile).  In  1881 
one  Senor  Ponce  de  Leon  (a  name  of  happy  omen)  commenced 
gold-washing  on  the  Baquedano,  an  affluent  of  the  Rio  del 
Oro,  in  the  northern  portion  of  the  island.  Soon  after  were  discovered 
the  placers  of  the  Rio  Oscar,  which,  like  the  Rio  del  Oro,  flows 
northward  to  Magellan  Straits.  These  placers  were  worked  for 
several  years  by  individual  washers,  generally  with  profitable 
results.    In  1900  more  than  500  gold-washers  were  busily  employed. 

On  the  Rio  de  las  Minas,  near  Punta  Arenas,  attention  was  first 
directed  to  the  valley  gravels,  but  was  soon  turned  to  the  more 
accessible  older  high-level  river  terraces  when  these  were  found 
to  be  as  rich  or  richer  in  gold.  Elsewhere  on  the  mainland  south  of 
Punta  Arenas,  auriferous  alluvials  have  been  worked  in  the  Tres 
Brazos  and  Agua  Fresca  streams.  The  marine  black-sand  placers 
of  the  north  coast  of  the  Magellan  Straits  at  one  time  attracted 
considerable  attention,  perhaps  more  than  was  merited  by  their 
intrinsic  value.  The  gold  is  very  sparsely  distributed  through  the 
beach  sands,  and  the  deposits  have  in  recent  years  been  abandoned. 
Similar  marine  placers  occur  on  the  Atlantic  seaboard  of  southern 
Argentina,  immediately  north  of  Cape  Virgenes  and  of  the  eastern 
entrance  to  the  Magellan  Straits. 

On  Tierra  del  Fuego  itself  the  principal  auriferous  streams  are 
the  del  Oro,  Oscar,  Side,  Chico,  Verde,  Paravich,  Progreso,  Banco, 
«fec.  North  of  San  Sebastian  Bay  at  El  Paramo  (Argentina)  are 
marine  placers  similar  in  character  to  those  already  mentioned 
as  existing  on  the  coasts  of  the  mainland.  Many  of  the  islands 
off  the  south  coast  of  Tierra  del  Fuego  carry,  or  have  carried,  placer 
deposits  of  notable  value.  The  principal  of  these  islands  are  Nueva, 
Navarin,  Loff,  Agustin,  Picton,  Barneveld,  Lennox,  &c.  On  the 
last  mentioned  a  nugget  of  4  ounces  (124  grammes)  was  found.  A 
suction  dredge  was  erected  on  the  beach  of    this    island  in  190S; 


CHILE.  661 

and  it  was  estimated  that  1£  million  cubic  yards  of  gravel  worth 
Is.  3d.  per  yard  were  available  for  treatment.*1 

The  material  of  which  the  placer  deposits  of  Tierra  del  Fuego 
is  very  largely  composed  is  fluvio-glacial,  i.e.,  morainic  debris  that 
has  been  re-sorted  by  running  water.  Pebbles  of  mica-schist  con- 
taining auriferous  pyrite  have  been  found  near  Punta  Arenas 
and  also  on  the  island  of  Santa  Magdalena  in  the  Magellan  Straits. 
Since  similar  schists  contain  the  auriferous  veins  of  Cafiete,  Carahue, 
Valdivia,  &c,  in  southern  Chile,  it  may  be  conjectured  that  the 
alluvial  gold  of  Tierra  del  Fuego  has  been  derived  from  veins  and 
impregnations  in  such  rocks.  Fairly  large  nuggets  have  from  time 
to  time  been  found  in  Tierra  del  Fuego,  the  largest  on  record 
weighing  19  ounces  (590  grammes)  and  coming  from  the  Santa 
Maria  stream. 6  Nevertheless,  the  gold  is,  on  the  whole,  fine  and 
flaky  rather  than  coarse.  It  is  occasionally  found  crystallized 
in  distorted  octahedra  and  rhombic  dodecahedra,  and  is  often,  and 
especially  when  flaky,  coated  with  iron  oxides.  The  gold  is  from 
850  to  920  fine.  Magnetite  and  titanite  grains  are  abundant  in 
the  wash. 

In  1902  a  small  dredging  boom  took  place  in  Tierra  del 
Fuego,  and  by  the  summerof  1907-1908  no  less  than  a  dozen  dredges 
were  at  work  on  the  various  rivers  flowing  to  the  Atlantic  seaboard 
and  into  the  Magellan  Straits.  The  dredging  season  lasts  only 
for  the  summer  months — from  October  to  April  or  May, 
though  a  dredge  on  the  Rio  Oscar  is  reported  to  have  worked  all  the 
year  round  with  an  average  recovery  of  35  ounces  gold  per  week. 
A  dredge  on  the  Rio  del  Oro  is  also  stated  to  have  recovered  130 
ounces  per  week/  In  1903  there  were  produced  in  Chilean  Tierra 
del  Fuego,  4,412  ounces  (137'25  kg.)  fine  gold  worth  £18,743  ;  in 
1904,  170-182  kg.  ;    and  in  1905,  143*563  kg. 

The  relative  production  of  vein-gold  of  the  various  Chilean 
provinces  in  1903  is  shown  below  : — 


Antofagasta 

Atacama 

Coquimbo 

Aconcagua,  Valparaiso,  and  Santiago 

Talca 


Kg.  Fine  Gold.         Ounces. 


92-502  2,969 

156-105  5,011 

33-565  1.077 

42-909  1,377 

3-602  115 


a  Curie  and  Richardson,  Min.  Sci.  Press,  June  27,  1908,  p.  880. 

"  Brain,  "  Lavaderos  de  Oro  de  Tierra  del  Fuego."  Bol.  Soc.  Nac.  de  Min.,  Chile,  3, 
XVII,  1905,  p.  71  ;  Pohlmann,  Verh.  Deutsch.  Wiss.  Ver.  zu  Santiago  de  Chile,  IV, 
1900,  p.  307. 

c  Milward,  Cons.  Reps.,  1907. 


662 


SOUTH    AMERICA. 


According  to  Herrman"  the  gold  production  to  1900  has  been  : — 


Kg.  Fine 
Gold. 

Fine  Ounces. 

16th    century  (56  years) 

76,000 

2,443,400 

17th          „       

35,000 

1,125,250 

18th          

92,000 

2,957,800 

19th          

122,792 

3,947,762& 

In  the  20th  century  the  yield  has  been : 

1901             

637 

20,480 

1902             

762 

24,498 

1903             

220 

7,073 

1904             

910 

29,256 

1905             

731 

23,501 

1906             

1,427 

45,886 

Grand  total  to  end  of  1906.  . 

330,479 

10,624,906c 

a  "  La  Produccion  en  Chile  de  los  Metales  i  Minerales,  etc.,"  Santiago  de  Chile,  1903. 

^  Cortes,  however  (loci  cit.  sup.),  places  the  total  value  of  the  gold  yield  of  Chile  at 
£100,000,000,  more  than  double  the  estimate  of  Herrman. 

c  For  further  detailed  information  regarding  Chile,  the  student  may  consult :  Cortes, 
11  La  Industria  del  Oro  en  Chile,"  Santiago  de  Chile,  1890  ;  San  Roman,  "  Mineria  i 
Metallurjica  de  Chile,"  Santiago  de  Chile,  1894  ;  Yunge,  "  Estadistica  Minera  de  Chile," 
Santiago  de  Chile,  1905. 


INDEX    TO    SUBJECTS. 


.22, 


.221, 


Age  of  Placers    

Aikinite       

Alabandite,  Verespatak 

Alaskite     400,  478, 

Albite,   Vein    74,   369,    404, 

Alloys  of  Gold,  Native   

—  —  and  Palladium,  Artificial.  . . . 
Alluvial  Deposits,  Crystallized  Gold 

in  

—  Drifts      

—  Gold,  Concentration  of.. 

—  —  Fineness  of     

—  Origin  of  

—  —  India       

—  Source  of      

Amalgam,  Native      

Andesites,  Associates  of  Gold  in   . . 

—  Auriferous  Nature  of    

—  Eelation  of  Gold  to 

—  Tertiary     6, 

Andesitic  Goldfields,  Electrum  in . . 

—  —  Tellurides  in  

Antimony  Deposits,  Gold  in  ...  .144, 

Aplite,   Gold   in    101, 

Appalachian   Province    

Archaean  Group      

— ■  Schists,  Auriferous  Nature  of  . . 

—  —  India       

—  —  Western  Australia  

Arsenic,   Coromandel    

Arsenides  at  Reichenstein    

Artificial  Crystals  of  Gold   

Ascending  Solutions     

Ascension   Hypothesis    10, 

Ash,  Gold  in     

Associates  of  Gold  in  Andesites  .... 
Auric  Chloride     

—  Sulphide    

Auriferous  Aplite,  Omai    

—  Conglomerates,    Cretaceous    .... 

—  —  Permo-Carboniferous      

—  —  Witwatersrand      

—  —  South  Dakota     

—  —  Western  Australia      

—  Deposits,  Classification  of   

—  General  Relations  of 

—  —  Secondary     

-  Gravels,   Klondike    

—  Provinces      

"  Auriferous  Series,"  Hauraki         . 

—  —  Western  Australia   

Aurous  Chloride     

—  Sulphide    

Authigenic  Ores  7, 

Banket  Beds,  Natal      

—  —  Origin  of  Gold  in   57, 

—  —  Transvaal     

Barberton  Series    

"  Barrel-quartz  "     464, 

Barysphere      

Basalts,  Poverty  of  

Base-level  of  Erosion      

Beach-sands      

Bedded   Veins       

"  Benches  "     


TAGE 

94 

75 

173 

532 

652 

23 

25 

83 
88 
90 
81 
81 

261 

321 
26 
61 
77 
77 
59 
23 
61 

150 

638 
48 
47 
76 
48 
49 

309 

193 
19 

113 
45 

110 
61 
39 
37 

638 

510 

344 
95 
98 
98 
42 
1 
78 

481 
43 

307 
49 
39 
37 
10 

454 
95 

436 
50 

589 
2 
77 
87 
91 
5 
93 


PAGE 

Beresite,  Gold  in     74,  101,  202 

Bergseifen      87 

Bismuthaurite     24 

Bismuth-gold     24 

"Black  Gold"     24 

Black  Sands      90,  91,  140,  319,  342 

—  —  Garnet  in      92 

"  Blanket,"  Rico     560 

"  Blind  "  Lodes,  Waihi  317 

Bonanzas      112,  115,  124,  311 

Boiling-point  of  Gold  22 

Bullion,  Selenium  in    38 

Buluwayo  Schists  51 

Calaverite   28 

Camp  Bird  Vein     556 

Cangalli       629 

Capillary  Openings   9 

Carbonaceous  Matter,  Influence  of 

71,  79,  110 

"  Cement "      94 

Centrosphere     2 

Champion  Reef,  Kolar     253 

Characters  of  Gold    13 

Chimney     115,  116,  543 

Chloride  of  Gold     38 

Circulation  of  Underground  Water  9 

Classification  of  Auriferous  Deposits  42 

—  Ore  Deposits  4 

—  Factors    of       42 

—  Table  of     44 

Colloidal  Gold     40 

Coloradoite    34 

Composition  of  Deep-seated  Waters  79 

Compounds  of  Gold,  Natural  27 

Concentration  of  Alluvial  Gold  ....  90 

—  of   Gold      108,  111 

—  Mechanical      7 

— ■  Agent  of   7 

Conglomerates,   Archaean      95 

—  South  Dakota     : 98 

—  Western  Australia  98 

—  Witwatersrand      95 

Contact- veins    5 

Coolgardite       35 

Cordilleras  of  Australia     70 

Country-rock,    Gold    in    73 

Cretaceovis    Auriferous    Conglome- 
rates      510 

Crust  of  Earth    3 

Crystallization  of  Gold,  Zone  of  . .  80 

Crystallized  Gold 13,  15,  83,  84,  113 

Crystals  of  Gold    13 

Deep  Leads 92,  343,  373 

Deep   Mines,   Dryness   of    8 

Deep-seated     Waters,     Composition 

of      79 

Density    of    Gold    22 

Deposition  of  Gold   87,  88,  108 

Descending  Solutions   113 

Dharwar   Schists.   India    ...   48,    54,  242 

Diabase  Dykes,  Influence  of   

54,  57,  58,  59,  143 

Differentiation      7,  10 

Discission,  Spaces  of      5 

Dispersion  of  Gold    105 


664 


INDEX   TO 


PAGE 

Dissolution,   Spaces   of    j> 

Drifts.  Alluvial      °° 

Dyscrasite     • ••••     D1 

Earth.  Condition  of  Interior  of   . .  1 

Eastern  Cordilleras  of  Australia  70 

Electrum      .......... -Zl,  " 

Enriched  Sulphides,  Zone  of   . . . . . .     114 

Enrichment,   Secondary    80,     l^ 

Erosion  by  Rivers    °' 

Erythraean    Province    H' 

False   Bottoms    8j; 

Filling  of  Fissures   ••  * 

Fineness  of  Gold  ■ -Zl,  81 

Fissures,  Filling  of  5,  9>  i" 

"Float"  Gold      1Q5 

Flowage,  Zone  of      5 

Fluoride  of  Gold,  Artificial  23 

Fluorite- Gold-Tellurium  Veins 6 

Fluorite,  Cripple  Creek   6,  63,  552 

—  King's  Mountain    595 

Fracture,  Zone  of 4 

Free-gold  Ores    42,  71 

Free  Gold,  Primary    78 

—  —  Secondary      79 

Garnet  in  Black  Sands  92 

Gash  Veins    5 

Geite      „t 

Genesis  of  Sulphides    " 

Geological  Range  of  Placers   94 

Geysers,   Origin   of   8 

Glaciers,  Dispersion  by      106 

Glamm     J73 

Glauch  Veins    178 

Gneiss,  Gold  in   1°2 

Gold  Ledge,   Mercur    565 

"  Golden  Isle  "     212 

"  Golden  Mile,"  Kalgoorlie   401 

Goldschmidtite     32 

"  Gossan "      80 

Granite,  Gold  in   100 

Granodiorite  Group    67 

Graphic  Tellurium   31 

"  Green   Schists,"   Appalachians    . .  51 

Greenstone  Schists   49,  52,  388 

Ground  Water  Level    ..> 11 

Growth  of  Gold 13,  81 

"Gutter"      93 

Haematite   Magnetite   Quartz   Rock  49 

Hessite     34 

Hornblende  Schists     49,      50 

Hot  Springs,  Origin  of   8 

—  Deposits,  Gold  in  104,  519 

Igneous  Rocks,  Gold  in   100,  107 

Indicator  Minerals     61,  111 

"Indicators,"    Ballarat    ...72,   111,  364 

—  Hargraves      351 

—  Lydenburg      453 

—  Nagyag      179 

—  Panbula    358 

Infiltration  Hypothesis   95 

Interior  of  Earth,  Condition  of   . .         1 
— ■    —  Rate    of    Increase    of    Tem- 
perature               2 

Ionic  Theory     40 

Ionised    Gold    40 

'   Iron  Dyke,"  De  Lamar   518 

"  Ironstone  "     80 

Ttahiritc      649 

Jacutinga       649 

•I  urassic   Placers    94 

Kalgoorlite      35 

Kiessch  nitre       179 

Krennerite     32 

Lateral    Secretion  Theory    10,       45 

-  from   Marine   Sediments    ....  104 


TAGR 

La  Trobe  Nugget   21 

Leaf-gold     14 

Lean  Sulphides,  Zone  of   114 

"  Leather  Jacket,"   Ballarat    366 

"  Lode  Formations,"  Western  Aus- 
tralia       50 

Lollingite      151-  216 

Magmas  as  a  Source  of  Gold  100 

—  Relation  to  Gold  Deposits   76 

Magmatic  Differentiation      7 

—  Vapours      10 

—  Waters       * 

"Magpie"   Stone,   Reefton    318 

Main  Reef,  Rand    96 

Maldonite     24 

Mantos     ^57 

Marine  Placers    91 

Massive  Deposits    5 

Mercury   in   Amalgam,   Percentage 

of      26 

—  Telluride      34 

Metallogenetic  Province    47 

Metasomatic  Processes    5 

—  Replacement     10,  117 

Meteoric  Waters     7 

Meteorites,  Gold  in    102 

Monazite,   Minas   Geraes    650 

Moss-gold      I4 

Mother  Lode,  California   69,  505 

"  Muck."  Klondike     484 

Miillerine     32 

"Mustard-gold"      28 

Nagyagite     36 

Native  Alloys  of  Gold 23 

—  Gold     13 

Natural  Compounds  of  Gold   27 

Nobilite     37 

Nugget,    La   Trobe    21 

Nuggets  in  Banket  Beds,    Absence 

of     98 

—  Origin  of  81 

Nullagine  Beds,  Western  Australia  98 

Obsidian,  Gold  in  100 

Ore  Deposits,  Classification  of  4 

Ores,   Agent   of   Solution   and   Con- 
centration      7 

—  Sources  of    6,  10 

Ore  Shoots     115,179,  255 

Organic  Matter,  Influence  of   .  .110,  114 

Origin  of  Alluvial  Gold 81 

—  of  Nuggets  81 

—  of  Rand  Gold    57.  446 

—  of  Sulphides    7 

Outcrops,  Enrichment  at   80 

Oxidising  Waters   80 

Oxidised  Zone  80 

"  Pacific  Circle  of  Fire  "    59 

Palladium  Gold  25 

Pay-streaks    115 

"  Pencil-Mark,"  Ballarat  72,  365 

Permo-Carboniferous  Placers    ...94,  344 

Petzite      34 

"  Pilot-Reef,"   Panbula    358 

Placer  Deposits,  Source  of   68 

—  Hypothesis      96 

Placers    86,87,91,  94 

"  Plumbago  Floors  "  at  Gympie    .  339 

Pockets      H5 

Porpezite      25 

Pre-Cambrian  Group    54 

Precipitants  of  Gold   108 

Precipitation    of    Gold    from    Sea- 
water  106 

Primary  Form  of  Gold   78 

—  Gold-deposits     ••••■       45 

—  Source  of  Ores   10 


SUBJECTS. 


605 


PAGE 

Primary   Sulphides    78 

Properties   of  Gold   22 

Propylites     60 

Province,  Appalachian    48 

—  Auriferous     43 

—  Erythraean    47 

—  Petrological  and  Metallogenetic  47 

Pulaskite.  Boundary   479 

Pure  Gold    22 

Rand,  Origin  of  Gold  57 

Recalescence  of  Calaverite   29 

Reefs  of  Witwatersrand   441 

Refining  of  Electrum,  Natural   ....  24 
Relations    of    Auriferous  Deposits, 

General      1 

Replacement,  Metasomatic   117 

Rhodite    25 

Rhodium-gold     25 

Rocks,   Gold  in    107 

Roscoelite,   Kalgoorlie    404 

"Saddle-reefs"   ....73,  116,  349,  367,  462 

Saprolite      595 

Scorodite,  Guanaco   657 

Sea-salts,  Absence  of  Gold  from   . .  39 

Sea-water,  Gold  in  41,  104.  106 

Secondary  Deposits  78,  80,  86 

—  Enrichment     11,112,  114 

—  Sulphides      79 

—  Tellurides     79 

Sedimentary  Rocks,  Gold  in    107 

Selenide   of   Gold    38 

Selenium  in  Bullion  38,  299,  316,  530 

Shoots,  Causes  of  115 

Silicate  of  Gold  39 

Silver  Ledge,  Mercur   565 

—  Telluride      34 

Sinter  Deposits,  Gold  in   104 

Solfataric  Action  45,  60 

Solution  of   Ores    7 

Solutions,  Ascending  and  Descend- 
ing       113 

Solvent  Power  of  Liquid   9 

Solvents  of  Gold   23,  103 

Source  of  Alluvial  Gold  221,  321 

—  of   Gold    100 

—  of  Ores   6,  10 

—  Rand  Gold      446 

—  of  Underground  Waters  7 

—  of   Volcanic   Vapours    8 

Stockwork  (Stockwerk)    5 

Sudbury  Ores,  Origin  of    7 

Sulphide  Enrichment,  Zone  of   . . .  11 

—  Gold  Ores      42,  71 

—  Zone,  Secondary  Enrichment  in  11 
Sulphides,  Genesis  of  77 

—  of  Gold    37 

—  as  Precipitants   108 

—  Primary     78 

—  Secondary    79 

Sulpho-telluride      38 

—  of  Gold.  Artificial    38 

Sylvanite      29 

Table  of  Classification    44 

Talladega  Series  of  Alabama  .  51 

Tellurides  of  Andesitic  Goldfields  61 

—  Association  with  Andesites  and 

Archaean  Schists  28 


PACE 

Tellurides,   Baasick  Mine    546 

—  Black  Hills    583 

—  Bohemia     162 

—  Boulder   County    539 

—  Carolina     591 

—  Cripple  Creek    63,  550 

—  Decomposition   of    28 

—  of  Gold    23,  27 

—  Gympie     339 

— ■  Hungary      66 

—  Hinsdale  County   562 

—  Judith   Mountains    573 

—  Kalgoorlie    403 

—  King's  Mountain  595 

— ■  La  Plata  County  560 

—  of  Mercury  34 

—  Nagyag      178 

—  Offenbanya      171 

—  Ontario      471 

—  .Ores,  Occurrence  of    27 

—  Origin  of  27 

—  Precipitants  of  Gold  109 

—  Secondary        79 

—  South  Yukon  488 

—  Washington     499 

—  Zone  of  Enrichment  12,  114 

Tellurium  at  Goldfield    533 

—  Rhodesia      434 

Tertiary  Andesites    6 

—  Andesitic   Goldfields    59 

Tetradymite   in   Appalachians    ...  52 

—  at  Clogau     129 

Thio-aurates      37 

Tonalites,  Alps    119 

Tourmaline,  Berezovsk   75 

Transport  of  Gold   89,  103 

"Tundra"      493 

Twinning  of  Gold  Crystals   18 

Underground  Waters    7,  9 

Vadose  Solutions,  Gold  in    80 

—  Zone     9 

—  Chemical   Reactions   in    11 

Valencianite,   Cripple   Creek    552 

— ■  De   Lamar    519 

— ■  Idaho      516 

—  Waihi      315 

Vapours,  Magmatic   8,  10 

"  Verticals,"  Black  Hills   98,  582 

Volatilization   of   Gold    22 

Volcanic  Vapours,  Origin  of  8 

Waters,  Underground   8 

Water  Level,  Ground   11 

"  White   Channel  "    Gravels,     Klon- 
dike        483 

Wire-gold     19,  84,  624 

Witwatersrand,  Origin  of  Gold.  57,  95 

—  Series      51 

"  Zinopel  "      167 

Zircon,  Minas  Gera-es  650 

"  Zivak  "      26,  157 

Zone  of  Flowage    3 

—  of  Fracture a 

—  of  Lean  Sulphides   114 

—  of  Enriched  Sulphides    11,  114 

—  of  Enriched  Tellurides    ......12,  114 

Zones   of   Earth's   Interior    2 


GEOGRAPHICAL    INDEX. 


PAGE 

Aachen,  Germany    191 

Aar  E.,  Germany   191 

Aardal  Mine,  Norway..  195 
Aare  E.,  Switzerland  . .  152 
Abaca-an,  Philippine  Is.  291 
Abai  R.,  Abyssinia  ....  415 
Abakan  R.,  Siberia  ....  215 
Abengares,   Costa  Eica  612 

Abitibi  L..  Ontario 472 

Abra     Prow,      Philip- 
pine Is 290 

Absakowa,  Russia   ....  205 

Abu   Mt.,    India    241 

Aby     Lagoon,     French 

Ivory  Coast   419 

Abyssinia     415 

Adda  E.,  Italy  153 

Addington,  Ontario    ...  471 

Adelfors,  Sweden   197 

Adelong,  N.  S.  Wales..   343 

Adica,  Portugal   144 

Adieu-Vat,         French 

Guiana     641 

Afghanistan     227 

Afon  Mawddach  E..  N. 

Wales    124 

Afrenu,  French  Ivory 

Coast      419 

Africa    407 

Agua        Fresca        E., 

Tierra  del  Fuego  ....  660 
Agustin      Id.,      Tierra 

del    Fuego    660 

Aikaschra  E.,  Siberia..  225 
Aikawa  Mine,  Japan..   281 

Ajjampur,    India 243 

Akiti,  Egypt    408 

Akka  Tagh,  Tibet   235 

Akrizi,    French    Ivory 

Coast      419 

Alabama      51,  586 

Alakananda,   India  ...   262 
Alamo  E.,  Lower  Cali- 
fornia      599 

Alaska    491 

Alaska  -  Treadwell 

Mines,  S.E.  Alaska. .70,  496 
Alatau  Mts.,  Siberia  . .  211 
Albury,  N.S.  Wales  ..  343 
Alder  Gulch,  Montana  570 
Aleutian  Is.,  Alaska   .  . 

64,  494 
Alexandra,  Victoria    .  .   361 

Algeria    407 

Alice  E.,   Queensland..   325 

Allanda,    Spain 146 

Alle  Mi,  Italy    155 

A  lit     Ant'Fionnaraich, 

Sutherland  136 

Allt   Breacich,    Suther- 
land         136 

Allt  Duibh,  Sutherland  136 
Allt-Smeoral,       Suther- 
land      136 


PAGE 

Allt  Torrish  E.,  Suther- 
land      136 

Almeira.  Portugal  ....  143 
Aloso,      French      Ivory 

Coast    419 

Alps,  Italy   119 

Altai,  Siberia  210,  215 

Altan  E.,  Norway    ....   196 

Altar,  Mexico    600 

Altbreisach,  Germany.  190 
Altenberg,   Germany 

191,  194 

Alvega,  Portugal   143 

Alz   E-,  Germany 193 

America    57 

Amethyst,   Colorado    . .   562 

Amgun,  Siberia    224 

Amherst.  Victoria   ....  371 
Ammer  E.,  Germany..    193 
Ampasary,       Madagas- 
car       427 

Ampasimba,    Madagas- 
car      427 

Amu-darya  E.,  Siberia  212 
Amuntai,     Dutch 

Borneo  296 

Amur,    Siberia    210,222 

Amurskaia,  Siberia. . . .  222 

Anantapur,  India   259 

Anarjok  E.,  Norway  .  .   196 

Ancachs,  Peru   630 

Ancares  E.,  Spain   145 

Andacollo,  Chile    ..656,  658 

Andaray,  Peru    630 

Andel  E.,  Germany  .  .  191 
Angara   R.,    Siberia 

210,  217 

Angola     423 

Ankobra  E.,  Gold  Coast  422 
Annam,   Indo-China    .  .   285 

Annan,   Scotland    138 

Anori,  Colombia   ......   625 

Antigorio,   Italy    153 

Antioquia,  Colombia 

621,  622 

Antrona,   Italy    153 

Anvil  Creek,   Alaska...   492 

Anzasca,  Italy  153 

Apache    Canyon,    New 

Mexico    570 

Aporona.    Peru 631 

Appalachian  States  51,  586 
Approuague,         Dutch 

Guiana    642,  643 

Apurimac,   Peru    630 

Arabia    226 

Araca,  Bolivia   629 

Aranyos  E.,  Hungary..  188 
Araluen,  N.S.  Wales  .  .  346 
Ararat,  Victoria 

359.  360.  373 

Arax  E.,  Eussia    208 

Arcadia,  Greece  161 


PAGE 

Archangel,  Eussia  ....  199 
Ardeche  Dep.,  France..  148 
Ardennes  Dep.,  France  148 
Ardvorlich,  Perthshire  138 
Arenig  Mine,  N.  Wales  127 

Argentina    655 

Argesul  E.,  Eoumania..  161 
Ariege  Dep.,  France  . .   148 

Arima,  Trinidad   618 

Arizona,  United  States 

62,  536 

Arizpe,  Mexico  600 

Arltunga,  S.  Australia.  387 
Arnsberg,   Germany    .  .   191 
Arroroy,  Philippine  Is.  291 
Arrowtown,    New    Zea- 
land     320 

Aruba,      Dutch        W. 

Indies     618 

Ashburton,     W.     Aus- 
tralia     393 

Asia     210 

Asia  Minor   161,  225 

Askold  Id..  Siberia   ....  224 

Assam,    India    262 

Assikasso,  French  Ivory 

Coast     419 

Astano.  Switzerland  .  .  151 
Astorga,  Philippine  Is.  291 

Astorga,   Spain    145 

Asturias,  Spain    145 

Astyra,  Asia  Minor  .  .  226 
Atchinsk,   Siberia 

210,  214,  216 
Atlantic      City,      Wyo- 
ming      575 

Atlin   L.,   Brit.    Colum- 
bia        459,  476 

Atrato  E..  Colombia   .  .   626 

Attock,  India   262 

Attola,  Egypt   414 

Auburn,  Oregon   501 

Aude  Dep.,  France  148,  150 
Auerbach,  Germany  . .  193 
Aughatinavought      R., 

Ireland      139 

Aughrim  E.,  Ireland  .  139 
Au-hao   E.,    Manchuria  276 

Auraria,   Georgia    588 

Austria-Hungary    161 

Austrian  Silesia    162 

Australasia      305 

Australia 323 

Avoca  E.,  Victoria 

359,  360,  371,  376 

Ayan,  Siberia    225 

Baden,    Germany    190 

Bago,  French  Guinea.  .   418 
Baian-Zurga,   Siberia..   219 
Baie  Verte,  Newfound- 
land        458 

Baikal  L.,  Siberia  ....  210 
Baileyville,  Maine  ....  584 
Bailundu,  Angola   423 


668 


GEOGRAPHICAL    INDEX. 


PAGE 

Baker  Creek,  Alaska  .  .  491 
Baker's      Creek,      N.S. 

Wales     346 

Bakoy        K.,       French 

Guinea      418 

Bala.  N.  Wales   127 

Balaghat    Mine,    India  253 

Balangoda,  Ceylon 263 

Bald  Butte  Mine,  Mon- 
tana        572 

Balkash  L.,  Siberia 214 

Ballarat,    Victoria 

72,  360,  363,  376 
Ballinagore,  Ireland  . .   142 
Ballinasiloge,     Ireland  140 
Ballintempie     R.,     Ire- 
land        141 

Ballinvalley     R.,     Ire- 
land       139 

Balliscorney     Gap,    co. 

Dublin    140 

Ballycoog  Mt.,  Ireland  141 
Ballymurtagh      Mine, 

Ireland    141 

Ballythomas     R.,     Ire- 
land       141 

Baluchistan     227 

Bambuk,         French 

Guinea     416 

Banat  Mts.,  Hungary..  189 
Banco    R.,    Tierra     del 

Fuego     660 

Banmauk.  Burma   265 

Bannack,  Montana  . .  570 
Barbacoas,  Colombia..  626 
Barbara,  Hungary....  180 
Barberton,  Transvaal 

56,  438,  448 
Bardoc,  W.  Australia. .  401 

Barentu,   Eritrea    415 

Barguzinsk.  Siberia  ...  221 
Barima     Mine,     Brit. 

Guiana   637 

Barneveld    Id.,    Tierra 

del  Fuego    660 

Barossa,  S.  Australia..  385 
Barotoc   Viejo,    Philip- 
pine Is 291 

Barza,  Hungary   184 

Bassick      Mine,      Colo- 
rado      543 

Bastnas  Mine,  Sweden.  197 
Batang  Padang,  Perak  288 
Batanko,  Formosa  ....  284 
Bathurst,  N.S.  Wales..  341 

Battiggio,  Italy   154 

Batu  Bersawah,  Malay 

States     288 

Bau,  Sarawak   64,  292 

Baule,     French     Ivory 

Coast    418 

Bavaria,  Germany  ....  192 
Beaconsfield,  Tasmania 

378,  379 
Beanandrambo,    Mada- 
gascar       427 

Beboum,  French  Ivory 

■  st      419 

Bechuanaland    Protec- 
torate      '.  .   435 

Beechworth,  Victoria 

359,  361.  377 

Beja,  Portugal  144 

Bela-Beka,  Servia  . ...  159 
Bellara,  India    259 


PAGE 

Bella  Vista,  Costa  Rica  612 
Benambra,  Victoria  .  .  360 
Bendigo,    Victoria 

72.  73,  359,  360,  367 
Benguet   Prov.,   Philip- 
pine Is 290 

Beni  -  Shangal,       Abys- 
sinia      415 

Bensibetta,   India    259 

Berezovsk,    Russia 

74,  119,  199,  202 
Berners      Bay,      S.      E. 

Alaska    495 

Berringa,  Victoria  ....  360 
Berthllwyd.  N.   Wales 

125,  128,  131 
Bessieges,  France  ....  148 
Betaan  Mine,  Egypt  . .  413 
Bethanga,  Victoria  ....  361 

Bettles,  Alaska   492 

Bezimian   R,    Siberia      216 

Bhamo,  Burma     267 

Bidi,  Sarawak      64,  292 

Big  R.,  Victoria    361 

Bigaan    R.,    Philippine 

Is 291 

Big  Hurrah  R.,  Alaska  494 
Big  Salmon  R.,  Yukon..  481 
Biela       R.,       Austrian 

Silesia     

Binalud  M.U.,  Persia  . .   227 

Bingham,  Utah     563 

Birch  Creek,  Alaska  .  .  491 
Birch       Creek,       Brit. 

Columbia      476 

Birikoulski     Mine,     Si- 
beria     216 

Birrim  R.,  Gold  Coast..  422 

Bissersk,  Russia 202 

Bistrica,  Bosnia  166 

Bistrica,  Servia   157 

Bistritza  R.,  Hungary..  189 
Bistritza        R.,       Rou- 

mania    161 

Bitter-root    Mts.,    Mon- 
tana      571 

Biya  R.,  Siberia   215 

Bjorquirgts,  Sweden   .  .   197 
Black     Flag,    W.    Aus- 
tralia         401 

Black  Hills,  S.  Dakota 

52,  576 
Black    Range,  W.    Aus- 
tralia         396 

Blackwater,   New  Zea- 
land        319 

Blackwater  R.,  Suther- 
land       136 

Blackwood,  Victoria  .  .  360 
Blogodatnv  R.,  Siberia  216 
Blagojev-Kamen. 

Servia  158 
Blanco  Cape,  Oregon..  503 
Bloemhof,  Transvaal..  447 
Blue  Mts.,  Oregon.  .68,    501 

Blue  R.,  China    274 

Blue  R.,  Oregon    502 

Blue  Nile,    Abyssinia..  415 
Blue    Spur,    New    Zea- 
land        321 

Boatman's,     New     Zea- 
land        319 

Bockstein,  Salzburg  . .  164 
Bodaibo  R.,  Siberia  220,  221 
Bodenmais,  Germany..   193 


PAGE 

Bodie,  California 509 

Bodimardi,  India    259 

Bommel  Id.,  Norway  .  .  195 
Boggy  Creek,  Victoria  361 
Bogom-Darovanni 

Mine,  Siberia   216 

Bogong,  Victoria 360 

Bogoslovsk,    Russia.201,  207 

Bohemia      161 

Bohemia,  Oregon   502 

Bohmer      Wald,      Ger- 
many         193 

Boicza,    Hungary    ..66,  181 

Boj  Mts.,  Hungary 172 

Bokalik,   Tibet    229,  235 

Bokhara,  Siberia  ..210,  211 
Bolivar,    Colombia..622,  627 

Bolivia      628 

Bombay,  India 48 

Bonanza  Creek,  Yukon  485 
Bong-Miu,  Annam    ....  286 
Bonnievale,     W.     Aus- 
tralia        400 

Bontoc    Prov.,    Philip- 
pine Is 290 

Boodinnie,  India    258 

Boogardie,      W.      Aus- 
tralia        395 

Bor.  Servia   157 

Borkowitz     Mine,     Bo- 
hemia        161 

Born,  Germany   191 

Borneo    292,  294 

Borpatak,  Hungary    .     168 

Bosmishk.  Persia    227 

Bosnia     165 

Botes.  Hungary    66,  175 

Boulder  Co.,  Colorado  539 
Boulder     Creek,     Brit. 

Columbia    476 

Boulgar      Dagh      Mts., 

Asia  Minor  226 

Boundary,     Brit. 

Columbia     479 

Bound's  Cliff,  Cornwall  121 
Bourg  d'Oisans,  France  149 
Boyaca,  Colombia   ....  622 

Brad,  Hungary   66 

Braemar,  Scotland  —  138 
Brahmaputra  B.,  India 

48,  262 
Braidwood.  N.S.  Wales  343 

Bras  R.,  Quebec    468 

Bras     d'Or     L.,     Nova 

Scotia     58 

Bray   Head,   Co.   Wick- 
low      141 

Brazil     52,  644 

Breadalbane,       Perth- 
shire       138 

Breaza  Mts.,  Hungary  176 
Breckenridge,  Colorado  540 
Brewer  Mine,   S.   Caro- 
lina       58,  594 

Breznica,  Servia  157 

Brianta  R..  Siberia  .  .  222 
Bridgewater,  Vermont..  585 

Bright,  Victoria    362 

Brilon,  Germany    191 

British  Columbia  473 

British   East  Africa    .  .   425 

British  Guiana    59,  635 

British  Honduras  ....  609 
British  New  Guinea  . .  300 
British  North  America  458 


GEOGRAPHICAL    INDEX. 


669 


PAGE 

British  North  Borneo..  292 
British    Somaliland.  .  .  .   416 

British  Sudan    414 

Broad  Arrow,  W.  Aus- 
tralia         401 

Brora  L.,  Sutherland..   136 

Brusson,  Italy   155 

Bucaramanga,     Colom- 
bia      627 

Budok,  Dutch  Borneo..  295 

Bu-Khanun,  Siam  286 

Bukit      Koman      Mine, 

Malay   States   289 

Bukit    Malacca    Mine, 

Malay  States     289 

Bukit  Mas,  Perak    288 

Bukowina,  Hungary  .  .  189 
Bulgar    Ma'aden,    Asia 

Minor    161,  226 

Bull-Domingo         Mine, 

Colorado    546 

Bullfrog,  Nevada  533 

Bullion  Creek,  Utah  . .  566 
Bnlong,  W.  Australia  405 
Bulumwaal,    Victoria 

360,  361 
Buluwayo,  S.  Africa   . .     51 
Burbanks,       W.       Aus- 
tralia       400 

Burbia  E.,  Spain 145 

Bure,  French  Guinea..  417 
Buritica,    Colombia....   623 

Burma 263 

Burnt  R.,  Oregon  502 

Buroko.  Formosa  284 

Burrandong,  N.S.  AVales  344 

Burza,  Siberia   220 

Busai,        Brit.        New 

Guinea       301 

Busanshi.  Gold  Coast..  421 
Busumchi,  Gold  Coast..  422 
Buttgenbach,  Germany  191 

Byeli  Oos,  Siberia   216 

Bystra  R..  Siberia  220 

Caceres,  Colombia  ....     625 

Caceres,  Spain   148 

Cachiyuyo,  Chile  .656,  659 
Cae-gwernog,  N.  Wales  131 
Cae-mawr,  N.  Wales 

125,  131 
Calanda,  Switzerland..   152 
Calaveras  Co.,   Califor- 
nia     506 

California      68,  488,  503 

Calliope,  Queensland  .  .   337 
Camacuam,  Brazil   ....   646 
Camalmahi,  Lower  Cali- 
fornia       599 

Camarines    Norte, 

Philippine  Is.  290 
Cambrian       Mine,       N. 

Wales     125 

Cameroons,  Africa  ....  423 
Cam-Lan,  Indo-China..  285 
Camp  Bay,  Ontario  . .  471 
Campamento,  Colombia  625 
Campanha,  Brazil  .....  648 
Campaspe  R.,  Victoria  376 
Camp  Bird  Mine,  Colo- 
rado        556 

Cana,  Panama  613 

Canada      458 

Caflazas,  Panama  614 

Cani.  Italy  154 

Cania,  N.S.  Wales  ....  340 


page 
Canoona,  Queensland..  324 

Canton,  Georgia    588 

Canutillo,   Chile    658 

Canyon,  Oregon   502 

Cape  R.,  Queensland..  332 
Cape      Breton,      Nova 

Scotia     465 

Cape  Colony  456 

Capitalia  Mt.,  India  . .  241 
Capiz     Prov.,      Philip- 
pine Is 291 

Carabaya,  Peru   631 

Carcassone,  France  .  . .  150 
Carelmapu,  Chile  ....  659 
Cariboo,  Brit.  Columbia 

459,  474 
Caribou,  Nova  Scotia. .  466 

Carinthia      119,  164 

Carnon  R.,  Cornwall  . .  121 
Carrigacat  Co.,  Cork  . .  141 
Carsavene,  Dutch 

Guiana   , . . .   643 

Carupano,  Venezuela. .   633 
Casadepaga  E.,  Alaska  493 
Cascade  Mts.,  Washing- 
ton      499 

Cassel,  Germany  191 

Castell-carn-Dochan,  N. 

Wales      129,  131 

Castlemaine,     Victoria 

360,  371 
Catamarca,    Argentina  655 

Catapilco,   Chile    660 

Catena  L.,  Nova  Scotia  466 
Cauca,  Colombia 

622,  623,  624,  625 

Caucasus,  Russia  208 

Caura,  Trinidad  618 

Cavone,    Italy    154 

Cayenne      641 

Ceara,  Brazil 644 

Cebu  Id..  Philippine  Is.  291 
Cefn  Coch,  N.  Wales 

124,  127,  128,  131 
Cefn-dewddwr,  N.  Wales 

128,  130 

Cehovac.  Bosnia   166 

Ceiga,  Egypt   411,  414 

Celebes.        Dutch       E. 

Indies     296 

Central  America 597 

Cerro  de  Pasco,  Peru.  .   630 
Cerro  Prieto,  Mexipo..   600   I 
Cervenika.  Bosnia    ....   165 

Cervo  R.,  Italy 152 

Cevennes,  France  148 

Ceylon    , 263 

Chacao  Passage,  Chile..  659 
Chaffee  Co.,  Colorado..  543 
Chaka's  Kraal,  Natal. .  455 
Chakhtaminsk,  Siberia  220 
Champion  Beef,  India  253 
Chandze-toun,  Man- 
churia        275 

Cha-oo,  China   274 

Charalung,  Tibet 234 

Charcheo,    E.     Turkes- 
tan       238 

Charters    Towers, 

Queensland    71,  329 
Chaudiere,  Quebec  458,  467 
Chaungyi  Chaung,  Bur- 
ma           268 

Cheilun-tzian,         Man- 
churia       276 


PAGE 

Chentabun,  Siam   286 

Cherry  Creek,  Arizona  538 
Chestatee  E.,  Georgia..  596 
Cheticamp,        Nova 

Scotia     465 

Chiapas,  Mexico  608 

Chico    E.,    Tierra    del 

Fuego      660 

Chifumbase  Eeef,   Por- 
tuguese E.   Africa    .  .   430 
Chihuahua,  Mexico   ....  602 

Chi-li,  China  270 

Chilka,  Siberia   219 

Chiltern,  Victoria  360,  361 
Chin-chang-kou-liang, 

China      270,  271 

Chindwin  E.,  Burma  . .   267 

Chinese  Empire  270 

Chiquitos,  Bolivia   629 

Chittabalbie,  Korea  . .  277 
Chloride,  New  Mexico..  569 

Choco,  Colombia  626 

Choluteca,  Honduras..  610 
Chontales,  Nicaragua. .  611 
Choquecamata,  Bolivia  629 
Chosmalal,  Argentina..  656 
Ohota  Nagpur,  India 

55,  247,  260 
Choukpazat,  Burma  . .  264 
Chou-tsi  a-toun-pei-gu, 

Manchuria       275 

Chow-yen  Mine,  China..  271 
Christiansand,   Norway  196 

Chryse,  Burma 263 

Chuan-shan-tsze,  China  270 
Chugalak,      E.     Turke- 
stan        238 

Chukchi        Peninsula, 

Siberia       225 

Chungkeung,  Korea  ...  277 
Chuquiaguillo,  Bolivia..  629 

Cibao,  Haiti    616 

Cibuco  E.,  Haiti   617 

Cinnamon  Bippo,  Gold 

Coast    421 

Cinq    Cerf,    Newfound- 
land        458 

Clear   Creek   Co.,   Colo- 
rado        540 

Clermont,  Queensland..  325 
Clogau,    N.    Wales 

124,   128,  129 
Cloncurry,    Queensland  329 

Clone  E.,   Ireland    141 

Clough's      Gully,      N.S. 

Wales    344 

Clunes,  Victoria    360 

Cobar,  N.S.  Wales  ....  350 
Coburg,  Germany  ....  192 
Cochiti,  New  Mexico  . .  569 
Coed-cy-fair,  N.  Wales  131 
Coen,  Queensland  .....  325 
Cogotes,  Colombia   . . . .  624 

Coimhatore,  India  259 

Coimbra,  Portugal 144 

Cold  Foot,  Alaska 492 

Colombia,  S.  America 

61,  620 

Colorado   58,  62,  538 

Colossus  Mine,  N.  Caro- 
lina       594 

Columbia  E.,  Washing- 
ton         500 

Comayuga,  Honduras  ..  610 
Comstock,  Nevada  .62,  520. 


670 


GEOGRAPHICAL    INDEX. 


PACT 

Comte,  Dutch  Guiana..  643 
Oonawaruk     E.,     Brit. 

Guiana   637 

Congo  Free  State    424 

Congos  E.,  Haiti  617 

Connary  Mine,  Ireland  141 
Ooolbawn E.,  Ireland..  141 
Ooolgardie,     W.      Aus- 
tralia     399 

Copan,  Honduras   610 

Oornebruchill,      Perth- 
shire      138 

Cornwall     120 

Coromandel,   New   Zea- 
land      305,  308 

Corowa,  N.S.  Wales   . .  343 

Corozal,  Haiti   617 

Costa  Eica  612 

Costilla  Co.,  Colorado..  546 
Courcibo       E.,      Dutch 

Guiana      644 

Coutchichmg,     Appala- 
chian             51 

Coxipo-de-Ouro,  Brazil.  645 
Craddock,  Cape  Colony  456 
Craggie  E.,  Sutherland  136 
Craggiemore   Mine,   W. 

Australia 398 

Creed,  Cornwall  121 

Crawford    Moor    Mine, 

Scotland    133 

Creede,  Colorado  562 

Crescent,  Nevada 534 

Crestone,  Colorado  ....  543 
Creswick,  Victoria  ....  360 
Creuse  Dep.,  France  . .   150 
Cripple     Creek,      Colo- 
rado      63,  538,  546 

Cristales,  Colombia  . .  624 
Crista-Pucina,  Servia  157 
Crocodile,   Queensland 

325,  337 
Crocodile     E.,     Trans- 
vaal       454 

Crodo  Mine,  Italy    155 

Croghan       Kinshelagh 

Mt.,  Ireland  141 

Cronebane     Mine,    Ire- 
land     141 

Croydon,   Queensland 

71,  326 

Csertes,  Hungary  180 

Csetatye,  Hungary 172 

Cuba    615 

Cucao.  Chile   659 

Cue,  W.  Australia  ....  395 

Cuevas-Sil,  Spain 146 

Culera,    Spain    147 

Cumberland    122 

Cunapiru,  Uruguay  ....  655 
Cundinamarca,    Colom- 
bia       622 

Custer  Co.,  Colorado  .  .  543 
Cutman  E.,  Philippine 

Is 291 

Cuyaba  Mine,  Brazil  .  .  652 
Cuyuni,  Brit.  Guiana..  636 

Cuzco,  Peru    631 

Cwm  Eisen,  N.  Wales 

124,  128,  130 

Cyprus,  Greece  161 

Czebe,  Hungary    187 

1)  ibus  E.,  Abyssinia  ..  415 
Dachslander,  Germany  190 


PAGE 

Dadieso,   French   Ivory 

Coast     419 

Dagupan,      Philippine 

Is 290 

Dahlonega,    Georgia 

52,  58,  588,  589 
Dalmatchik,  Siberia  . .  219 
Dango,  French  Guinea..  418 

Dargo,  Victoria 360,  376 

Darien,  Panama 612 

Darlot  L.,  W.  Australia  396 

Darro  E.,  Spain 147 

Dart,  E.,  Victoria   ....  360 
Darwaz  Mts.,  Siberia..  213 
Davidstowe,  Cornwall..   121 
Davyhurst,      W.      Aus- 
tralia         399 

Dawson,  Yukon 482 

Day  Dawn,  Australia..  395 
Daylesford,  Victoria  . .  360 
Deadwood       City,       S. 

Dakota     576 

Debach,  Egypt  413 

Dee  E.,  Scotland   138 

De  Kaap,  Transvaal  . .  448 
De  Lamar,  Idaho  ..64,  516 
Deli-Jovan,  Servia  157,  158 
Denuki  Bay,  Celebes  . .   298 

Deraheib,  Egypt   413 

Descubidoro  Mine, 

Mexico    602 

Deshneff  Cape,  Siberia..  225 

Devon     121 

Dharwar  Eeefs,  India..  257 

Dhoni  E..  India   256 

Diahot    E.,    New    Cale- 
donia         302 

Dialu    Ambrului    Mts., 

Hungary 171 

Dialu  Wunet  Mts.,  Hun- 
gary        171 

Didesa  E.,  Abyssinia  . .  415 
Diemel  E.,  Germany  . .  191 
Dieu-Merci,       French 

Guiana    643 

Dihong  E.,  Tibet  237 

Dioula,  French  Guinea  418 
Disputed   Territory,    S. 

America    59,  642 

Djalinda,  Siberia 222 

Djelilovac,  Bosnia  ....   166 
Dobbs    Linn    E.,    Scot- 
land        138 

Dodder  E.,  Ireland  . .  140 
Dojdlivoi,  Siberia  ....  223 
Dolgelly.  N.  Wales  ....  127 

Doliana,  Greece   161 

Dolomi,  S.E.  Alaska  . .  495 
Dolores  Co.,  Colorado. .  560 
Dolores  Mine,  Mexico.  .  604 
Dol-y-frwynog,  N.  Wales 

124,  128,  130 
Dombagammana,    Cey- 
lon       263 

Dominion  of  Canada  .  .  458 
Dominion  Creek,  Yukon  482 
Dom  Pedrito,  Brazil  . .  646 
Donau  E.,  Germany  . .  193 
Donnybrook,  Queens- 
land        332 

Donnybrook,    W.    Aus- 
tralia         406 

Dorea-balta  E.,  Italy..   153 

Dorsch.  Siberia  212 

Dos   Estrellas,   Mexico..  605 


PAGE 

Douglas   Id.,   Alaska 

70,  495 

Drau  E.,  Hungary   189 

Drauthal,  Carinthia  . .  164 
Drave  E.,  Hungary  . .  189 
Drumlummon,  Montana 

571,  572 
Ducktown,   Tennessee..  596 

Dudswell,  Quebec    469 

Duerna  E.,   Spain    145 

Duivel's  Kantoor,  Trans- 
vaal       453 

Dumisa,  Natal  455 

Dumludagh  Mts.,   Asia 

Minor      226 

Dundas,  W.  Australia. .  406 
Dunolly,    Victoria.  .360,  371 

Durango,  Mexico  604 

Durness,   Scotland    133 

Dusseldorf,  Germany..  191 

Dutch    Borneo 294 

Dutch  East  Indies  294 

Dutch  Guiana  59,  639 

Dutch  West  Indies  618 

Dzungaria      Ala-Tagh, 
E.  Turkestan  ........  238 

Eagle  Valley,  Nevada..  534 
East  Cape,  Siberia  ....  225 

East     Coolgardie,      W. 

Australia      401 

East    Indian    Archipe- 
lago         64,  290 

East  Mnrchison,  W.  Aus- 
tralia         396 

Eastern        Cordillera, 

Australia      323 

Eastern  Turkestan  ....  237 
Ecbatana,    Persia     ....   227 
Echandia  Mine,  Colom- 
bia     625 

Echunga,    S.    Australia  383 

Ecuador    61,  627 

Edea    Station,     Came- 

roons       423 

Eder  E.,  Germany   191 

Edjudina,  W.  Australia  399 

Egypt     57,  408 

Eibenstock,  Germany..  193 
Eidsvold,  Queensland..  340 
Eidsvold  Mine,  Norway  195 

Eikyu,  Japan  281 

El  Alamo,  Lower  Cali- 
fornia        599 

El  Callao,  Venezuela 

59,  633 
El     Clavo     Eico,    Hon- 
duras        610 

El  Coco.  Colombia 624 

Eldorado    Canyon,   Ne- 
vada       535 

Eldorado  Creek,  Yukon 

483,  485 

Elga  E.,  Portugal   143 

Elizabethtown,       New 

Mexico    568 

Elk  City,  Idaho    515 

Elkhorn,  Montana  574 

Ellefeld,  Germany   193 

El  Ora,  Mexico 597,  605 

El  Paraiso,  Honduras..  610 
El  Paramo,  Argentina..  660 
El    Porvenir,    Salvador  609 

El  Tigre,  Mexico  600 

Elvan  E.,  Scotland 138 

Elvo  E.,  Italy   152 


GEOGRAPHICAL   INDEX. 


671 


PAGE 

Elwund  Mt.,  Persia  . .  227 
Elysee,  French  Guiana  643 

El   Yunque,   Haiti    617 

El        Zancudo       Mine, 

Colombia     623 

Emin  Pasha  Gulf,  Ger- 
man E.  Africa 425 

Emmen  E.,  Switzerland  152 
Enachimo  E.,  Siberia..  218 
Encampment,  Wyoming  575 
Engelsberg,     Austrian 

Silesia    162 

England     120 

Enoch's  Point,  Victoria  361 

Eria    E.,    Spain    145 

Eridia,  Egypt  412,  414 

Erieux  E.,  France   148 

Eritrea,  Africa 415 

Erricht  E.,  Inverness..  139 
Erzebirge,   Germany   . .  193 

Escambrax,  Spain 148 

Eshowe,  Natal  455 

Esmeraldas,  Ecuador..  628 

Esperanza,  Mexico  605 

Espritu  Santo,  Panama 

62,  613 
Essequibo      E.,      Brit. 

Guiana    637 

Etheridge,    Queensland 

71,  328 
Eucalyptus,     W.     Aus- 
tralia        399 

Eule-Jilova    Mine,    Bo- 
hemia       161 

Eungella,  Queensland . .  333 

Eureka,  Nevada   535 

Europe   119 

Evancon  Mine,  Italy  . .  155 

Evora,  Portugal    144 

Faczebaj,  Hungary  —  176 
Faczebanya,  Hungary..     66 

Fairbanks,  Alaska 492 

Fairhaven,  Alaska  ....  493 
Fairview,  Nevada  ....  525 
Faleme       E.,       French 

Guinea       416 

Falkenstein,  Germany..  193 
Falun  Mine,  Sweden  . .  197 
Famine  E.,  Quebec  ....  468 
Fanantara,  Madagascar  427 

Far  Daod,   Persia    227 

Fatira.  Egypt  413 

Federated  Malay  States  287 
Feher    Koros   R.,   Hun- 
gary      188 

Felsberg,  Germany  ....  191 
Felsobanya,  Hungary 

66,  168 
Felso-Kajanel,  Hungary  182 

Ferguson,  Nevada  534 

Fericsel,  Hungary  ..66,  176 
Ferry     Co.,    Washing- 
ton       500 

Fianarantsoa,      Mada- 
gascar    427 

Fichtelgebirge,      Ger- 
many      192 

Fife,  Scotland     133 

Finland     198 

Finmark,  Norway    ....   196 

Finnallaz,  Italy     155 

Fish  R..  N.S.  Wales    . .  341 

Fiji 303 

Flattery     Cape,    Wash- 
ington      500 


PAGE 

Florence,  Arizona    537 

Florence,  Idaho  515 

Fleiss  R.,  Carinthia   . .   165 

Foix,  France  148 

Fojnica  R.,  Bosnia  ....  165 

Fo-Kien,  China 274 

Forest  of  Dean,  Glou- 
cester      122 

Formosa  64,  283 

Foro,  Portugal  144 

Fort       Steele,      Brit. 

Columbia     477 

Fortymile  R.,  Alaska 

481,  491 

Foster  Victoria 360 

Fowakhir,  Egypt 413 

France     148 

Frankenberg.  Germany  191 
Fraser  R.,  Brit.  Colum- 
bia      475 

Freiwaldau,     Austrian 

Silesia    162 

Fremont,    Wyoming    . .  575 

French   Congo    423 

French  Guiana.. 59,  416,  641 
French  Indo-China  ....  285 
French  Ivory  Coast  . .  418 
Freuchie  L.,  Perthshire  138 
Friar's  Moor,  Scotland.  133 
Fritglar,  Germany  ....  191 
Frontenac,  Ontario  . .  471 
Frontino  Mine,  Colom- 
bia         623 

Fu  R..  China 273 

Fujita,  Formosa  284 

Fuko  Hills,  Formosa  .  .  284 
Fulda  R.,  Germany  . .  191 
Fungurume,  Congo  Free 

State   424 

Funter       Bay,       S.E. 

Alaska    495 

Fusch  Thai,  Salzburg..  164 
Futa-Jallon,       French 

Guinea     418 

Fuzesd  R.,  Hungary  . .  180 
Fyedorovski  R.,  Siberia  216 
Gabriel's     Gully,     New 

Zealand     321 

Gadag,  India  .  .241,  244,  256 
Gaffney's     Creek,     Vic- 
toria      361 

Galarino,      New     Cale- 
donia     , 303 

Galas  R.,  Malay  States  288 

Galugo,  Persia 227 

Ganllwyd,  N.  Wales 

125,  128,  131 
Gard  Dep.,  France  . .  148 
Garonne  Dep.,  France  148 
Garth-Gell      Mine,      N. 

Wales   125 

Gascoyne,  W.  Australia  394 
Gastein  Thai,  Salzburg  164 
Gay's  R.,  Nova  Scotia  465 
Gebel  Aswad,  Egypt  . .  411 
Geispolsheim,  Germany  190 
Geiswasser,  Germany..  190 
Geltuga  R.,   Siberia    . .  220 

Genii   R.,   Spain    147 

Georgia 51,  586 

German  East  Africa  . .  425 
German  New  Guinea  . .  302 
German     South     West 

Africa    455 

Germany     190 


PAGE 

Gibara,       Brit.      New 

Guinea    300 

Gibbonsville,  Idaho   ...  515 

Gilan,  Formosa  284 

Gilbert  R.,  Quebec  ....  467 
Gilpin  Co.,  Colorado   . .  540 

Gilyui  R.,  Siberia    222 

Gindusa,  Servla  157 

Gippsland,  Victoria. ...  361 
Gira     R.,     Brit.     New 

Guinea      301 

Giran,   Formosa    283 

Giron,  Colombia   627 

Givors,  France  148 

Glasbach,  Germany ....  192 
Glasdir,  N.  Wales 

125,  128,  131 
Glenalmond,  Perthshire  138 
Glendun  R.,  Co.  Antrim  140 
Glengaber  R.,  Scotland  138 
Glengonnar,  Scotland 

133,  138 
Glen    Lednoch,    Perth- 
shire       138 

Glen     Quaich,     Perth- 
shire        138 

Glenturret,    Perthshire  138 

Gloucester   122 

Glynn's        Lydenburg 
Mine,  Transvaal   ....  453 

Gmiind,  Carinthea 164 

Goltzsch  R.,  Germany..  193 

Goritz,  Germany 192 

Goitref,  N.  Wales 131 

Golconda,  Tasmania  . .  378 
Goldbach,    Germany 

191,  192 
Goldberg.  Germany ....   193 
Goldberg-Haynau,   Ger- 
many     193 

Gold  Bluff,  California. .  514 
Goldbottom  Creek, 

Yukon  486 

Gold   Coast    420 

Gold  Creek,  Alaska 493 

Golden       Chersonese, 

Burma    263 

Golden  Isle,  Siberia  . .  212 
Goldenville,  Newfound- 
land    458 

Goldenville,         Nova 

Scotia      461,  463 

Goldfield,  Nevada  64,  530 
Goldhausen,  Germany  191 
Gold    Hill,    Nevada    ..  522 

Gold  Hill,  Utah    566 

Goldisthal,  Germany  . .   192 
Goldkronach  Mine,  Ger- 
many     192 

Gold-mine  R.,   Ireland   140 
Goldscope,  Cumberland  122 
Goldville,   Appalachia..    51 
Golubinje     Mts„    Hun- 
gary      188 

Golungo  Alto,  Angola..  423 
Gondo,  Switzerland  ....  151 
Gongo     Socco,     Brazil 

649,  653 
Gorbilok  R.,  Siberia 

217,  218 
Gordon-bush         Burn, 

Sutherland     136 

Gork,  Tibet   235 

Gornj-Vakuv.  Bosnia..  166 
Gorontalo,   Celebes    ...  298 


672 


GEOGRAPHICAL    INDEX. 


PAGE 

Gosselin  R..  Quebec  468 
Gosseline  R.,  Haiti  616 

Gotcha  L.,  Russia  ....  208 
Goulburn  R.,  Victoria..  376 
Gou-teia-pao-tsi  L.,  Man- 

churia    275 

G  iwkamma,        Cape 

Colony    456 

as,  Eonduras  . ...  610 
Grafton,  New  Mexico  .  569 
Granada,  Spain  .  ...145,  147 
Crane!.'       Ronde       R., 

Oregon       502 

Grandola.  Portugal     ..  144 
Grass      Valley,      Cali- 
fornia        508 

Grassy      Gully,      N.S. 

Wales    357 

Great  Barrier  Id.,  New 

Zealand    317 

Great       Chingan       R., 

Manchuria 276 

Great  Falls,  Maryland  585 
Great  Fingall  Mine,  W. 

Australia     395 

Great  Pit  R.,  Siberia.  217 
Great       Mourozhnaia, 

Siberia    218 

Greece       161 

Orenfell,  N.S.  Wales     .   343 
Grevstones,    Co.    Wick- 
low       140 

Grisons    Canton,    Swit- 
zerland      152 

Groete      Creek,      Brit. 

Guiana    636 

Grouse  R.,  Brit.  Colum- 
bia       474 

Guadalupe     y      Calvo, 

Mexico     603 

Guanaco,  Chile  656 

Guanajuato,  Mexico  . .  607 
Guaracabulla,  Cuba   .     615 

Guatemala       608 

Gute-Gottes  Mine,  Ger- 
many         192 

Guinibattan  R.,  Philip- 
pine Is 291 

Gulgong,  N.S.  Wales  . .  343 
Gumeracha,     S.     Aus- 
tralia      ■  ■  385 

Gumesh-Khana,       Asia 

Minor     226 

Gundagai,  N.S.  Wales..  343 
Gunjee  Thok,  Tibet...  234 
Gunnison  Co.,  Colorado  554 
unntershausen,       Ger- 
many        191 

(iutthal    Mine,    Carin- 

thia     165 

Gwyn-fynydd,  N.  Wales 

128,  129 
Gympie,  Queensland 

70,  71,  325,  337 
Haddabanatta,  India..  259 
Haenertsburg,     Trans- 
vaal        448 

Hahndorf,  S.Australia  385 
Haile     Mine,    S.    Caro- 
lina     57,  592 

Bailey,   Idaho    515 

Baimur,    Egypt     414 

Haiti 615 

Bamadan,  Persia  ....  227 
Bamesh,    Egypt    413 


PAGE 

Hamilton,    Queensland  325 
Bammond  Id.,  Queens- 
land       325 

Handa  Mine,  Japan   . .  280 
Hardanger  Fjord,  Nor- 
way       196   i 

Hargraves,  N.  S.  Wales  351   | 
Harqua     Halla      Mts., 

Arizona     537 

Harrietville,   Victoria 

360,  361,  362 
Bartley,  N.  S.  Wales..  341 
Barz  Mts.,  Germany  .  192 
Hashidate  Mine,  Japan  280 
Hastings,  Ontario  ...  471 
Hatlefjelddalen,  Nor- 
way        195 

Hauraki,  New  Zealand 

64,  305,  306,  308 
Hazara,  Afghanistan..  228 
Heathcote,  Victoria  .  .  360 
Heidelberg,    Transvaal 

438,  447 
Heilungchiang,       Man- 
churia       276 

Heinzenberg  Mine, 

Tyrol      163 

Helaw,  Burma   267 

Heldovi,   Bosnia    166 

Helmlingen,     Germany  190 
Helmsdale    R.,    Suther- 
land        136 

Henze  Basin,  Burma..  269 
Herault  Dep.,  France.  .  148 
Hermosillo,  Mexico  .  .  602 
Hidaka  Prov.,  Japan..   279 

Hidalgo,  Mexico    605 

Hill  End,  N.  S.  Wales 

346,  350 
Hillgrove,  N.  S.  Wales  346 
Hillsboro',  New  Mexico  569 
Hinsdale  Co.,  Colorado  562 
Hirschberg,     Germany  193 

Hispaniola   615 

Hkamti-Long,    Burma..  269 

Ho  Mine,  Japan   280 

Hodgkinson.       Queens- 
land       326,  337 

Hodritsch,  Hungary    . .   168 
Hohenberg    Mts.,    Aus- 
trian Silesia   162 

Hokkaido,    Japan    ....   279 

Holguin,  Cuba   615 

Homestake,   S.  Dakota 

52,  98,  576 
Homtini,    Cape    Colony  456 

Hondo,  Japan    279 

Hondol,   Hungary    ....   180 

Honduras     609 

Honshu,  Japan       279 

Hontani,   Japan    281 

Hoppeke  R.,  Germany  191 
Horn  Id.,  Queensland  325 
Hoshino  Mine,  Japan..   282 

Hosur  Reef,  India   257 

Houang-tsao-pa,  China  274 
Hpyengan-To,  Korea. .  277 
Hukong  Valley,  Burma  269 

Hungary      65,  167 

Hunker  Creek,  Yukon  486 
Hussab,    German    S.W. 

Africa     455 

Hutti,   India  ...  .49,   55, 

239,  244,  257 
Ibague,  Colombia  ....  626 
Iburi  Prov.,  Japan...   279 


PAGE 

Ichimba  R.,  Siberia  . .  218 
Idaho,  United  States..  515 
Idaultit,  Morocco  ....  407 
Ikoma,       German       E. 

Africa     426 

Ikuno  Mine,  Japan...  281 
Hi  R.,  E.  Turkestan  . .  238 

Ilia,   Siberia    220 

111  R.,  Germany    190 

Illon,   Guatemala     ....   608 

Hz  R.,  Germany    192 

Imani  R.,  Siberia  ....  224 
Inambari  R..  Bolivia  628 
Inca  de  Oro,  Chile.  .656,  659 

Inde,  Mexico  604 

Indenie,   French   Ivory 

Coast      418 

India      48,  54,  238 

Indo-China,   French    . .   285 

Indus  R.,  India    262 

Inglewood,  Victoria    . .  360 

Inn  R.,  Germany 193 

Innai  Mine,  Japan.  ..  280 
Insuzi  Valley,  Natal..  454 
Invercauld,  Scotland..  138 
Iola  Mine,  N.  Carolina  595 
Iponan    R.,    Philippine 

Is 291 

Iramba,      German      E. 

Africa     425 

Irawadi  R.,  Burma. . . .  266 

Ireland      139 

Irtish  R.,  Siberia 214 

Iser  R.,  Germany  ....  193 
Isere  Dep.,  France  ....  149 
Ishikari  Prov.,  Japan  279 
Istalif,    Afghanistan  . .   228 

Istein,  Germany   190 

Itabira  Mine,  Brazil  . .  654 
Italian   Somaliland. . . .  416 

Italy    152 

Ivalojoki  R.,  Finland..  199 
Ivanitzki  Mine,  Siberia  216 
Ivanovski,  Siberia  ....  221 

Ivdel  R.,  Russia   207 

Jackson  Co.,  Oregon  . .  502 

Jaina  R.,  Haiti 616 

Jamaica    618 

Jambusan,  Sarawak  . .  292 
Jamieson,   Victoria     . .   361 

Japan    64,  278 

Java,  N.E.  Rhodesia  . .  430 
Jazonof  Klad,  Siberia  223 
Jebel       Jasus       Mine, 

Egypt     413 

Jena,   Germany     192 

Jericho,    Victoria 361 

Jesjok  R.,  Norway  ....  196 
Jesus  Maria,  Chile...  656 
Joannovski,  Siberia  . .  216 
Johanngeorgenstadt, 

Germany      193 

John  Day  R.,  Oregon.  .  502 
Joliba        R.,        French 

Guinea       467 

Josephine  Co.,  Oregon  502 
Judith  Mts.,  Montana  572 
Juil  R.,  Roumania. ...  161 
Jujuy,  Argentina  ....  655 
Juneau,  Alaska. ..  .493,  496 
Jupiter  Creek,  S.  Aus- 
tralia       385 

Jyekundo,  Tibet   236 

Kaap  R.,  Transvaal    .  .  454 
Kaapsche   Hop,   Trans- 
vaal        453. 


GEOGRAPHICAL    INDEX. 


673 


PAGE 

Kabin,  Siaru   286 

Kabligatti,    India    257 

Kafveltberg,  Sweden..  197 
Kago  Mine,  Japan  ....  282 
Kahajan      R.,      Dutch 

Borneo       295 

Kai-ja,   China    273 

Kaiser  Wilhelm's  Land  302 
Kajanel     Mine,     Hun- 
gary       183 

Kalami  R.,  Siberia 218 

Kalgoorlie,      W.      Aus- 
tralia     50,  388,  401 

Kalmoru,  Korea  277 

Kalu-ganga  R.,  Ceylon  263 
Kamanan,      French 

Guinea   417 

Kambara,    French 

Guinea       418 

Kambove,    Congo    Free 

State   424 

Kamchatka,  Siberia  . .  225 
Kamen  Mine,  Siberia..  221 
Kamenka  R.,  Russia..  206 

Kamerun,   Africa   423 

Kamyschak,  Russia    . .   204 
Kanagase  Mine,  Japan  281 
Kanahira  Mine,  Japan  280 
Kandahar,      Afghanis- 
tan          227 

Kangaroo   Id.,    S.   Aus- 
tralia        385 

Kangwondo,  Korea  . .  277 
Kaniamapoo,  Brit. 

Guiana      637 

Kanowna,  W.  Australia 

50,  389,  405 
Kapanga,  New  Zealand  308 
Kapdup  R.,  Burma...  269 
Kapnik,  Hungary  ....  66 
Kapnikbanya,  Hun- 
gary       168 

Kapuas       R.,       Dutch 

Borneo    295 

Kara  R.,   Siberia 220 

Karacs,   Hungary    ....   187 
Karacs-Czebe,  Hungary  187 
Karakash,    E.    Turkes- 
tan        237 

Karangahake,  New 

Zealand     312 

Karasjok,  Norway  ....   196 
Karatagh,    E.    Turkes- 
tan       238 

Karavkum,    Brit.    New 

Guinea   301 

Kasai,  Angola   423 

Kasei  Mine.  Japan....  281 
Kasejovic,  Bohemia  . .  162 
Kasejowitz,  Bohemia. .  162 
Kassinga,  Angola  ....  423 
Katanga,    Congo    Free 

State    424 

Katzbach     Mts.,      Ger- 
many        194 

Kauffung,  Germany  . .  194 
Kawarau       R.,       New 

Zealand     320 

Kawend,   Persia    227 

Kazakova,  Siberia  ....  220 
Kechau,  Malay  States  289 
Keewatin,  Appalachia  52 
Kef-um-Tabul,    Algeria  407 

Kehl,  Germany     190 

Kelantan,  Malay  States  288 
Kelung  R.,  Formosa  . .  283 


PAGE 

Kemi  R.,   Finland    198 

Keneiba,    French 

Guinea      417 

Kenwyn,  Cornwall  121 

Kerbi    R..   Siberia    224 

Keswick,     Cumberland  122 
Ketahoen      Mine,      Su- 
matra        299 

Ketchikan,  S.E.  Alaska 

494,  495 
Keveri,        Brit.        New 

Guinea     301 

Khakidian  Mts.,  French 

Guinea     416 

Khamaungthwe  R., 

Burma    269 

Khangarok,  Siberia  . .  219 
Khapka  L.,  Siberia  . .  224 
Khotan,  E.  Turkestan  237 
Kiandra,  N.  S.  Wales..  345 

Kiating,  China      273 

Kildonan     R.,     Suther- 
land      135,  136 

Kilkivan,    N.   S.   Wales  340 
Kilo,  Congo  Free  State  424 
Kimberley,      W.      Aus- 
tralia        391 

Kim-Son,    Annam    ....   285 
Kinbrace     R  ,     Suther- 
land        136 

Kin-cha-kiang  R., 

China  274 

Kin-kiang,   China  274 

Kingower,    Victoria    . .  371 
King's    Bluff,    S.    Aus- 
tralia         385 

King's  Mt.,  N.  Carolina 

52,  594 
Kinkwaseki  Mine,  For- 
mosa      284 

Kint,  Italy      154 

Kirnik  Mts.,  Hungary  172 
Kisalmas-Porkura, 

Hungary  181 
Kitami  Prov.,  Japan..  279 

Kiushiu,    Janan    282 

Kizil-Su  R.,  Siberia    . .   211 
Klamoth  R.,  California  510 
Kleinkems,   Germany..  190 
Klein    Letaba,    Trans- 
vaal        448 

Klerksdorp,   Transvaal 

438,  447 
Klingnau,  Switzerland_152 
Kloben  Mine,  Carinthia"165 
Klondike  R..  Yukon   . .  482 

Klondyke,   Alaska   459 

Kluchi  Mine,  Siberia..  219 
Klungau  R.,  Siberia  . .  214 
Knysna,  Cape  Colony..  456 
Kobuk  R.,  Alaska  ....  492 
Kormoczbanya,  Hun- 
gary      167,  168 

Korosbanya,  Hungary  187 
Koffikouro,  French 

Ivory  Coast  419 

Kohistan,  Afghanistan  228 

Kokah,  Tibet      230 

Kokchietav,  Siberia  . .  211 
Kokombo  Mine,  French 

Ivory   Coast    419 

Kokomo,  Colorado   ....  541 

Koko  Nor,  Tibet  235 

Kolab,  Siberia   213 

Kolar,  India    49,55,239,  249 


PAGE 

Kollegal,    India    259 

Komata,  New  Zealand  317 
Komati.  Transvaal    ....  450 

Komuro,   Japan    282 

Kondom  R.,  Siberia  . .  215 
Kongarok  R.,  Alaska..  493 
Kongsberg,  Norway  . .  195 
Konstantinovsky, 

Siberia  222 
Kopa,    E.    Turkestan  .  .   238 

Kopa,  Tibet     235 

Kopparberg.  Sweden  . .   197 
Koptekorskoi,  Russia..  201 
Korabia,   Hungary    ....  175 
Koranda      Mts.,      Hun- 
gary        186 

Kordofan,   Brit.   Sudan  414 

Korea     276 

Kosen  Mine,  Japan  .  .  280 
Koskokwim  R.,  Alaska  494 

Kosseir,  Egypt  413 

Kotaboenan,  Celebes  . .  298 
Kotchkar,  Russia 

74,  119,  206 
Kotchkara  R.,  Russia..  206 
Kourou,  Dutch  Guiana  643 
Koyukuk  R..  Alaska  . .  492 
Kragga     Poort,      Cape 

Colony     457 

Krasnoiarsk,  Siberia 

210,  216 
Kremnitz,  Hungary 

66,   167,  168 

Kresevo,  Bosnia    166 

Kreuzberg,  Germany  .  .   192 

Krian,  Sarawak    292 

Krivelj,    Servia     157 

Kromdraai,    Transvaal  450 

Krutoi,    Siberia     222 

Kuala  Kangsar,  Perak  288 
Kuaotunu,     New     Zea- 
land      312,  317 

Kuba,  Russia    209 

Kucajna,  Servia  .157,  158 
Kuen-Lun  Mts.,  Tibet. .  228 
Kugman  R.,  Philippine 

Is 291 

Kuk  San  Dong,  Korea  277 
Kulamadau,  Brit.  New 

Guinea       300 

Kumusi   R.,   Brit.   New 

Guinea       301 

Kunanalling,    W.    Aus- 
tralia         399 

Kundor,  Malay  States  288 
Kunene  R.,   Angola    . .   423 

Kur   R.,    Russia    208 

Kuratani  Mine,  Japan..  280 

Kurile   Is 64 

Kurnalpi.       W.       Aus- 
tralia       405 

Kusan,  Dutch  Borneo..  295 

Kushirnsk.  Russia    202 

Kuznetzoff      Mine,      Si- 
beria         217 

Kyobin,   Burma    268 

Kyoukpazat,    Burma 

64,  264 
Kyshtimsk,    Russia    ...204 
Kyu-fun       Mts.,       For- 
mosa         283 

Kyusnu,  Id.,  Japan  . .  282 
La    Belliere    par    Mon- 

trevault,  France   ....   150 
Labi,  French  Guinea..  418 


674 


GEOGRAPHICAL   INDEX 


PAGE 

La  Caunette,  France  . .  148 
La  Cienaga,  Mexico  . .  600 
La  Cumbre,  Mexico  . .  603 
Ladock.  Cornwall  ....  121 
La  Espanola,  Haiti  . .  616 
La  Gardette,  France  . .  149 
La  Higuera.  Chile  656,  658 
Laio-tie-chan,  Man- 
churia          275 

Lakany,  Hungary  ....  189 
Lake    of    the    Woods, 

Ontario     52,  58,  471 

La  Libertad,  Nicaragua  611 
La  Lucette,  France  .  .  150 
La  Luz,   Mexico    .......  608 

Lambton,  Quebec    469 

Lanang  E.,   Philippine 

Is 291 

Lanarkshire        134 

La  Nava  de  Jadraque, 

Spain      148 

Lancefield      Mine,      W. 

Australia      398 

Landak  R.,  Dutch  Bor- 
neo      295 

Lane  Co.,  Oregon  ....  502 
Lang      Cleuch      Head, 

Scotland    133 

Langleuch     R.,      Scot- 
land       138 

Lapland,  Finnish    198 

La  Plata  Co.,  Colorado  560 

La  Pol,   Spain   146 

Laposbanya,    Hungary  168 

La  Poza,  Salvador 609 

Larder  L.,  Canada  470,  472 
La    Roche-de-Glun, 

France  148 
La  Salada,  Colombia.  623 
Las  Condes.  Chile.. 656,  659 
Las  Hurdes,  Spain  ....  148 
La  Sierra  da  Caviera, 

Portugal    144 

Las  Quebradas,  Guate- 
mala      608 

Last      Chance      Creek, 

Yukon     486 

Lasva   R.,    Bosnia    165 

Lata  R.,   Russia    202 

Laurium  Mine,  Greece  161 
Lauscha  R.,  Germany  192 
Lauwigewank,        New 

Brunswick    467 

Lavant  Thai,  Carinthia  164 

La  Vega,  Haiti 616 

Laverton,  W.  Australia  397 

La  Voulte.  France 148 

Lawa,  Dutch  Guiana 

639,  643 
Lawlers.   W.   Australia  396 

Lead,  S.  Dakota   578 

Leadburn  R.,  Scotland  138 
Leadhills,  Lanarkshire 

133,  134,  138 
Leadville,  Colorado    ...  541 
Lebong      Soelit,      Su- 
matra        299 

Le  Chatel?*.  France  . .   150 
Leeds,  Quebec    .........  469 

Lefroy,  Tasmania.  .378,  381 

Legyin.  Burma  265 

Leiksaw.  Burma   268 

Lena,  Siberia  ....210,220 
Lengholz.  Carinthia    . .   164 


PAGE 

Lennox  Id.,  Tierra  del 

Fuego     660 

Leon,    Spain    145 

Leonora,  W.  Australia  397 
Leonovski,  Siberia  ....  223 
Lepanto   Prov.,   Philip- 
pine   Is 290 

Lewes  R.,  Yukon  481 

Lezard  R.,  Dutch 

Guiana  644 
Liard,  Brit.  Columbia..  477 
Liau-tung      Peninsula, 

Manchuria      274 

Liberia     418 

Liberty  Bell,  Colorado  559 
Liegnitz,  Germany  . .  193 
Lieser  Thai,  Carinthia  164 
Lightning  Creek,   Brit. 

Columbia      474 

Ligneuville,  Germany..  191 
Likolai-Pavdinsk, 

Russia  202 
Lilloet,  Brit.  Columbia  477 
Lincoln  Co.,  Nevada  . .   534 

Lisle,   Tasmania    378 

Lithang,  Tibet  236 

Little   Belt   Mts.,   Mon- 
tana           574 

Little      Bendigo,      Vic- 
toria           364 

Little   Mourozknai'a, 

Siberia  218 
Little  South-west  Mira- 
michi  R.,  New  Bruns- 
wick       467 

Llanlivery.  Cornwall  .  .  121 
Lluvia    de    Oro    Mine, 

Mexico    603 

Lobva   R.,   Russia    ....   202 
Lochearnhead,     Perth- 
shire       138 

Loddon  R.,  Victoria  . .  376 
Lowenberg,    Germany 

193,  194 
Loff    Id.,     Tierra    del 

Fuego   660 

Loica,   Chile    659 

Loiza  R.,  Haiti  617 

Lomagundi,      S.      Rho- 
desia       432 

Long  Ditton  R.,  Quebec  469 
Long  Tunnel,  Victoria  361 
Loon  Kiang  R.,  China..  274 
Los  Sauces,  Chile  ....  656 
Lossva  R.,  Russia  ....  201 
Lower  California  .  .68,  599 
Lowhee  R.,  Brit. 

Columbia  474 
Lucknow,  N.S.   Wales 

70,  351 
Lungau    Tauern,    Salz- 
burg           163 

Limy,    Cornwall    ......   121 

Luquillo  R.,  Haiti   617 

Luzon    Id.,    Philippine 

Is 290 

Lydenburg,  Transvaal 

57,   438,  450 
Lyell,  New  Zealand   . .  319 
Lyman,     New      Hamp- 
shire      584 

Lyndhurst,   N.S.   Wales  353 

Lyra,    Ireland    142 

Macetown,     New     Zea- 
land       320 


PAGE 

Mclvor,  Victoria  359 

McKee.      Creek,     Brit. 

Columbia      476 

Mac-Mac,  Transvaal   . .  453 
McNamee    Gulch,    Ore- 
gon      502 

Madagascar     426 

Madam     Berry     Lead, 

Victoria     376 

Madrizen,  Eritrea  ....  415 
Magdalena,  Colombia 

622,  625 
Magdalena,  Mexico   ....  600 

Magellan  Straits  660 

Magog  R.,  Quebec   ....  469 

Magura,  Hungary    180 

Maha,    China 273 

Maibong,   Korea    277 

Maiden,  Montana    572 

Mai-duc,  Indo-China  . .  285 
Mai-Leng,  Annam  ....  285 
Maine.  United  States..  584 
Maine    et    Loire    Dep., 

France      150 

Mainit,  Philippine  Is.  292 
Majama    R.,     German 

New  Guinea    302 

Majdanpek,  Servia  ....   157 

Ma-Kang,   China   274 

Ma-ku,   China    274 

Mala,    Hungary     180 

Malaga,  Nova  Scotia..  466 

Malay  States    287 

Maldon,  Victoria  ..360,  371 
Malheur  R.,  Oregon  . .  502 
Maliy-Khigan,  Siberia..  222 
Mallina     Diggings,    W. 

Australia      393 

Malmani,  Transvaal...  450 
Malmedy.  Germany  ...  191 
Malomalski.  Siberia  . .  220 

Malone  R.,  Italy  152 

Mambare  R.,  Brit.  New 

Guinea      301 

Mambulao    Mine, 

Philippine  Is.  290 

Mameyes  R.,  Haiti  617 

Manasarowar  L.,  Tibet  232 

Manati    R.,    Haiti    617 

Manchuria       274 

Mandor,  Dutch  Borneo  295 
Manghine,    New    Cale- 
donia        302 

Mangoro,  Madagascar  427 
Manhattan,  Nevada  . .  526 
Manhattan     Id.,     New 

York       585 

Manica,   Portuguese  E. 

Africa    429 

Manicaland,        Portu- 
guese E.  Africa 430 

Manizales.  Colombia  . .  622 
Mannahill,      S.      Aus- 
tralia        385 

Mannock     Moor,    Scot- 
land        133 

Mano,  N.E.  Rhodesia..  430 
Manor  Water,  Scotland  138 
Mantraim,   Gold   Coast  421 

Mantua,   Cuba 615 

Manwyne,  China  274 

Maquine,   Brazil    .  .649,  654 

Maranhao,  Brazil    644 

Marapona.  Ceylon   263 


GEOGRAPHICAL    INDEX. 


675 


PAGE 

Marble    Bar,    W.    Aus- 
tralia         393 

Marga  Marga,  Chile  . .  660 
Mariinsk,  Siberia  ....  214 
Marikuppam,  India  .  .  249 
Maritime  Prov.,  Siberia 

210,  223 
Marlborough         Prov., 

New  Zealand 318 

Marmato,  Colombia  .  .  624 
Marmora,  Ontario  ....  472 
Maroni  R.,  Dutch 

Guiana  643 
Maros  R.,  Hungary  . .  188 
Marowyn      R.,      Dutch 

Guiana      639,  643 

Martigne-Ferchaud, 

France  150 
Marudu   Bay,   Brit.   N. 

Borneo      292 

Maryborough,  Victoria 

360,  370 
Maryland,    United 

States      585,  586 

Marysvale,  Utah 566 

Marysville,    Montana..  571 
Masbate      Id.,     Philip- 
pine Is 291 

Mashonaland    435 

Massawippi  R.,  Quebec  469 

Matabeleland     435 

Mathinna,  Tasmania 

378,  381 
Matlock,  Victoria  ....  361 
Matsuoka  Mine,  Japan  279 
Matto  Grosso,  Brazil..  644 
Maunabo  R.,  Haiti....  617 

Mavilla   R.,   Haiti    617 

Mawddach  R.,  N.  Wales 

128,  131 
Mayenne  Dep.,  France  150 
Mayola  R.,  Ireland  . .  139 
Mayumba,    French 

Congo  423 
Mazar-Su  R.,  Siberia..  211 
Mazaruni       R.,       Brit. 

Guiana     636 

Meggat  R.,  Scotland  . .  138 
Meiningen,   Germany..   192 

Melipilla,  Chile     659 

Melmoth,   Natal    454 

Membris,    Spain    147 

Menival,  Spain     146 

Menzies,   W.   Australia  398 

Mercur,   Utah    563 

Merionethshire,  N. 

Wales  124 
Mesta     Kara     Su     R., 

Turkey     160 

Metovonica,  Servia  . .  157 
Meurthe-et-Moselle 

Dep.,  France  148 

Mexico     597,  605 

Miask,   Russia    204 

Miandrivago,        Mada- 
gascar      427 

Michipicoten,  Ontario  471 
Middle  R.,  Nova  Scotia  465 
Miglieglia,  Switzerland  151 

Mill   R.,   Quebec    468 

Miller  Creek,  Yukon  . .  486 
Millwood,  Cape  Colony  456 
Milne   Bay,   Brit.   New- 
Guinea     301 

Mina  Chivato,  Chile   . .   656 


page    | 
Minas   Geraes,  Brazil 

52,  646,  651 
Minas   Prietas,   Mexico  602 
Mindanao    Id.,    Philip- 
pine Is 291,  292 

Mineral  Co.,  Colorado  562 
Minho  Prov.,  Portugal  144 
Minnesota,    United 

States  584 
Minusinsk,  Siberia 

214,  216 
Miola  R.,  Ireland  ....  139 
Miramar,  Costa  Rica..  612 
Misamis,  Philippine  Is.  291 
Miaima    Id.,   Brit.   New 

Guinea     301 

Missale,  N.E.  Rhodesia  430 
Mitcheldean,  Gloucester  123   i 
Mitchell's    Creek,    N.  S. 

Wales     356 

Mitta  Mitta  R.,  E.  Aus- 
tralia          70 

Mlava  Valley,  Servia..  156 
Mo-che   Mine,   Manchu- 
ria      276 

Moll  R.,  Carinthia 164 

Moel    Offryn    Mine,    N. 

Wales     125 

Moera      Supongi,      Su- 
matra        300 

Moffat  Water,  Scotland  138 
Mogollon      Mts.,      New 

Mexico    569 

Moldava  R.,  Hungary. .  189 
Mole-chaung,  Burma  . .  267 
Moliagul,  Victoria  ....  371 
Molyneux       R.,       New 

Zealand     320 

Monateigue     Mt.,     Ire- 
land        141 

Monfortinho,  Portugal  144 
Montagu,   Nova  Scotia  466 

Montana    69,  570 

Mont    d'Or,    New   Cale- 
donia    302 

Monte  Beglio,   Switzer- 
land    151 

Monte  Cristo,  Washing- 
ton       62,  499 

Monte     del     Aguacate, 

Costa  Rica  612 

Monte  Loreto,  Italy   . .  155 
Montenau,  Germany  . .   191 
Montes  Claros,  Peru  . .  630 
Moodie's  Range,  Trans- 
vaal        450 

Moon  Plain,  Ceylon    . .  263 

Morocco,  Africa    407 

Morope      R.,      German 

New   Guinea    302 

Morro      Santa      Anna, 

Brazil    53,  650 

Morro  Velho,  Brazil  53,  651 
Mother    Lode,    Califor- 
nia     505,  506 

Mount  Baker,  Washing- 
ton     499 

Mount  Biggenden,  N.  S. 

Wales    340 

Mount  Bopple,  Queens- 
land       327 

Mount     Boppy,     N.    S. 

Wales 349 

Mount  Britton,  Queens- 
land    337 


PAGE 

Mount    Brown,    N.    S. 

Wales  342,  343 

Mount  Drysdale   Mine, 

N.  S.  Wales 350 

Mount  Lyell,  Tasmania 

378,  383 
Mount  Magnet,  W.  Aus- 
tralia     395 

Mount      Malcolm,      W. 

Australia      397 

Mount     Margaret,     W. 

Australia      397 

Mount  Morgan 70,     71 

Mount  Morgan,  Queens- 
land      324,  333 

Mount      Morgan,       W. 

Australia    397 

Mount    Nebo,    Queens- 
land        333 

Mount      Pleasant,      S. 

Australia      385 

Mount  Shamrock, 

Queensland  337 
Mount  Sir  Samuel,  W. 

Australia      396 

Mount    Uniacke,    Nova 

Scotia     466 

Mouralia,  French 

Guinea  416 
Mourzhnaia  R.,  Siberia  217 
Mozar  Su  R.,  Siberia..  213 
Mozit   Chaung,   Burma  266 

Mras  R.,  Siberia  215 

Mssalala,     German    E. 

Africa     425 

Muanza,      German     E. 

Africa     425 

Muhlgrun,  Germany  . .  193 
Miiller      Mts.,      Dutch 

Borneo    296 

Mulline,   W.    Australia  399 
Mulwarrie,      W.      Aus- 
tralia       399 

Munnak  Thok,  Tibet..  235 
Mur  Thai,  Salzburg   . .  163 
Murchison,  Transvaal..  448 
Murchison,      W.      Aus- 
tralia        394 

Murray  R.,  Victoria  . .  376 
Murua   Id.,    Brit.    New 

Guinea   . .' 300 

Murzinski,  Siberia 223 

Muszari  Mine,  Hungary  183 

Muwaylah,  Arabia 226 

Myitkyina,  Burma  ....  266 

Mylau,  Germany  193 

Myothit,  Burma   267 

Myrtleford,  Victoria  . .  360 
Mysore,  India  ..48,  243,  253 

Nabapur,   India    256 

Nacoochee,   Georgia    . .  589 

Nagyag,  Hungary   66 

Nagyalmas,  Hungary. .   176 

Nagyar,  Hungary    177 

Nagybana.Hungary  66,  168 
Nairn  R.,  Inverness   . .   139 
Nakety   R.,    New    Cale- 
donia       303 

Nakhoda,  Siberia     224 

Nalon,  Burma   267 

Namaqualand,  S.Africa  51 
Nambsheim,  Germany  190 
Nam-Hsawm  R.,  Burma  269 
Nam  Kwan  R.,  Burma  269 


676 


GEOGRAPHICAL   INDEX. 


PAGE 

Namma.  Burma   269 

Nanjangud,  India 244 

Nan  nine,  W.  Australia  395 
Nantanen  Mine,  Sweden  197 
Natal,  S.  Africa  ...  .51,  454 

Navalgas,  Spain  146 

Navarin  Id.,  Tierra  del 

Fuego     660 

Na  Zlatnici,  Bohemia. .  162 
Nechi  R.,  Colombia    . .  625 
Negri  Sembilan,  Malay- 
States     288 

Negros  R.,  Haiti  617 

Nelson,  Brit,  Columbia  480 
Nelson       Prov.,       New 

Zealand     318 

Nenthorn,  New  Zealand  320 
Nerchinsk,  Siberia  210,  218 
Nerchinsky-Zavod, 

Siberia  220 

Nestus  R.,  Turkey   160 

Neualbenreuth,        Ger- 
many      193 

Neuquen,  Argentina  . .  656 
Nevada,  United  States 

62,  520 
Nevada  City, California  508 
Neviansk,  Russia     ....   202 

New   Brunswick    467 

New  Caledonia 302 

New    England,     N.     S. 

Wales     346 

Newfoundland    458 

New  Guinea    300 

New  Hampshire,  United 

States     584 

New  Klondike,  German 

E.  Africa  425 

New    Loch    Fyne,    Vic- 
toria      361 

New     Mexico,     United 

States    62,  567 

New  South  Wales  ..71,  341 

New  York  State   585 

New  Zealand  . . .  .53,  64,  305 
Nguru,       German       E. 

Africa     426 

Nhat-Son,  Indo-China. .  285 
Niagalla,  French 

Guinea  417 
Niagara,  W.  Australia  398 

Nicaragua    611 

Nicholas,   Siberia    213 

Nieva  R.,  Russia 202 

Nieves,   Spain     146 

Niffer,  Germany   190 

Niper  R.,  French 

Guinea  417 

Nijni,   Siberia    221 

Nijni-Tagilsk,  Russia..  202 
Nikito-Ivdel,  Russia    . .  201 

Nilav.    R.,   Siberia    224 

Nillinghoo,  S.  Australia  385 

Niman  R.,  Siberia  223 

Nimelien    R.,   Siberia..   224 

Niriella,   Ceylon    263 

Nithsdale,   Scotland    . .  133 

Nkandhla,    Natal     454 

Nopal    R.,    Italian    So- 

maliland   416 

Nome,   Alaska    492 

Nondweni,   Natal 454 

Norboten,  Sweden  ....  197 
Normanby,  Queensland  333 


PAGE 

Norseman,   W.   Austra- 
lia        406 

North  America    ...62,  458 
North  Bloomfield,  Cali- 
fornia      513 

North  Carolina.  .51,  57,  586 
North    Coolgardie,    W. 

Australia      398 

North  East  Coolgardie, 

W.  Australia    405 

NorthEastern  Rhodesia  430 
Northern  Shan  States, 

Burma    268 

Northern  Territory,  S. 

Australia      386 

North    Lachlan,    N.    S. 

Wales     343 

North  Molton,  Devon..  122 

North  Wales  124 

North  Yenisei,   Siberia  210 

Norway      195 

Novaggio,    Switzerland  151 

Nova  Scotia  58,  461 

Novo-Troitzk,  Siberia..  220 
Nueva   Id.,    Tierra    del 

Fuego     660 

Nueva     Ecija,     Philip- 
pine Is 290 

Nueva    Segovia,    Nica- 
ragua        611 

Nukha,  Russia  209 

Nullagine,      W.       Aus- 
tralia     56,     98 

Nundydroog  Mine, 

India  253 
Nyassaland         Protec- 
torate         426 

Obi-Sanghi-Khergov, 

Siberia  213 

Ocampo,  Mexico    604 

Oelberg  Mts.,  Austrian 

Silesia    162 

Oembilien,  Sumatra  . .  300 
Offenbanya,  Hungary 

66,  171 
Offin  R.,  Gold  Coast   .  .   422 

Oglio  R.,  Italy  153 

Ogofau,  Wales   123 

Ojancos,  Chile   656 

Ojo  Caliente,  New 

Mexico  569 
Okhotsk   Sea,   Siberia 

210,  225 

Okhotyek,  Siberia   225 

Okuzu   Mine,  Japan    .  .   280 
Olah  Laposbanya,  Hun- 
gary       168 

Olancho,  Honduras...   609 

Olary,  S.  Australia 385 

Oldham,  Nova  Scotia. .   466 

Oldoi  R.,  Siberia 222 

Olekma.    Siberia    ..211,  220 

Olenetz,   Russia     199 

Oloviannoia,  Siberia  . .  219 

Olten,  Switzerland 152 

Oltul  R.,  Roumania. ...  161 

Olve,   Norway     196 

Omai,  Brit.  Guiana. ...  636 

Omeo,  Victoria     361 

Omori  Mine,  Japan  . .  281 
Om  Nabardi,  Egypt  . .  414 
Oneib  Mine.  Egypt  ....   413 

Onon,  Siberia 219,  220 

Ontario     58,  470 


PAGE 

Ooregaum,  India 249 

Ooregum  Mine,  India..   253 

Oos  R.,  Siberia 215 

Oppa       R.,       Austrian 

Silesia    163 

Oquirrh  Mts.,  Utah    . .  565 

Orbo  R.,  Italy   153 

Oreo  R..  Italy    152 

Oregon      68,  501 

Orel  L.,   Siberia    224 

Orenburg,  Russia 75 

Orke  R.,  Germany  ....  191 
Orlofka   R.,   Siberia    .  .   221 

Oro-Fino,  Odaho   515 

Oroville,  California    ...  513 

Orphani,  Turkey  160 

Orsk,  Russia   207 

Ortiz  Mts.,  New  Mexico  568 
Oshima  Prov.,  Japan..  279 
Osseika  R.,  Russia  ....  206 

Otaca,   Peru    630 

Otago,  New  Zealand 

53,  306,  319 
Otava  R.,  Bohemia  . .  162 
Otyikango,  German 

S.W.  Africa  455 
Oued-el-Dzeheb,  Algeria  407 
Ouray  Co.,  Colorado  .  .  554 
Ouro  Preto,  Brazil  649,  650 
Ouspensky,  Russia  ....  206 
Outeniqua    Mts.,    Cape 

Colony     456 

Oveido,  Spain    145 

Overs,  Nova  Scotia...  466 
Ovens  R.,  Victoria  361,  376 
Ovoca  Valley,  Ireland..  141 
Owyhee  Co.,  Idaho  ....  515 

Oxus  R.,  Siberia   212 

Oyapok,  Dutch  Guiana  643 
Pachuca,  Mexico     ..62,    605 
Pactolus  R,,  Asia  Minor  225 
Paddington,    W.     Aus- 
tralia        401 

Pagoeat,  Celebes  297 

Pahang,  Malay  States  289 
Pahardiah,  India  ....  261 
Pajawa     R.,      German 

New   Guinea    302 

Palacios-Sil,  Spain  ....   146 

Palehleh.  Celebes   297 

Pallo  Letok.  Tibet   235 

Palmer,   Queensland 

326,  337 
Palomas,  Mexico      ....   600 
Pamba,       N.E.       Rho- 
desia        430 

Pambujan,    Philippine 

Is 291 

Pamiers.  France  148 

Pamplona,    Colombia..   627 

Panama     612,  622 

Panbula,  N.S.  Wales  . .  358 
Pandan     Mts.,     Dutch 

Borneo      295 

Pan.i  R.,  Afghanistan..   228 

Pan.i  R.,  Siberia  212 

Parii,  Brazil    644 

Paracale  Mine,   Philip- 
pine   Is 290 

Paracatu,  Brazil  654 

Paramos-Sil,  Spain  ....   146 

Parana,  Brazil 644 

Paranao,  Chile 656 

Paravich  R.,  Tierra  del 
Fuego     66ft 


GEOGRAPHICAL   INDEX. 


677 


PAGE 

Park  City,  Utah  ..563,  566 
Parkerville,   Oregon    . .   502 

Parral,  Mexico    603 

Parry  Sound,  Ontario..  471 
Paaoh,  Malay  States  . .  288 
Passagem,  Brazil  ..53,  650 
Pas-Trop-T6t,     French 

Guiana      643 

Pataz,   Peru    632 

Patia  E.,   Colombia    . .   626 

Patom  B.,  Siberia   220 

Peak,   N.S.   Wales    ....  344 
Peak     Downs,    Queens- 
land      325,  340 

Peak     Hill,     W.     Aus- 
tralia     50,  389,  394 

Peavy,  Alaska   .... 492 

Peichan,   Japan    279 

Pei-lien-tsa,  Manchuria  275 

Pek  Valley,  Servia 156 

Pellawatta-Ganga 

Plain,  Ceylon  263 

Pellucias,  Brazil   650 

Pelly  E.,  Yukon    481 

Penaflor,  Spain   148 

Penchanga  E.,  Siberia 

217,  218 
Pendinnie,      W.      Aus- 
tralia         399 

Penhalonga     Mine,    S. 

Ehodesia 433 

Penrhos,  X.  Wales   ....   131 
Pepita   de   Oro,    Salva- 
dor      609 

Perak,  Malav  States  . .  288 
Peralillo,  Chile  ....656,  659 

Persia    227 

Perthshire    138 

Peru       61,  630 

Peschiera,  Italy    154 

Peshastin,       Washing- 
ton         498 

Pestarena,  Italy    154 

Petchanka.  Eussia 207 

Petchora  B.,  Eussia  . .  199 
Peterborough,  Ontario  471 
Peters  Mine,  Brit, 

Guiana  59,  638 
Petersburg,  Germany..  192 
Petersdorf ,  Germany  .  .  193 
Petropavlovsk,    Eussia  201 

Philippine  Is 64,  290 

Phillips    E.,     W.     Aus- 
tralia       406 

Phillipsburg,  New 

Mexico  569 
Phillipsburgh,     Mon- 
tana      572 

Philp  E.,  Queensland..  325 
Picton    Id.,    Tierra    del 

Fuego   660 

Piczegus,  Hungary    ....  180 

Pierce,  Idaho   515 

Pietersburg,  Transvaal 

438,  447 
Pigg's  Peak.  Transvaal  454 
Pigholugan,  Philippine 

Is 291 

Pike's  Peak,  Colorado..  538 
Pilbara,    W.    Australia 

55,  98,  388,  392 
Pilgrim's    Eest,   Trans- 
vaal       450 

Pine  Creek,  Brit. 

Columbia  476 


PAGE 

Pine    Creek,     S.     Aus- 
tralia        386 

P'ing-tu,  China 271 

Pinogo,  Celebes  298 

Pinos  Altos,   New 

Mexico  569,  604 
Pinutan,  Philippine  Is.  291 

Pioche,  Nevada  534 

Piracicaba  E,  Brazil..   645 

Pitfield,   Victoria 376 

Placer,    Philippine    Is.  292 
Plagwitz.    Germany    . .   193 
Pleasant     Creek,     Vic- 
toria           359 

Plomo,  Colorado   546 

Plymouth,   Vermont    . .   585 

Po  E.,  Italy    152 

Poconota,  Bolivia  ....  630 
Podkamennaia-Tungu- 

ska  E.,  Siberia  .210,  217 
Podvintzeff,  Siberia  . .  216 
Pojana      Euska     Mts., 

Hungary    188 

Poliakowski  Mts., 

Eussia  204 

Polynesia     290 

Pongola,  Natal  454 

Pontddu.  N.  Wales 129 

Popoff  Id.,  Alaska  ....  494 
Porce  E.,  Colombia  . .  625 
Porcupine     Creek, 

Alaska  493 
Porkura,  Hungary  ....   176 
Port       Adams,      Man- 
churia       275 

Port      Arthur,      Man- 
churia      275 

Portage  Id.,  Quebec  . .  470 
Port   Ayan,    Siberia    . .  225 

Porto,   Portugal    144 

Port  Orford,  Oregon  . .  503 

Portugal      143 

Portuguese  East  Africa  429 
Portuguese  Nyassaland  430 
Poseidon,  Victoria   ....  373 
Possession  Id.,  Queens- 
land        325 

Potomac  E.,  Maryland  585 
Pouembout,  New  Cale- 
donia      303 

Powder  E..  Oregon....   502 

Pozer  E.,  Quebec 468 

Prescott.  Arizona  ....  537 
Preservation  Inlet,  Newr 

Zealand     320 

Prestea,  Gold  Coast  . .  422 
Pretoria,  Transvaal  . .  450 
Primorskoi,  Siberia  210,  223 
Prince     Albert,    Cape 

Colony     456 

Prince    of    Wales    Id., 

Queensland    325 

Prince  of  Wales  Mine, 

N.  Wales  125 

Prinz  Apulca, 

Nicaragua  611 
Progreso  E.,  Tierra  del 

Fuego     660 

Prokopeiovski,    Siberia  221 

Prome,  Burma  266 

Prussia.  Germany  ....  194 
Puerto  Principe,  Cuba  615 
Puerto  Eico,  Haiti  ....  616 
Pumpsant,  Wales  ....  123 
Punjom,  Malay  States  289 
Puno,  Peru   631 


PAGE 

Punta    Arenas,    Tierra 

del  Fuego  660 

Puruni,   Brit.   Guiana 

636,  638 
Pychminsk,  Eussia  ....  203 
Pyshma  R.,  Eussia....   199 

Qua  E.,  Spain    145 

Quan-che    Mine,    Man- 
churia      276 

Quan-in-chan  Mine, 

Manchuria  276 

Quebec       467 

Quedrada  de  Esmorca, 

Bolivia       630 

Queen's   E.,    Transvaal  454 

Queensland     71,  324 

Queyras      Mine,     New 

Caledonia     303 

Qualicoya,  Chile   660 

Quinua   Mine,    Peru    .  .   631 
Quiuna    Mine,     Colom- 
bia          623 

Eadjang-Lebong, 

Sumatra  64,  298 

Eaigara,  India 261 

Eainy  L.,  Minnesota 

52,  584 

Eainy  E.,  Ontario   471 

Eajong  E.,  Tibet 235 

Eammelsberg, 

Germany  192 
Eampart,  Alaska  ....  491 
Eamu       E.,       German 

New  Guinea  302 

Eand,  S.  Africa 56 

Eanibennur,  India  ....  243 
Eapasos,  Brazil   ...  .53,  652 
Eappahanock    E.,    Vir- 
ginia     586,  587 

Earico   E.,    Portuguese 

E.  Africa 430 

Rathhaus  Mine, 

Carinthia  165 
Eat  Portage,  Ontario..  471 
Eaub,  Malay  States   . .  289 

Eaucourt,  France  149 

Eauris  Mine, 

Carinthia  165 
Eauris   Thai,   Salzburg  164 
Eavenswood,      Queens- 
land   ". 71,  325,  332 

Eavno,  Siberia   212,  213 

Eawhide,  Nevada  ....  526 
Eeal  del  Castillo, 

Lower  California  599 

Eecht,  Germany   191 

Eed  Hill,  W    Australia  405 

Red  Mt„  Colorado  557 

Eed  E.,  New  Mexico..  569 
Eeedy  Creek,  Victoria..  360 
Behne  E.,  Germany  . .  191 
Eeichenstein,  Germany  193 
Eeicher     Frost     Mine, 

Germany       193 

Eeichmannsdorf,      Ger- 
many      192 

Eeisengebirge, 

Germany  193 
Eemedios,  Colombia  . .  623 
Eemelinos,  Chile  .  .656,  659 
Eenfrew,  Nova  Scotia..  466 
Eeuss  E.,  Switzerland..  152 
Eevelstoke,  Brit. 

Columbia  480 
Eevue    E.,    Portuguese 
E.  Africa   429 


678 


GEOGRAPHICAL   INDEX. 


PAGE 

Rewa   R..  Fiji    303 

Rheinau.  Germany....  190 
Rheinweiler,  Germany  190 
Rhine  R.,  Germany  ..  190 
Rhine  R.,  Switzerland..  152 
Rhinebeek,  New  York..  585 
Rhodesia,  S.  Africa 

51,  430 
Rhone  R.,  France  ....  148 
Rhyolite.  Nevada  ..64,533 
Ribierao      do      Carmo, 

Brazil     645 

Ribnaia,  Siberia  ..217,  218 
Richmond       R.,       N.S. 

Wales     342 

Rico,  Colorado   560 

Ridang,  Servia 157 

Rio         Cagayan        R., 

Philippine  Is 291 

Rio  das  Nortes,  Brazil  645 
Rio  de  la  Paz,  Bolivia  629 
Rio      de      las      Minas, 

Tierra  del  Fuego ....   660 
Rio     del     Oro,     Tierra 

del  Fuego     660 

Rio     Grande     do     Sul, 

Brazil      644,  646 

Rio  Inambari.  Peru  . .  632 
Rio  Nusimiscato,  Peru  632 
Rio    Oscar,    Tierra   del 

Fuego     660 

Rio  San  Juan   do  Oro, 

Bolivia     630 

Rion  R.,  Russia   208 

Riviere     des     Plantes, 

Quebec      468 

Riviere  du  Loup, 

Quebec  468 
Rockley,  N.S.  Wales  . .  343 
Rocky  R„  N.S.  Wales  343 
Rodewisch,  Germany  . .   193 

Rogitz,    Germany    192 

Ronningshausen,      Ger- 
many         191 

Rosa   Mt.,    Switzerland    151 
Rosario      Mine,      Hon- 
duras         610 

Rose      Blanche,      New- 
foundland        458 

Rosedale,  New  Mexico..  569 

Rosita,   Colorado 543 

Rosmaninhal,  Portugal  143 
Rossland,  Brit. 

Columbia  477,  478 

Rostigah,  Ireland 142 

Rotenzechau,  Germany  193 
Roudny  Mt.,  Bohemia.  .  161 

Roumania    161 

Rozhdestvensky, 

Siberia  224 

Ruda,  nungary    183 

Ruhleville,    Annam....   286 

Runk.    Hungary    180 

Rushworth,  Victoria  .  .   360 

Russia    198 

Rutherglen,  Victoria 

360,  361 
Ruwe,  Congo  Free 

State  424 

Saal  R.,  Germany   192 

Sachsen-Weimar, 

Germany  192 
Sacramento     R„     Cali- 
fornia        513 

Sadiola,  French  Guinea  417 


PAGE 

Sado  Id.,  Japan   281 

Safaga,  Egypt    413 

Safet-darya,  Siberia  . .  214 
Sagri-datch,  Siberia.  .  .  .  214 

Saiga.  Egypt   411,  414 

St.    Aignan    Id.,    Brit. 

New  Guinea    301 

St.  Anne  Mines,  Servia  158  | 
St.  Ann's,  Trinidad  . .  618  : 
St.  Arnaud,  Victoria 

360,  371 
St.  Austell  Moor,  Corn- 
wall      121 

St.  Barbe,  Servia   158 

St.  David's,  N.  Wales..  127 
St.  Elie,  Frencb  Guiana  643 
St.  Francis  R.,  Quebec  469 
St.  Stephen, New  Bruns- 
wick        467 

St.  Teath,  Cornwall  . .  121 
Sakaleona,  Madagascar  427 
Salientinos,  Spain  ....  146 
Salmon  R.,  Nova  Scotia 

463,  466 

Salta,  Argentina 655 

Salvador    • 609 

Salween  R.,  Burma. ...  269 
Salzacb  R.,  Germany..   193 

Salzburg    163 

Sambas       R.,       Dutch 

Borneo    295 

Samson  R.,  Quebec...   468 
Sanarka  R.,  Russia    . .  206 
San  Borja,  Lower  Cali- 
fornia        599 

Sandhurst,  Victoria   . .  367 

Sandia,  Peru  631,  632 

San     Enrique,     Philip- 
pine Is 291 

San  German,  Haiti j>17 

Sangli  Mine,  India...  256 
Sangre  de  Cristo  Mts., 

Colorado    546 

San  Juan,  Argentina..   655 
San  Juan  Co.,  Colorado  561 
San  Juan  Mts.. Colorado  561 
San    Juan    Mts.,    Hon- 
duras      610 

San  Juan  R.,  California  513 
San     Juan     del     Oro, 

Bolivia  629 

San  Luis,  Argentina  . .   655 
San  Luis  Potosi,  Mexico  607 
San    Miguel    Co.,    Colo- 
rado        558 

San  Nicholas,  Colombia  624 
San  Pedro,  Mexico  ....  607 
San  Pedro,  New  Mexico  570 
San    Pedro    Mts,    New 

Mexico    568 

San  Sebastian,  Salvador  609 
Santa-Barbara,       Hon- 
duras        610 

Santa      Clara,      Lower 

California    599 

Santa  Cruz,  Honduras  610 
Santa  Isabel,  Colombia  624 
Santa  Maria  R.,  Tierra 

del  Fuego     661 

Santander,  Colombia 

622,  627 
San-tao  R.,  Manchuria  276 
Santarem,  Portugal   . .   143 
Santo    Domingo,    Nica- 
ragua       611,  615 

Santo  Domingo,  Peru.  .   631 


PAGE 

Sao  Bento  Mine,  Brazil  653 
Sao  Gonzalo,  Brazil  . .  648 
Silo  Gregorio,  Uruguay  655 
Sao   Paulo,  Brazil   ....   644 

Sao  Sepe,  Brazil   646 

Saranu,    French    Ivory 

Coast      419 

Sarawak,   Borneo 292 

Sargidi,      German      E. 

Africa     426 

Sarka  Shya,  Tibet  235 

Satyamangalam,  India  259 
Sauk,  Washington  ....  499 

Savinac,    Servia    157 

Saxony,  Germany  ....  193 
Schalkau,  Germany  . .  192 
Schellgaden,  Salzburg..  163 
Schemnitz,  Hungary 

66,  167,  168 
Schmiedeberg,  Germany  193 
Schwarza  R.,  Germany  192 
Schwarzburg,  Germany  192 
Schwarzen-brunn,  Ger- 
many         192 

Schwarzwasser,       Ger- 
many         193 

Sciummegale,     Eritrea  415 

Scotland    133 

Searchlight,  Nevada  . .  534 
Sebakwe,  S.Rhodesia..  433 
Seiglitz-Pockhart , 

Carinthia  165 
Seistan,    Baluchistan..   227 
Sekondi,  Gold  Coast  . .   422 
Selmeczbanya,        Hun- 
gary       167 

Selsendorf,   Germany..   192 

Semi  R.,  Siberia  224 

Semionowski-Prisk, 

Russia  204 
Semipalatinsk-Semiret- 

chensk,    Siberia.  .210,  214 
Semiretchensk,  Siberia  214 

Sera-buri,    Siam    286 

Serdjiller,  Asia  Minor  225 
Serigano    Mine,   Japan  282 

Serio  R.,  Italy  153 

Seroa,  Eritrea   415 

Servia    156 

Se-San,    Annam 286 

Sesare,    N.E.    Rhodesia  430 

Sesia  R.,  Italy  153 

Sesupon,  Siam   286 

Seward   Peninsula, 

Alaska  492 
Shah  Abdul  Azim,  Per- 
sia       227 

Shalbuz-Dagh  Mt., 

Russia  209 
Shankala,    Abyssinia..  415 

Shantung,    China 271 

Shao-wu,    China    274 

Sheba,  Transvaal  ....  448 
Sheep  Creek,  S.E. 

Alaska  495 

Sheepstor,  Devon 121 

Sherbrooke.Nova  Scotia  466 
Sherbrooke,  Quebec  . .  469 
Shigor  R.,  Russia  ....  199 
Shinjio,  Formosa  ....  284 
Shintotsugawa,  Japan  279 
Shire  Highlands, 

Nyassaland  426 
Shirhatti  R.,  India  . .  256 
Shiribeshi  Prov.,  Japan  279 
Shorapur,  India   258 


GEOGRAPHICAL   INDEX 


679 


PAGE 

Shortcleuch     K..     Scot- 
land       138 

Shukoran,  Formosa  . .  284 
Shwedaung,   Burma    . .   266 

Shwegu,   Burma    266 

Shwegyin,  Burma   ....  269 

Shweli  R.,  Burma   266 

Shweli  R.,  China 274 

Shwe-Thamin-Chaung 

R.,  Burma   269 

Siam    286 

Siao-pin-tao, Manchuria  275 

Siberia  210 

Side     R.,     Tierra     del 

Fuego     660 

Sidi-Boussaib,  Tunis  . .  407 
Sieke,  French  Guinea..  418 
Sierra  Azul,  Mexico  . .  600 
Sierra  Cantabrica, 

Spain  145 
Sierra  da  Gaudarrama, 

Spain      147 

Sierra     de     Famatina, 

Argentina     655 

Sierra  do  Herval,  Brazil  646 

Sierra  Nevada   68 

Sierra  Nevada,  Califor- 
nia          508 

Sierra  Nevada,  Spain. .  147 
Sierra  Overa,  Chile  656,  657 
Sierra  Pinitos,  Mexico  600 
Sierra  Pinta  del  Bajio, 

Mexico    600 

Siflitz,  Carinthia 164 

Signal  Hill,  Natal  ....  455 
Sikarim.    Dutcb 

Borneo  295 

Sil  R,  Spain   145 

Silam,  Brit.  N.  Borneo  292 
Silensing,  Malay  States  289 
Silesia,  Germany  .  .162,  193 
Silver  Bow,  S.E.  Alaska  495 
Silver  City,  Idaho  62,  64,  516 
Silver  City,  Nevada  . .  522 
Silver  Cliff,  Colorado..  543 
Silverton,  Colorado  . .  561 
Simplon,  Switzerland..  151 

Singbhum,    India 249 

Sinnamari,  Dutch 

Guiana  643 
Sinnamari    R.,    French 

Guiana      642 

Sinoe  R.,  Liberia 418 

Siphanto,  Greece 161 

Siphnos,   Greece    161 

Siskiyou    Co.,    Califor- 
nia      514 

Sitka,  S.E.  Alaska  ....  495 
Sittaung  R.,  Burma  .  .   269 
Sixtymile  R,  Yukon  . .  481 
Sjui-Tsiet,    Dutch    Bor- 
neo      295 

Skadau      Mts.,      Dutch 

Borneo    295 

Skeena,     Brit.     Colum- 
bia       477 

Skippers,  New  Zealand  320 
Skwentna  R.,  Alaska..   494 

Skyros,  Greece  161 

Slate  Creek,  Quebec  . .  468 
Smaland,    Sweden    ....  197 

Snake  R.,  Idaho  68,  515 

Snake  R.  Oregon  ....  501 
Snake  R.,  Wyoming   . .  575 

Sneffels,  Colorado    557 

Snettisham,  S.E.  Alaska  495 


PAGE 

Snowy  R.,  E.  Australia  70 
Soemalatta,  Celebes  . .  297 
Sofala,  N.S.  Wales  . .  346 
Sogne  Fjord,  Norway. .  195 
Sola,  French  Guinea  . .  416 
Solomon  R.,  Alaska    . .  493 

Somaliland      416 

Somerset   122 

Sonapet,  India  . .' 260 

Sonora,  Mexico 599 

Sopp's  Arm,  Newfound- 
land      458 

Sorela  Oos,  Siberia....  216 
Sorghak,  E.  Turkestan  238 

Sorghak,  Tibet  235 

Sossva  R.,  Russia.. 199,  201 

South  Africa 50,    56 

South   America    ....61,  619 

South  Australia   384 

South  Caroline.  .51,  57,  586 
South  Dakota  .52,  98,  576 
South  Eastern  Alaska  494 
Southern      Cross,      W. 

Australia      399 

Southern  Klondike,  Ne- 
vada         530 

Southern  Rhodesia...  430 
South     Mountain,      N. 

Canolina    590 

South  Pass,  Wyoming  575 
South  Yenisei,   Siberia  210 

Soyopa,   Mexico 604 

Spain      145 

Spittal,  Carinthia  ....  164 
Spitzkop,  Transvaal  . .  453 
Spruce      Creek,      Brit. 

Columbia      476 

Srakeo,    Siam 286 

Stabioli,  Italy    154 

Stake     Burn,     Lanark- 
shire      135 

Starcke,  Queensland  . .  325 
Stavelot,  Belgium  ....  191 
Stawell  R.,  Victoria  360,  376 

Steiglitz,  Victoria   360 

Steinheide,  Germany..  192 
Stephen's  Green, Dublin  140 
StevensCo., Washington  500 
Stewart  R.,  Yukon  ....  481 
Stikine,  Brit.  Columbia  477 
Stope       Mine,       Malay 

States     289 

Stormont,  Nova  Scotia  466 
Strachwitz,  Germany..  193 
Stradtberge,  Germany  191 
Striegis  R.,  Germany..  193 

Struma  R.,  Turkey 160 

Strymon  R.,  Turkey  .  .  160 
Strymonic  Gulf,  Turkey  160 
Sturgeon  L.,  Ontario..  471 
Subansiri  R.,  India  . .  262 
Suches  R.,  Bolivia  .....  629 

Sucre,  Colombia   624 

Sudest    Id.,    Brit.    New 

Guinea    301 

Suihenkiaka..  Formosa  283 
Suisgill  R.,  Sutherland  136 
Sumatra,      Dutch      E. 

Indies     298 

Summit    Co.,    Colorado  540 

Sumpter,    Oregon 502 

Sunnyside  Basin,  Colo- 
rado      561 

Surigao    Prov.,   Philip- 
pine Is 292 


PAGE 

Surinam    639 

Sutherland 135 

Svappavara  Mine, 

Sweden  197 
Svartdal,  Norway  ....  196 
Svenningdalen       Mine, 

Norway     195 

Swakop     R.,      German 

S.W.  Africa 455 

Swaziland,  Transvaal 

51,  454 

Sweden   197 

Switzerland     151 

Sysertsk,  Russia  204 

Szechuen,  China   272 

Sztanizsa,   Hungary    . .  176 

Tabowie,  Korea 277 

Tacacoma,  Bolivia 629 

Tagalla,  Brit.  Sudan..  415 
Taganan,  Philippine  Is.  292 
Tagarak  Mine,  Siberia  221 

Tagil  R.,  Russia  202 

Tagula    Id.,  Brit.  New 

Guinea       301 

Tagus  R.,  Portugal    . .  143 
Taidon  R.,  Siberia  ....  215 
Taigonoskaia       Penin- 
sula, Siberia  225 

Tai  Parrit,  Sarawak . .  294 
Taiping  R.,  Burma  .  .  267 
Tairua,  New  Zealand 

308,  318 

Taiton,  Sarawak 294 

Taiwan  283 

Tai-Yen,  Annam   286 

Tajima  Prov.,  Japan..  280 
Takadama  Mine,  Japan  280 
Taku  Arm,  Yukon   ....  487 

Ta-lan,   China    273 

Talan,   Yunnan 64 

Talangting,  China  ....  273 

Talca,   Chile    656 

Talg  Id.,   Norway    196 

Tallawang,  N.  S.  Wales 

342,  344 

Tamaya,  Chile  656 

Tambaura,  French 

Guinea.  .416,  417 

Tamghaz,   Tibet    230 

Tamsoo,  Gold  Coast   . .  421 

Tana  R.,'  Norway    196 

Tana   R.,  Finland    198 

Tanah-Laut,  Dutch 

Borneo   295 

Tanaka,  Formosa  ....  284 
Tanana  R.,  Alaska...  491 
Tangier,  Nova  Scotia 

461,  466 

Tanjil,  Victoria    360 

Tankisso    R.,    French 

Guinea  418 
Tank-kogae,   Korea...  276 

Tapah.  Perak    288 

Tapanoeli,  Sumatra   . .  300 

Taracol,  Korea     277 

Tarcoola,  S.  Australia  385 
Taria  Mine,  Brazil  . .  653 
Tarkwa,  Gold  Coast   . .  421 

Tarn  Dep.,  France  148 

Tarnagulla,  Victoria  . .  371 
Tarrangower,  Victoria 

359,  371 
Tarwaragheri,  India..  244 
Tasei  Mine,  Japan  ....  281 
Tasmania     70,  71,  378 


080 


GEOGRAPHICAL    INDEX. 


PAGE 

Tassara,    Brazil    650 

Tatarka,  Siberia  ....  218 
Tatarskaia  R.,  Siberia  217 
Tati,  Berhuanaland   . .  435 

Tavay,  Burma  269 

Tavda  R..   Russia    201 

Tay  L.,  Perthshire 138 

Tay  K..  Perthshire  . .  138 
Taymouth.  Perthshire..  138 
Tcheliabinsk,  Eussia 

74,  204 

Tchernaia,  Siberia 218 

Tchlia,  L.,  Siberia  ....  224 
Tchornaia  R..  Russia..  206 
Teberibi,  Gold  Coast  .  .  421 
Teetulpa,  S.  Australia  385 
Tegucigalpa.  Honduras  610 

Teia  R.,  Siberia 215,  218 

Teisskaia,   Siberia    ....  218 

Tekero,  Hungary 177 

Tekes  R„  E.  Turkestan  238 

Teller,   Colorado    562 

Telluride,  Colorado  . .  558 
Temora,  N.S.  Wales  . .  343 
Tenasserim,  Burma  . .  269 
Ten-mile.  Colorado    ....  540 

Tennessee 586,  596 

Terawhiti    Cape,     New 

Zealand    322 

Ters  R,  Siberia   215 

Teshio  Prov.,  Japan  . .  279 
Teshiro  Prov.,  Japan  . .  279 
Tesserete.  Switzerland..  151 
Tete,     Portuguese     E. 

Africa     430 

Texas,  United  States  . .  567 
Thames,  New  Zealand  309 
Than-Hoa,  Annam  ....  286 
Thelemark,  Norway  . .  196 
Thok-Daurakpa,  Tibet..  234 

Thok-Dikla,   Tibet    234 

Thok-Jalung,  Tibet  ...  233 
Thok-Maroobhoob, 

Tibet  234^ 
Thok-Nainmo,  Tibet  .  .  234 
Thok-Ragyok,  Tibet  . .  234 
Thok-Sarkong,  Tibet  . .  234 
Thok-Sarlung,  Tibet  ..  234 
Thok-Thasang,  Tihet  .  .  234 
Thornborough,  Queens- 
land        326 

Thunilthan    R.,  Siberia  225 
Thuringer    Wald,    Ger- 
many         192 

Thursday    Id.,   Queens- 
land        325 

Tiari    Mts..    New    Cale- 
donia        303 

Tibbooburra,  N.S. 

Wales  342 

Tibet   228 

Tibi-darya.  Siberia 214 

Tibika  R.,  Siberia   217 

Ticino,    Switzerland    . .   151 

Ticino  R.,   Italy    153 

Tierra  del  Fuego   660 

Tikhona-Zadonsky, 

Siberia  221 
Tilkerode,  Germany  . .  192 
Tilt     Cove,     Newfound- 

il     458 

Timok  Valley,  Servia 

156,  160 

Tintic.  Utah    565 

Tiolo,  French  Guinea..  418 
Tipuani   II..  Bolivia    . .   629 


PAGE 

Tira,  Brit.   Sudan    414 

Titiribi,  Colombia   623 

Titmaringhausen,    Ger- 
many      191 

Tmolos  Mt.,  Asia  Minor  225 
Tobique  R.,  New  Bruns- 
wick      467 

Tobolsk- Akmonlinsk, 

Siberia  210,  211 

Togoland,    Africa     423 

Tokatea,  New  Zealand  308 
Tolima,  Colombia    622,  626 

Tom  R.,  Siberia   215 

Tombstone,  Arizona   . .  537 

Tomsk,  Siberia  210,  214 

Tongking,    Indo-China    285 
Tongoue,     New     Cale- 
donia      303 

Tonopah,  Nevada  ..64,  526 
Topdal  R.,  Norway  . .  196 
Toplicza,  Hungary  ....  180 
Toppa  Valley,  Italy  . .  153 
Topuldodi,  India  ..244,  258 
Torbockhill,  Scotland..  138 
Tordrillo   Mts.,   Alaska  494 

Tornea,   Sweden    197 

Tornea  R.,  Finland  . .  198 
Torrisdal  R.,  Norway. .   196 

Totok,  Celebes   298 

Toumani  Mine,  Siberia  216 

Tragni.  Carinthia  164 

Transbaikalia,  Siberia 

210,  218 
Transvaal,  S.  Africa 

57,  435 
Transylvania,  Hungary 

66,  169 
Transylvanian  Alps  .  .  119 
Traz-os-Montes      Prov., 

Portugal      144 

Treadwell,  S.E.  Alaska  495 
Tres  Brazos  R.,  Tierra 

del  Fuego  660 

Tresztya,  Hungary....  180 
Trewarda,  Cornwall    .  .   121 

Trinidad       618 

Trinity  Co.,  California  514 

Tripoli,   Africa    407 

Trivera,   Italy    155 

Troicza,  Hungary    180 

Troitzk  Mine,  Russia..  206 

Troitzki,  Siberia   223 

Tsangpo  R.,  Tibet   237 

Tsi-tz'-Kouho,    Manchu- 
ria         276 

Tucson,  Arizona   537 

Tucuman,  Argentina  . .   655 

Tui,  Malay  States    289 

Tumat  R.,  Abyssinia..  415 
Tumberumba,   N.S. 

Wales  343 

Tumkur,  India  244,  259 

Tunis,  Africa   407 

Tuong-Dong,  Annam  .  .   285 

Turan,  Annam 285 

Turkey   160 

Turnagain   Arm, 

Alaska  493 
Turon  R„  N.S.  Wales..  346 
Turrerich.  Perthshire.  .  138 
Tuyen-Kwang       Prov., 

Indo-China   285 

Twelve   Apostles   Mine, 

Hungary    184 

Tvddyn-gwladys,         N. 
Wales     124,  125,  130 


PAGE 

Tyndrum,  Perthshire..  138 
Tyn-y-Penrhos,  N. 

Wales  131 
Tyrol,  Austria  ....119,  163 
Tzarevo-Alexandrovski, 

Russia    208 

Udereia  R..  Siberia  . .  217 
Udoronga  R,  Siberia..  217 
Udu  Mts.,   Dutch 

Borneo  295 
Uganda  Protectorate..  425 

Ugo  Prov.,  Japan    279 

Uibaka  R.,  Siberia 217 

Uisge         Duibh         R., 

Sutherland  136 

Ularring,  W.  Australia  398 
Ullie  R.,  Sutherland  . .  136 
Um  Eleagha,  Egypt  ...  413 

Em   Esh,   Egypt    413 

Um  Gariart,  Egypt 

411,  412,  414 

Um  Rus,   Egypt    413 

Umtali,  Portuguese  E. 

Africa    429 

Umtoot,  Egypt  413 

Umzinto,    Natal    455 

Uncompahgre,  Colorado  557 

Unda,  Siberia  220 

Unga  Id.,  Alaska    494 

United  States  of 

America  488 

Unsan,  Korea   277 

Upper     Goulburn     R., 

Victoria     360 

Upper  Sesia  Valley, 

Italy  153 
Upstart    Cape,  Queens- 
land     327 

Ural    Mts.,    Russia 

74,  119,  199 
Uralguinski,  Siberia  . .  220 
Uralicha  R.,  Russia  . .  202 
Uralla,    N.S.    Wales    ..  343 

Urbas  R.,  Bosnia  165 

Urmi  R.,  Siberia 222 

Uruguay     654 

Ushuaia,  Argentina  ...  660 

Usotannai,  Japan   279 

Utah,  United  States 

62,  563 

Uyu   R.,   Burma    268 

Val  Corsente,  Italy  . .  153 
Val  de  Challant,  Italy  155 

Valdivia,  Chile    656 

Vale    of    Clwydd,    N.S. 

Wales    341 

Valea    Arszului,    Hun- 
gary        184 

Valea  Boji.  Hungary..  171 
Valea  Mori,  Hungary  184 
Valea  Rosia,  Hungary  172 
Valencia,  Venezuela  . .  633 

Vallongo,   Portugal 144 

Val   Moriana,  Italy    . .  155 

Val  Toppa,  Italy  154 

Vancouver  Id..  Brit. 

Columbia  480 

Varosluk,  Bosnia  166 

Vellosa,  Brazil  650 

Venezuela     633 

Veraguas,  Panama  ....  614 
Verde    R.,    Tierra    del 

Fuego     660 

Verespatak,   Hungary 

66,  172 


GEOGRAPHICAL    INDEX. 


G81 


PAGE 

Verkhny-Uralsk, 

Russia  204 
Vermilion  R.  Ontario  472 
Vermont.  United  States  585 
Vernayaz,  Switzerland  151 
Victoria,  Australia  71,  359 
Victoria.    Colombia     .  .   626 

Vigra,  N.  Wales   124 

Vilenisa.  Bosnia  166 

Villafranca,  Spain  ....  145 
Villa  Rica  L.,  Chile    . .  656 

Vincenzi,  Tyrol  163 

Vinh-Muy,  Annam  ....  286 
Vinh-Ninh,  Annam....  286 
Virgilina,  Virginia  ....  586 
Virginia,  United  States  566 
Virginia  City.  Nevada..  522 
Viriguas,  Panama  ....  614 
Vishera  R,  Russia,  ....   199 

Visvar,  Hungary   189 

Vitim  E.,  Siberia  ....  220 
Vitimkhane,  Siberia  .  .  221 
Voel,  N.  Wales   ...  .128,  131 

Voitsk.  Russia   199 

Vranitza  Mts.,  Bosnia  165 
Vryheid,  Transvaal  . .  454 
Vulkoj,   Hungary    .66,  175 

Vungwini,  Natal   455 

Vychegda  R.,  Russia  . .   199 

Wa,    Burma    269 

Wadi  Abbas,  Egypt  . .  408 
Wadi  Allaghi,  Egypt  . .  408 
Wadi    Hammama, 

Egypt  412 

Wadi  Sus,  Morocco  407 

Wadnaminga,    S.    Aus- 
tralia        385 

Wahlstatt.  Germany  . .  193 
Wahnapitas  L.,  Ontario  471 
Wahnapitas  R  ,  Ontario  472 
Wahsch   R.,   Siberia 

211,  214 
Waihi,  New  Zealand 

65,  312,  317 
Waimangu,    New    Zea- 
land        322 

Wainaad,  India.240,  250,  259 
Waiotahi     Mine,     New 

Zealand     311 

Waipori,   New   Zealand  320 
Waitekauri,    New   Zea- 
land        317 

Waldeck,  Germany  ....  191 
Waldshut.  Germany    .  .   190 

Wales     123 

Walhalla,  Victoria 

70,  360,  361 
Wandilgong,  Victoria..  361 
Wanlock  Head,  Lanark- 
shire       135 

Wanlock   R.,  Scotland    138 
Wanlock   Water,   Scot- 
land        133 

Waria  B..  German  New 

Guinea     302 

Warme       Czamos      R., 

Hungary    188 

Warren,  Idaho  515 

Washington,        United 

States     499 

Wassaic,  New  York    . .  585 


PAGE 

Wassau  Mine,  Gold 

Coast  422 

Wat  ana,  Siam  286 

Waver  ley,  Nova  Scotia  466 
Waxhaw,  N.  Carolina..  594 
Way  L.,  W.  Australia  396 
Weaver  Mts.,  Arizona..  537 
Wedderbnrn.  Victoria..  300 
We-ganga  R.,  Ceylon . .   263 

Weida,  Ger.many  192 

Weihaiwei,  China   272 

Weisenau,     Carinthia..  164 
Welawe-ganga  R.,  Cey- 
lon      263 

Wendron,  Cornwall  .  .  121 
Weralupe,  Ceylon  ....  263 
Werra  R.,  Germany    . .   192 

Wesel,  Germany    191 

Westbury,  Quebec    ....   469 
West    Coast,    New    Zea- 
land       306,  318 

Western  Australia 

49,  55,  387 
Western    Csetras    Mts., 

Hungary    182 

West  Gore.   Nova 

Scotia  465 
Westeim,  Germany   .. .  .   191 

West  Indies   597 

Westland,  New  Zealand   318 
Westmanland,    Sweden  197 
Westpha'ian  Mts.,  Ger- 
many         191 

West  Pilbara,  W.   Aus- 
tralia         393 

Whakarewarewa,    New 

Zealand     322 

Whalton,  Somerset  ....  122 
Whiteburn,  Nova 

Scotia  466 
Whycocomagh,  Nova 

Scotia  461,  465 
Whyte  R.,  Tasmania  . .  384 

Wicklow  Ireland 141 

Wijai  E.,  Russia 201 

Williams'    Creek,    Brit. 

Columbia      474 

Willow  Creek.  Brit 

Columbia  476 
Windhoek,  German  S.W. 

Africa    455 

Wine    Harbour,    Nova 

Scotia     466 

Winterville,   Oregon    .  .   502 
Wipp  Thai,  Tyrol    .'. . .   163 
Wittenweyer,  Germany  190 
Witwatersrand,    Trans- 
vaal      51,  56,  95,  435 

Wiwo  R.,  German  New 

Guinea     302 

Wolumba,  N.S.  Wales  358 
Wondalli,  India. 

239,    244,  258 

Wonder,  Nevada  525 

Wood  R..  Idaho    516 

Woodenbridge.  Ireland  141 
Woodlark      Id.,      Brit. 

New   Guinea    300 

Woods  Point,  Victoria 

70,  360,  366 
Wiirbenthal,    Austrian 
Silesia    162 


PAGE 

Warigam,  India   249 

Wyalong,  N.   S.   Wales  355 

Wyg  R.,  Russia 199 

Wyoming, United  States  575 
Yackandandah,        Vic- 
toria       361 

Yagtag  Cape,  Alaska.  .   493 

Yakatsk,  Siberia  210 

Yak-Su  R.,   Siberia 212 

Yakutsk,    Siberia    220 

Yalgoo,  W.  Australia. .  396 
Yalwal,  N.  S.  Wales  . .  356 
Yamagano  Mine,  Japan  282 

Yamo,  Japan     282 

Yang-tse  R.,  China 272 

Yani,  Bolivia     629 

Yaqui  R.,  Haiti    616 

Yarkand,  E.  Turkestan  237 
Yaro-Tsangpo.  Tibet  . .  237 
Yarra  R.,  Victoria  ....  360 
Yarri,  W.  Australia  . .  399 
Yarrow  R.,  Scotland  . .  138 
Yaruari,  Venezuela  59,  633 
Yarumal.  Colombia  . .  625 
Yatella,  French 

Guinea  417 

Yatton,  Queensland    . .  337 

Ye  R.,  Burma    269 

Yen-Ching,    China    273 

Yenisei,  Siberia  .210,217 
Yeniseisk,  Siberia  ....  215 
Yerilla,  W.  Australia..  398 

Yezo,  Japan    278 

Yilgarn,  W.  Australia  399 
Yodda,        Brit.        New 

Guinea    301 

Yonya  R.,  Siberia   220 

York     Harbour,     New- 
foundland        458 

Yorke  Peninsula, 

Queensland  325 

Yoro,  Honduras    610 

Youkon-din-miao,  Man- 
churia       275 

Yuen-san,  Korea  277 

Yii-erh-yai,    China    ....  271 

Yukon    481 

Yuktu  Gol,  Tibet 235 

Yunnan,  China     273 

Yzabal,  Guatemala....  608 
Zabaikalskaia,  Siberia  218 
Zalathna,  Hungary  .  .  176 
Zamboanga,  Philippine 

Is 292 

Zambusi  R.,  Portuguese 

E.  Africa 429 

Zaragoza,  Colombia  . .  625 
Zaruma,   Ecuador    ....   627 

Zeia,  Siberia   211,  222 

Zeleznica  R.,   Bosnia..   165 

Ziller  Thai.,  Tyrol  163 

Zimbabwe,  S.  Rhodesia  430 
Zirknitz   R.,   Carinthia  165 

Zlot,   Servia    157 

Zoppatenbach,         Ger- 
many         193 

Zoutspansberg,    Trans- 
vaal       448 

Zui-ho,  Formosa   283 

Zululand,  S.  Africa    . .     51 


INDEX   TO   AUTHORS    CITED. 


PAGE 

Adam   25,  37 

Aguilera    62,  598 

Ahlburg       144 

Alford  410,  412,  413 

Allen     27 

Anderson  51,  454.  455 

Andrews    323,  345,  347,  357 

Antissier    148 

Antony    37 

Armas      419 

Arnold      500 

Arsandaux     416 

Atherton    •  38 

Atkin     474 

Attwood       634 

Bagg     604 

Bailey     467 

Ball    325 

Baragwanath    371,  373 

Barbarena     609 

Barlow    7,  482 

Barrell     572 

Basedow   386,  387 

Bauer 187,  188,  189,  277 

Becker  ...  .6,  57,  95,  104,  290,  292,  445, 
446,    465,   494,    495,   525,   584, 

585,      588,      589,      591,      592,  595 

Belfleld    288 

Bell     316,  322 

Bellew    227 

Berg     53,  652 

Bererfeld 23 

Berkey  531 

Bernard 148 

Berrington    433 

Beyschlag      163 

Bischoff       39 

Blake      100 

Blatchford     400 

Blundell    415 

Bodenbender      655,  656 

Bockh       167 

Bogdanovitch   209,  225,  274 

Bogovin    211 

Bollivian    628 

Bonney     634 

Booth    645 

Bordeaux   216,  219,  224,  448,  450,  454 

Bourdariart     61,  147 

Boussingault     23 

Boutwell    566 

Bradford      364,  366 

Brain      661 

Branner     645 

Brauner 28 

Breidenbach       144,  146 

Breithaupt     37 

Brent      471 

Brewer     474 

Bricchetti — Eobecchi      416 


PAGE 

Briggs     227 

Bristowe      609 

Brock     100,  470,  472,  477,  479 

Brooks      51,  493,  496,  498 

Brown,   L.   B 216 

Brown,  H.  Y.  L 385,  386 

Browne     82 

Bruce        235 

Bruhns     191.  194 

Bucking       297 

Burrows       604 

Burton      226 

Buttgenbach     424 

Buttikofer      418 

Cairnes    488 

Calvo     612 

Cameron,  V.  L 424 

Cameron,  W.  E 325,  326,  328,  332 

Campbell     7 

Canaval       164 

Caraven-Cachin    148 

Carne     350,  358 

Carnot      35 

Catharinet    100 

Chalmers      432,  469 

Chaper     419 

Chenhall      110 

Choff  at     423 

Church    525,  537.  608 

Clarke     7 

Clement       51 

Clifford    288 

Coleman   7,  470 

Collier      500 

Collins 608 

Coomara-Swamy     263 

Cornet      424 

Corstorphine    51,    56,   438,    441,  446 

Cortes    659,  662 

Cossa     28 

Couyat     430 

Crespi 612 

Cross      543,   554,   556,  560 

Crowe       284 

Cullis     123 

Cumenge    25,  39 

Cuninghame      423 

Cunningham-Craig     618 

Curie    271,  277,  661 

Curtis      6,  525 

Daintree      81 

Dana     18,  25,  31,  33 

Davidson     283 

Daw       195 

Day       617 

De  Launay   95,  119,  153,  427,  655 

Del  Mar,  Alexander  278 

Del  Mar,  Algernon    526 

Del   Rio    25 

Delvaux       644 


684 


INDEX    TO 


PARE 

De  Moeller  208 

Denny      454 

Derby      53,  648 

H.-plagnes     418 

Devereux    98,  581 

Dewalque    148 

Dickson       7 

Dieulaf  ait     6 

Diller     226,  502 

Diodorus     148 

Doelter      103,  188 

Dorffel      450 

Domeyko     659 

Don   ....38,  73,  104,  108,  318,  320,  367,  370 

Dresser    469 

Du  Bois   639 

Duenas     632 

Dun       344 

Dunn.  E.  J 336,  337,  370 

Dunn,   R.   L 94,  510 

Dunstan     27,326,327,328,  339 

Eckel      52 

Edman     15 

Egleston     81,  104 

Eilers       539 

Ells       469 

Emmons    S.  F 12,  98,   541,  543, 

557,  565,  577,  580,  586 

Emmons,   W.   H 526,    534,  560 

English    226 

Erdmann     197 

Evans    645 

Fairbanks     94,  506 

Fantonetti      154 

Faribault       461 

Farish     539,  604 

Farrington    620,  622,  623 

Federov     201 

Finlay      627 

Fircks       198 

Fletcher      36 

Flett       226,  624 

Floyer      410 

Fock      ^ 86 

Foote     257 

Forbes      162 

Forchhammer      6 

Forstner      69 

Forsyth    238 

Foster,  Le  Neve  634 

Foullon      166 

Fraser     307  308,  309,  316 

Frochot    629,  630 

Frobel       25 

Fuchs    655 

Futterer      204,   206,  407 

Gamier    274 

Garrey    526,    534,  540 

Garrison    616 

uel    426 

Geikie    293 

Genth      24,   28,  539 

Gesell      174 

Gibson    394,  397,  399 

Gilpin       462 

Glaser      416 

Glas8er    ..210,214,217,220,221,223,  302 

Gmelin     199 

dman    290 

Gordon       84,  279 

ham    288 

nger      620,  639 

ut     584 

Graton     548,568,569,592,  593 

u'ory   ....72,  95,  97,  360,  362,  363, 

364,  383,  384,  432,  446 


PAGE 

Griesbach       227 

Grimm     188 

Guerrassimov    222 

Gunther      546 

Guppy  618 

Gwillim    476 

Hager       585 

Hague    62,525,  536 

Hall    109,   112,  371,  431,  451 

Halse      620,  624 

Hamilton       277 

Hammond       96 

Hardman    391 

Harrison    6,    636,  638 

Hastings      531 

Hatch     ....51,  56,  260,  292,  295,  432, 

438,  441,  445,  446,  450 

Hayden     237,  260 

Hayes     615 

Hedges     454 

Helmhacker 15,  100 

Henderson      443 

Hennecke     227,  639 

Herodotus     160,  161 

Hershey     509,  614 

Herrman      662 

Herzig     410 

Hess       492 

Higgins      628 

Hill      617 

Hitchcock    584,  585 

Hobbs      32 

Hogg     359 

Holmes     584 

Holy     162 

Hoover     38,  270,  271,  405 

Horvath     188,  189 

Hoskold      656 

Howitt      360,  369 

Howley     458 

Hume     412 

Hundeshagen        300 

Hussak     53,  650 

Hutchins     492 

Hutton      54 

Iddings      62,  525 

Ingalls     536 

Irving     558,  562,  578,  583 

Ivanov      223 

Ivey      299 

Jacewski     218 

Jack   ....273,   274,  326,  329,  333,  334, 

336,  337,  339 

Jackson      55 

Jaggar     577 

Jalhay     610,  611 

Jaquet    100,102,349,  357 

Jenney     114 

Jervis     153 

Johnston     273 

Jolly     381 

Jones     146 

Jorissen      438 

Jovanovitch      : 156,  158 

Judd      586 

Kahlbaum      22 

Kaiser     657 

Karpinsky       75,    203,  204 

Katzer      166,  643 

Kemp     5,  8,  77 

Kinahan      140 

King      525 

Kitson      360 

Knight      7,  472 

Knox      513 

Kokscharov      199 


AUTHORS    CITED. 


685 


PAGE 

Korotkoff    216 

Korsuchin     225 

Kosmann    I94 

Kosmas     416 

Krafft      23 

Krause     450 

Krusch      162,    165 

Kuntz     455 

Kynaston     448 

Lacroix     102,     429 

Laird     607 

Lake  247 

Lakes    '.'.' 516,  541,  543,  562,     602 

Lamartiny     4i7 

Landes     499 

Lane       39,      '" 

Laroza     630 

La  Touche     269 

Laur      148 

Lawson      47" 

Leach      22 

Le    Brun-Renaud    418 

Leclere     273 

Leggett      610 

Leibius      22 

Lemiakin     225 

Le  Neve  Foster    634 

Lenher      28,  105,  109,    112 

Lenicque      154 

Leonhard      I44 

Lett     "30 

Levat     213,219,223,641,     642 

Lewis     19 

Lidgey      367 

Linck     638 

Lindgren  .5,  6,  52.  53,  58.  59,  64,  65, 
69,  74,  94,  108.  316,  360,  369, 
375,  389,  404,  468,  489,  490, 
501,  504,  508,  509,  511,  514, 
515,  516,  517,  519,  520,  536, 
537,  541,  548,  554,  563,  566. 
568,    569,   570,   571,    575,   589, 

590,  599,     650 
Liversidge  .13,  19,  39,  41.  82,  83,  102, 

104,     108 

Llewellyn     410 

Lodge    90 

Loram       657,     658 

Loranski     215 

Louis,  H 4,  266,  453,     456 

Lowag       163 

Lucchesi      37 

Lungwitz     39,    637,     638 

MacAlister     412 

MacCarthey       407 

McCarthy,    E.    T 608 

Macco        423.     455 

McConnell    83,   482,     486 

MacDonald    479 

Macdonald,    W.    F 356 

Mclvor 24 

McKay     308,  318,     323 

McKinley     617 

Maclaren  .8,  47,  48,  55.  61,  96,  101, 
104,  143,  156,  228,  237,  238, 
246,   262,   265,    308,   309,   322,     332 

McLaughlin      509 

Maclaurin       37,     79 

MacLeod      331 

Maier     225 

Maitland    .50.   55,   56,   83,    300,   329, 

389,   390,   391,   393,   394,   403,     405 

Malsch     632 

Margottet      23,      28 

Martin     493,     494 

Mawe 650 


PACE 

Meister     217,     218 

Mennell   27,  431.  432,  433,     434 

Mercer      627 

Merensky      51 

Merrill      100,111,598,599,    600 

Merritt     4n 

Mesny      235 

Middelburg      640 

Middlemiss      287 

Mierisch      611 

Miers    33 

Miller      4?2 

Milward     661 

Mitscherlich      23 

Moricke      100,656,657,     659 

Moffltt     493 

Moissan      22,23,37,     110 

Molengraaff      296,  297,     298 

Monroe     5 

Monteiro     423 

Montgomery     378,  379,     381 

Moon     117 

Morgan      316 

Muir      37 

Munster      41 

Murray      301 

Naumann         15 

Navarro      148 

Neal     431 

Nenadkevitch       25 

Naumann        15 

Newbery,  J.   C 81 

Nichols     291,  292.  620,   622,     623 

Nitze     206,  586,     591 

Nogues     148 

Obalski      470 

Obrutchev      222 

Ordonez       62,     598 

Ostwald      40 

Owen      539,     620 

Packard     464 

Paillette      148 

Palache     32 

Park     54,  89,  309.    321 

Paull     331 

Pausanias     161 

Pearce      104 

Pearson      654 

Pelatan     .285,  286,  302.  407,  418,  419,     641 

Penrose      63,     554 

Pervinquiere 276,     278 

Petre     620 

Phillips,   J.   A 4 

Pinder      300 

Pirsson      573 

Pittman      35,342.350,353,     354 

Pliny      23,  82.  145,     152 

Pohlmann      661 

Poni      161 

Poole     465 

Posepny    ..5,   162,   164,   176,   188,   203,     204 

Posewitz      292,     295 

Powell     636 

Pratt 537 

Prichard      509 

Prindle     492 

Pumpelly      4 

Purington    74,  203,  206,  221,  311, 

556,    559,   560.     562 

Rainer      189 

Rands     326.  329,  339,     340 

Ransome.  .531,  532,  535.  554,  557,  560,     562 

Raverty      229 

Reid     94,  524,  525,     538 

Restrepo     613,  620,     626 

Reusch     195 


G86 


INDEX    TO 


Kiehardson     123, 

Richthofen     

Rickard,  F 480, 

Rickard,  T 

Rickard,  T.  A 27.  35,  104,  111, 

149,   321,   337,   364,   370,    405, 
531,  546.  554,  560, 

Rickmcrs     

Robellaz       

Robertson      

Rogers      

Rose,  G 15, 

Rose.  T.  K 

Rosenberg-Lipinsky     

Ross     

Rothwell     

Rucker     

Ruer      

Russegger 

Sachs      

Samwell      

Sandberger     

Sandeman     

San  Roman      

Sarlin      

Saugy      

Sawkins     

Sawyer      421,  422,  429, 

Scheibe     

Schenck     

Srhindler      

Schmeisser     302,  423, 

Schmidt,    A 

Schmidt,  C 151,  152, 

Schmitt     

Schneider     26, 

Schrader     

Schrauf     

Schuller     

Schultz      519, 

Schultze      

Schwartz      456, 

Schweinf  urth     

Scott,  H.   K 52,  646,  649,   653, 

Scrivenor 287,  288, 

Scrutton      

Seamon     

Selwyn     

Sementchenko      

Semper    171,  173, 

Shepard      

Simrnersbach      

Simonin     

Simpson,   E.   C 

Skewes     

Skey     81.  104, 

Sleeman     412, 

Slichter     

Smeeth     

Smith      

Smith,   F.   C 32, 

Smith,   G.   0 499,   566, 

Soetbeer      

Sollas     65,  307,  308, 

aenschein     

stadt     

iy      

Speak      

Spencer,  A.  C 495,  496,  560, 

>]>encer,  J.   W 

spencer,  L.  J 29,  34,  35, 

sPurr   60,  64,  84,  102,  487    491 

492,   494,   499,    527,    530,   531, 

a±     ,  532,  540, 

Stache      .    . 

l     


PAGE 

661 

188 
542 
618 


605 
214 

25 

6 

457 

204 

39 
194 
523 
616 
165 

25 
415 
193 
419 
6 
381 
662 
198 
286 
618 
456 
100 

95 
227 
426 
192 
155 
163 

40 
493 

36 

23 
575 
100 
457 
414 
655 
293 
294 

25 

81 
221 
188 

24 
226 
148 
404 
168 
108 
414 
9 
251 
471 
583 
585 
630 
314 

26 

41 
147 
277 
575 
615 
404 


565 
188 
202 


PACE 

Stelzner      95,  659 

Stephens      110 

Steuart 448 

Stevens     548,  554 

Stokes      104,  109 

Strabo     23,  145,  148,  152,  160 

Strap    150 

Stringer     475 

Sturm      22 

Stutzer     150 

Sundbaerg     197 

Taumann      25 

Tchichatchef       226 

Thies     593 

Thilo     188 

Thoma     225 

Thomas     307 

Thord-Gray     451 

Tietze      227 

Tippenhauer      616 

Tornebohm     197 

Tovey     215 

Tower      566 

Townsend      434 

Trentini     599 

Treville     620 

Truscott   59,  295,  296,  298,  299,  419 

Tschernychew     204,  207 

Turner     614 

Twel vetrees     378,  380,  381 

Tyrrell     g-L  ,  482 

Ulrich      24,  26,  81 

Ulsmann     38 

Van    Hise 3,  114 

Van  Isschot      628 

Van   Schelle      295 

Vaughan     615 

Verschoyle     272 

Vogelsang      270 

Vogt     196 

Voit    51,95,97,  455 

Vom  Rath    15,  32 

Von  Arzruni     202 

Von    Cholnoki       276 

Von  Cotta   188,  191 

Von  Fellenberg   188 

Von  Gernet    189 

Von  Hauer     188 

Von  Krafft     212 

Von  Papp      188 

Wagoner          41,  107 

Walker     7 

wan  :;;;;  633 

Wallace     430 

Waller      378 

Wallis-Budge    408 

Wankowski       599 

Wappaeus     649 

Ward    19 

Watt      351',  355 

Weed  12,  572,  573,  574,  586,  600,  603 

Weigall      279 

Weinecke      193 

Weisler     41 

Weisz 188 

Welles     543 

Wells     472 

Werner      iq 

Whitelaw     362,  364 

Wliitney     4>  586 

Wilkens      586,  591 

Wilkinson,  C.  S 81,  337 

Wilkinson,  H.  L 94F  375 


344 
377 


Wilkinson,   W.   F 422      435 

Williams    '.'.'.'.' .38',     592 

Wllm     25 


AUTHORS   CITED. 


687 


PAGE 

Wilson      334 

Winchell      584 

Winslow     559 

Woakes      613 

Wolfskron     163 

Woodman      461,  464 

Woodward     393,394,395.396,  398 

Woolnough    304 


PAGE 

Wylie    226 

Wyssotsky      206 

Yavorovsky     223 

Yunge     662 

Zaitzeff     216,  217 

Zalinski      525 

Zarco     628 

Zelizko       162 

Zsigmondi      40 


LONDON : 

Taylor,  Gaenett,  Evans,  &  Co.,  Ltd. 
Also  at  Manchester  and  Reddish. 


015 


AUd  t  j  mtj 


(